| United States Patent Application |
20150004633
|
| Kind Code
|
A1
|
|
Sisco; Kenneth
;   et al.
|
January 1, 2015
|
ASSAYS AND METHODS FOR THE DIAGNOSIS OF OVARIAN CANCER
Abstract
Provided are methods for diagnosing ovarian cancer or assessing the risk
of developing ovarian cancer in a subject by measuring, in a biological
sample from the subject, the amount of IL-6 and comparing the amount of
IL-6 measured to a predetermined IL-6 cutoff value. Also provided are
methods that further include measuring, in the biological sample, the
amount of two or more biomarkers selected from the group consisting of
transthyretin, apolipoprotein A1, transferrin, .beta.-2 microglobulin,
and CA 125 II. The amount of IL-6 and biomarkers are useful in the
diagnosis of ovarian cancer, and individuals can be identified as having
ovarian cancer when the amount of IL-6 is greater than the IL-6 cutoff
value and/or the biomarker score is greater than the biomarker score
cutoff value.
| Inventors: |
Sisco; Kenneth; (Chantilly, VA)
; Chou; Peter; (Chantilly, VA)
|
| Applicant: | | Name | City | State | Country | Type | Quest Diagnostics Investments Incorporated | Wilmington | DE | US | | |
| Assignee: |
Quest Diagnostics Investments Incorporated
Wilmington
DE
|
| Family ID:
|
48948147
|
| Appl. No.:
|
14/377069
|
| Filed:
|
September 26, 2012 |
| PCT Filed:
|
September 26, 2012 |
| PCT NO:
|
PCT/US12/57315 |
| 371 Date:
|
August 6, 2014 |
Related U.S. Patent Documents
| | | | |
|
| Application Number | Filing Date | Patent Number | |
|---|
| | 61596107 | Feb 7, 2012 | | |
|
|
| Current U.S. Class: |
435/7.92 ; 205/792; 702/19 |
| Current CPC Class: |
G16B 40/30 20190201; G01N 2333/5412 20130101; G01N 33/57449 20130101; G16B 40/00 20190201; G01N 2800/50 20130101; G16H 50/30 20180101; G06F 17/18 20130101; G16B 40/20 20190201 |
| Class at Publication: |
435/7.92 ; 205/792; 702/19 |
| International Class: |
G01N 33/574 20060101 G01N033/574; G06F 19/00 20060101 G06F019/00; G06F 17/18 20060101 G06F017/18; G06F 19/24 20060101 G06F019/24 |
Claims
1. A method for identifying the risk of an individual for having ovarian
cancer comprising: (a) measuring, in a biological sample from the
subject, the amount of IL-6; (b) comparing the amount of IL-6 measured in
step (a) to a predetermined IL-6 cutoff value; and (c) identifying the
individual as being at risk for having ovarian cancer when the amount of
IL-6 is greater than the IL-6 cutoff value, and identifying the
individual as not at risk for having ovarian cancer when the amount of
IL-6 is less than the IL-6 cutoff value.
2. The method of claim 1, wherein the predetermined cutoff value is
derived from a measurement of the amount of IL-6 in one or more subjects
that do not have ovarian cancer.
3. The method of claim 1, wherein the biological sample is serum or
plasma.
4. The method of claim 3, wherein the IL-6 cutoff value is about 5 pg/ml.
5. The method of claim 1, further comprising (i) measuring, in the
biological sample, the amount of a biomarker selected from the group
consisting of transthyretin, apolipoprotein Al, transferrin, .beta.-2
microglobulin, and CA 125 II, (ii) comparing the amount of the biomarker
measured in step (i) to a predetermined biomarker cutoff value; and (iii)
identifying the individual as being at risk for having ovarian cancer
when the amount of IL-6 is greater than the IL-6 cutoff value and the
amount of the biomarker is greater than the biomarker cutoff value, and
identifying the individual as not at risk for having ovarian cancer when
either or both of the amount of IL-6 is less than the IL-6 cutoff value
and the amount of the biomarker is less than the biomarker cutoff value.
6. The method of claim 1, further comprising (i) measuring, in the
biological sample, the amount of two or more biomarkers selected from the
group consisting of transthyretin, apolipoprotein A1, transferrin,
.beta.-2 microglobulin, and CA 125 II, (ii) calculating a biomarker score
from the results of step (i); (iii) comparing the biomarker score to a
predetermined biomarker score cutoff value; and (iv) identifying the
individual as being at risk for having ovarian cancer when the amount of
IL-6 is greater than the IL-6 cutoff value and the biomarker score is
greater than the biomarker score cutoff value, and identifying the
individual as not at risk for having ovarian cancer when either or both
of the amount of IL-6 is less than the IL-6 cutoff value and the
biomarker score is less than the biomarker score cutoff value.
7. The method of claim 6, wherein the amount of three or more biomarkers
selected from the group consisting of transthyretin, apolipoprotein A1,
transferrin, .beta.-2 microglobulin, and CA 125 II are measured and used
to calculate the biomarker score.
8. The method of claim 6, wherein the amount of four or more biomarkers
selected from the group consisting of transthyretin, apolipoprotein A1,
transferrin, .beta.-2 microglobulin, and CA 125 II are measured and used
to calculate the biomarker score.
9. The method of claim 6, wherein the amount of transthyretin,
apolipoprotein A1, transferrin, .beta.-2 microglobulin, and CA 125 II are
measured and used to calculate the biomarker score.
10. The method of any one of claims 1-9, wherein the subject is a
post-menopausal woman.
11. The method of any one of claims 1-9, wherein the subject is a
pre-menopausal woman.
12. The method of any one of claims 1-11, wherein the cutoff value is
determined by a classification algorithm.
13. The method of claim 12, wherein the classification algorithm is a
linear regression formula.
14. The method of claim 13, wherein the classification algorithm is the
product of a learning algorithm.
15. The method of claim 14, wherein the learning algorithm is trained on
biomarker levels from known malignant ovarian cancer samples.
16. The method of any one of claims 1-15, wherein the amount of IL-6 and
the one or more biomarkers are measured by one or more method selected
from the group consisting of immunonephelometry,
electrochemiluminescence, and ELISA.
17. The method of claim 16 wherein the IL-6 is measured by ELISA.
18. The method of claim 16 or 17 wherein transthyretin, apolipoprotein
A1, .beta.-2 microglobulin, and transferrin are measured by the method of
immunonephelometry.
19. The method of any one of claims 16-18 wherein CA 125 II is measured
by the method of electrochemiluminescence.
Description
FIELD OF THE INVENTION
[0001] The invention relates to medically useful assays and methods for
the diagnosis of ovarian cancer.
BACKGROUND OF THE INVENTION
[0002] Ovarian cancer is among the most lethal gynecologic malignancies in
developed countries. Annually, in the United States alone, approximately
23,000 women are diagnosed with the disease and almost 14,000 women die
from it. (Jamal et al., CA Cancer J. Clin., 52:23-47 (2002)). Despite
progress in cancer therapy, ovarian cancer mortality has remained
virtually unchanged over the past two decades. Given the steep survival
gradient relative to the stage at which the disease is diagnosed, early
detection remains the most important factor in improving long-term
survival of ovarian cancer patients.
[0003] The identification of tumor markers suitable for the early
detection and diagnosis of cancer holds great promise to improve the
clinical outcome of patients. It is especially important for patients
presenting with vague or no symptoms or with tumors that are relatively
inaccessible to physical examination. As more tumor biomarkers are
discovered, tests can be modified to provide increased sensitivity and
specificity based on the detection of such tumor markers.
[0004] The poor prognosis of ovarian cancer diagnosed at late stages, the
cost and risk associated with confirmatory diagnostic procedures, and its
relatively low prevalence in the general population together pose
extremely stringent requirements on the sensitivity and specificity of a
test for it to be used for screening for ovarian cancer in the general
population.
[0005] Thus, it is desirable to have a reliable and accurate method of
determining the ovarian cancer status in patients, the results of which
can then be used to manage patient treatment.
SUMMARY OF THE INVENTION
[0006] The instant invention is based on the discovery that interleukin 6
(IL-6) can be used as a biomarker to diagnose ovarian cancer or to assess
the risk (i.e., the likelihood) of an individual to develop ovarian
cancer.
[0007] In one aspect, the invention provides a method for diagnosing or
identifying the risk of an individual for having ovarian cancer
comprising: (a) measuring, in a biological sample from the subject, the
amount of IL-6; (b) comparing the amount of IL-6 measured in step (a) to
a predetermined IL-6 cutoff value; and (c) identifying the individual as
identifying the individual as being at risk for having (or having)
ovarian cancer when the amount of IL-6 is greater than the IL-6 cutoff
value, and identifying the individual as not at risk for having (or
having) ovarian cancer when the amount of IL-6 is less than the IL-6
cutoff value.
[0008] The term "subject," refer to a patient, e.g., female human, who
want to establish ovarian cancer status. The subjects may be women who
have been determined to have a high risk of ovarian cancer based on their
family history. Other patients include women who have ovarian cancer and
the test is being used to determine the effectiveness of therapy or
treatment they are receiving. Also, patients may include healthy women
who are having a test as part of a routine examination, or to establish
baseline levels of the biomarkers. Samples may be collected from women
who have been diagnosed with ovarian cancer and received treatment to
eliminate the cancer, or perhaps are in remission. In one embodiment, the
subject is a post-menopausal woman. In another embodiment, the subject is
a pre-menopausal woman.
[0009] IL-6 refers to a protein or DNA sequence encoded by the IL-6 gene.
The following NCBI accession numbers are associated with human IL-6
protein sequence: P05231.1, NP 000591.1 and AAH15511.1. The NCBI
accession number NM 000600.3 describes the human mRNA sequence of this
gene. Each of these NCBI accession number references and the sequence
associated with each accession number is herein incorporated by reference
in its entirety.
[0010] The term "cutoff value" refers to a predetermined numerical value
that describes the value that demarcates the line between two different
diagnoses. For example, in ovarian cancer, the IL-6 cutoff value can be a
numerical value in which any value determined above such cutoff is
considered to be derived from a patient considered as being at risk or,
alternatively, being at increased risk for having ovarian cancer and any
value determined below such cutoff is considered to be derived from a
patient considered as not being at risk or, alternatively, being at low
risk for having ovarian cancer. In one embodiment, determined values
above the cutoff value indicate a diagnosis of malignant ovarian cancer
and determined values below the cutoff value indicate no malignant
ovarian cancer and/or benign tumors. The cutoff value may have units or
be unit less. In one embodiment, the predetermined cutoff value is
derived from a measurement of the amount of IL-6 in one or more subjects
that do not have ovarian cancer. In a further embodiment, the IL-6 cutoff
value is about 5 pg/mL Alternatively, the IL-6 cutoff value is about 3.5
pg/mL, about 4 pg/mL, about 4.5 pg/mL, about 5.5 pg/mL, about 6 pg/mL,
about 6.5 pg/mL, about 7 pg/mL, about 8 pg/mL, about 8.1 pg/mL, or about
8.5 pg/mL. The cutoff value may be determined experimentally or
mathematically. Such methods for determining a cutoff value
experimentally and mathematically are described herein.
[0011] In one embodiment, the method further comprises (i) measuring, in
the biological sample, the amount of a biomarker selected from the group
consisting of transthyretin, apolipoprotein A1, transferrin, .beta.-2
microglobulin, and CA 125 II, (ii) comparing the amount of the biomarker
measured in step (i) to a predetermined biomarker cutoff value; and (iii)
identifying the individual as being at risk for having ovarian cancer
when the amount of IL-6 is greater than the IL-6 cutoff value and the
amount of the biomarker is greater than the biomarker cutoff value, and
identifying the identifying the individual as not at risk for having
ovarian cancer when either or both of the amount of IL-6 is less than the
IL-6 cutoff value and the amount of the biomarker is less than the
biomarker cutoff value.
[0012] In another embodiment, the method further comprises: (i) measuring,
in the biological sample, the amount of two or more biomarkers selected
from the group consisting of transthyretin, apolipoprotein A1,
transferrin, .beta.-2 microglobulin, and CA 125 II, (ii) calculating a
biomarker score from the results of step (i); (iii) comparing the
biomarker score to a predetermined biomarker score cutoff value; and (iv)
identifying the individual as being at risk for having ovarian cancer
when the amount of IL-6 is greater than the IL-6 cutoff value and the
biomarker score is greater than the biomarker score cutoff value, and
identifying the individual as not at risk for having ovarian cancer when
either or both of the amount of IL-6 is less than the IL-6 cutoff value
and the biomarker score is less than the biomarker score cutoff value. In
one embodiment, the amount of three or more biomarkers selected from the
group consisting of transthyretin, apolipoprotein A1, transferrin,
.beta.-2 microglobulin, and CA 125 II are measured and used to calculate
the biomarker score. In another embodiment, he amount of four or more
biomarkers selected from the group consisting of transthyretin,
apolipoprotein A1, transferrin, .beta.-2 microglobulin, and CA 125 II are
measured and used to calculate the biomarker score. In one embodiment,
the amount of transthyretin, apolipoprotein A1, transferrin, .beta.-2
microglobulin, and CA 125 II are measured and used to calculate the
biomarker score. In a related embodiment, the biomarker score for
transthyretin, apolipoprotein A1, transferrin, .beta.-2 microglobulin,
and CA 125 II is determined from an OVA1 test. In a further embodiment,
the biomarker score cutoff value is about 5, or alternatively, about 4,
or about 4.5, or about 5.5, or about 6, or about 6.5, or about 7, or
about 7.5, or about 8, or about 8.5. In one embodiment, the biomarker
score cutoff value is about 8.1 and the IL-6 cutoff value is 5.0 pg/mL.
[0013] The terms "transthyretin" or "TTR" refers to a protein or DNA
sequence encoded by the TTR gene. The following NCBI accession numbers
are associated with human TTR protein sequence: AAD14937.2, P02766.1,
AAB36045.1, AAD14098.1, ABI63351.1, ABI63345.1, CAA42087.1,
NP.sub.--000362.1 and AAD45014.1. The NCBI accession number
NM.sub.--000371.3 describes the human mRNA sequence of this gene. Each of
these NCBI accession number references and the sequence associated with
each accession number is herein incorporated by reference in its
entirety.
[0014] The terms "apolipoprotein A1" or "ApoA1" refers to a protein or DNA
sequence encoded by the APOA1 gene. The following NCBI accession numbers
are associated with the human ApoA1 protein sequence: CAA00975.1,
P02647.1, NP.sub.--000030.1, AAS68227.1, ACA05936.1, ACA05935.1,
ACA05934.1, ACA05933.1 and ACA05932.1. The NCBI accession number
NM.sub.--000039.1 describes the human mRNA sequence of this gene. Each of
these NCBI accession number references and the sequence associated with
each accession number is herein incorporated by reference in its
entirety.
[0015] The terms "transferrin" or "TF" refers to a protein or DNA sequence
encoded by the TF gene. The following NCBI accession numbers are
associated with the human transferrin protein sequence: NP.sub.--001054,
NP.sub.--054830, AAB22049.1, AAB97880.1, AAA61141.1, and ABI97197.1. The
NCBI accession numbers NM.sub.--001063.3 and NM.sub.--014111 describe the
human mRNA sequence of this gene. Each of these NCBI accession number
references and the sequence associated with each accession number is
herein incorporated by reference in its entirety.
[0016] The terms ".beta.-2 microglobulin" or "B2M" refers to a protein or
DNA sequence encoded by the B2M gene. The following NCBI accession
numbers are associated with the human B2M sequence: NP.sub.--004039.1
(protein) and NM.sub.--004048.2 (mRNA). Each of these NCBI accession
number references and the sequence associated with each accession number
is herein incorporated by reference in its entirety.
[0017] The terms "CA 125 II" "mucin 16" or "MUC16" refer to a protein that
in humans is encoded by the MUC16 gene. The following NCBI accession
numbers are associated with the human MUC16 protein sequence
NP.sub.--078966.2 (protein) and NM.sub.--024690.2 (mRNA). Each of these
NCBI accession number references and the sequence associated with each
accession number is herein incorporated by reference in its entirety.
[0018] The term "diagnose" as used herein refers to the act or process of
identifying or determining a disease or condition in a mammal or the
cause of a disease or condition by the evaluation of the signs and
symptoms of the disease or disorder. Usually, a diagnosis of a disease or
disorder is based on the evaluation of one or more clinical factors
and/or symptoms that are indicative of the disease. That is, a diagnosis
can be made based on the presence, absence or amount of a factor which is
indicative of presence or absence of the disease or condition. Each
factor or symptom that is considered to be indicative for the diagnosis
of a particular disease does not need be exclusively related to the
particular disease; i.e. there may be differential diagnoses that can be
inferred from a diagnostic factor or symptom. Likewise, there may be
instances where a factor or symptom that is indicative of a particular
disease is present in an individual that does not have the particular
disease.
[0019] All numerical designations, e.g., pH, temperature, time,
concentration, and molecular weight, including ranges, are approximations
which are varied (+) or (-) by increments of 1.0 or 0.1, as appropriate
or alternatively by a variation of +/-15%, or alternatively 10% or
alternatively 5% or alternatively 2%. It is to be understood, although
not always explicitly stated, that all numerical designations are
preceded by the term "about". It also is to be understood, although not
always explicitly stated, that the reagents described herein are merely
exemplary and that equivalents of such are known in the art.
[0020] As used in the specification and claims, the singular form "a",
"an" and "the" include plural references unless the context clearly
dictates otherwise. For example, the term "a polypeptide" includes a
plurality of polypeptides, including mixtures thereof.
[0021] As used herein, the term "comprising" is intended to mean that the
compositions and methods include the recited elements, but do not exclude
others. "Consisting essentially of" when used to define compositions and
methods, shall mean excluding other elements of any essential
significance to the combination for the intended use. Thus, a composition
consisting essentially of the elements as defined herein would not
exclude trace contaminants from the isolation and purification method and
pharmaceutically acceptable carriers, such as phosphate buffered saline,
preservatives, and the like. "Consisting of" shall mean excluding more
than trace elements of other ingredients and substantial method steps for
administering the compositions of this invention. Embodiments defined by
each of these transition terms are within the scope of this invention.
[0022] Unless defined otherwise, all technical and scientific terms used
herein have the same meanings as commonly understood by one of ordinary
skill in the art to which this invention belongs.
DETAILED DESCRIPTION OF THE INVENTION
[0023] This invention is predicated on the finding that determining the
amount of IL-6, either alone or in combination with other biomarkers, can
be used to diagnose ovarian cancer.
[0024] Sample Preparation
[0025] Provided herein are methods of using the information obtained
through analysis of the amount of certain biomarkers in biological
samples of acellular biological sample or cell-containing samples. Test
samples may be obtained from an individual or patient. Methods of
obtaining test samples are well-known to those of skill in the art and
include, but are not limited to, aspirations or drawing of blood or other
fluids. Samples may include, but are not limited to, whole blood, serum,
plasma, saliva, urine, and amniotic fluid. In one embodiment, the
biological sample is serum or plasma.
[0026] In embodiments in which the amount of the biomarker will be
determined using an acellular body fluid, the test sample obtained from a
person may be a cell-containing liquid or an acellular body fluid (e.g.,
plasma or serum). In some embodiments in which the test sample contains
cells, the cells may be removed from the liquid portion of the sample by
methods known in the art (e.g., centrifugation) to yield acellular body
fluid for the determination of the amount of certain biomarkers described
herein.
[0027] In other embodiments, the amount of the biomarker can be determined
using a cell-containing sample. In these embodiments the cell-containing
sample includes, but is not limited to, blood, urine, organ, and tissue
samples (e.g., biopsy). Cell lysis may be accomplished by standard
procedures. In certain preferred embodiments, the cell-containing sample
is a whole blood cell lysate. In certain other embodiments, the
cell-containing sample is a white blood cell lysate. Methods for
obtaining white blood cells from blood are known in the art (Rickwood et
al., Anal. Biochem. 123:23-31 (1982); Fotino et al., Ann. Clin. Lab. Sci.
1:131 (1971)). Commercial products useful for cell separation include
without limitation Ficoll-Paque (Pharmacia Biotech) and NycoPrep
(Nycomed).
[0028] Measuring Biomarkers in a Biological Sample
[0029] Aspects of this invention relate to the detection and
quantification of certain biomarkers in a sample. Suitable biophysical or
biomolecular detection methods for qualitatively and quantitatively
detecting a biomarker comprise any suitable method known in the art. Such
methods include, without being limited thereto, methods as applied for
qualitative or quantitative assays such as, for example, electrochemical
methods (voltametry and amperometry techniques), atomic force microscopy,
radio frequency methods, e.g., multipolar resonance spectroscopy,
Enzyme-linked Immunosorbent Assay (ELISA), ELISPOT-Assay, Mass
spectrometry, Western-Blot or Immunoassays. Such methods may comprise
optical, radioactive, chromatographic methods, fluorescence detection
methods, radioactivity detection methods, Coomassie-Blue staining, Silver
staining or other protein staining methods, electron microscopy methods,
methods for staining tissue sections by immunohistochemistry or by direct
or indirect immunofluorescence, etc. Also included are methods that
measure the amount of biomarker by measuring the amount of DNA. Such
methods include real-time PCR, reverse transcriptase-PCR, Southern blot,
and the like.
[0030] Immunoassays, such as an ELISA are commonly used for the detection
of biomarkers in a biological sample. In one example of an ELISA, the
antibodies specific for the biomarker are immobilized on a selected
surface, such as a well in a polystyrene microtiter plate, dipstick, or
column support. Then, a test composition suspected of containing the
desired biomarker, such as a biological sample, is added to the wells.
After binding and washing to remove non specifically bound immune
complexes, the bound biomarker may be detected. Detection is generally
achieved by the addition of another antibody, specific for the desired
biomarker that is linked to a detectable label. This type of ELISA is
known as a "sandwich ELISA." Detection also may be achieved by the
addition of a second antibody specific for the desired biomarker,
followed by the addition of a third antibody that has binding affinity
for the second antibody, with the third antibody being linked to a
detectable label. Variations on ELISA techniques are known to those of
skill in the art. In one embodiment, the amount of IL-6 is determined
using an ELISA assay. In a related embodiment, the ELISA assay used to
determine the IL-6 is a sandwich ELISA assay.
[0031] As used herein, the term "label" intends a directly or indirectly
detectable compound or composition that is conjugated directly or
indirectly to the composition to be detected, for example, N-terminal
histadine tags (N-His), magnetically active isotopes, e.g., .sup.115Sn,
.sup.117Sn and .sup.119Sn, a non-radioactive isotopes such as .sup.13C
and .sup.15N, polynucleotide or protein such as an antibody so as to
generate a "labeled" composition. The term also includes sequences
conjugated to the polynucleotide that will provide a signal upon
expression of the inserted sequences, such as green fluorescent protein
(GFP) and the like. The label may be detectable by itself (e.g.
radioisotope labels or fluorescent labels) or, in the case of an
enzymatic label, may catalyze chemical alteration of a substrate compound
or composition which is detectable. The labels can be suitable for small
scale detection or more suitable for high-throughput screening. As such,
suitable labels include, but are not limited to magnetically active
isotopes, non-radioactive isotopes, radioisotopes, fluorochromes,
chemiluminescent compounds, dyes, and proteins, including enzymes. The
label may be simply detected or it may be quantified. A response that is
simply detected generally comprises a response whose existence merely is
confirmed, whereas a response that is quantified generally comprises a
response having a quantifiable (e.g., numerically reportable) value such
as an intensity, polarization, and/or other property. In luminescence or
fluorescence assays, the detectable response may be generated directly
using a luminophore or fluorophore associated with an assay component
actually involved in binding, or indirectly using a luminophore or
fluorophore associated with another (e.g., reporter or indicator)
component. Examples of luminescent labels that produce signals include,
but are not limited to bioluminescence and chemiluminescence. Detectable
luminescence response generally comprises a change in, or an occurrence
of, a luminescence signal. Suitable methods and luminophores for
luminescently labeling assay components are known in the art and
described in, for example, Haugland, Richard P. (1996) Handbook of
Fluorescent Probes and Research Chemicals (6.sup.th ed.). Examples of
luminescent probes include, but are not limited to, aequorin and
luciferases.
[0032] Competition ELISAs are assays in which test samples compete for
binding with known amounts of labeled proteins. The amount of reactive
species in the unknown sample is determined by mixing the sample with the
known labeled species before or during incubation with coated wells. The
presence of reactive species in the sample acts to reduce the amount of
labeled species available for binding to the well and thus reduces the
ultimate signal. Irrespective of the format employed, ELISAs have certain
features in common, such as coating, incubating or binding, washing to
remove non specifically bound species, and detecting the bound immune
complexes.
[0033] Antibodies may also be linked to a solid support, such as in the
form of plate, beads, dipstick, membrane, or column matrix, and the
sample to be analyzed is applied to the immobilized antigen or antibody.
In coating a plate with either antigen or antibody, one will generally
incubate the wells of the plate with a solution of antibody, either
overnight or for a specified period. The wells of the plate will then be
washed to remove incompletely-adsorbed material. Any remaining available
surfaces of the wells are then "coated" with a nonspecific protein that
is antigenically neutral with regard to the test antisera. These include
bovine serum albumin (BSA), casein, and solutions of milk powder. The
coating allows for blocking of nonspecific adsorption sites on the
immobilizing surface and thus reduces the background caused by
nonspecific binding of antisera onto the surface.
[0034] In the method of the present invention for detecting the presence
of at least one biomarker in a sample a quantitative determination can be
carried out. "Quantitative determination" in the context of the inventive
method is to be understood as any method for determination of an antibody
or proteins or peptides, protein fragments, variants or epitopes thereof,
known by a skilled person suitable for quantifying the amount of a
autoantibody or a secondary antibody, in a sample. As an example, the
inventive method may be carried out with a test sample as a concurrent
standard, containing a defined amount of a biomarker, and in parallel
with a second sample, which is derived from a patient and contains an
unknown amount of a biomarker to be determined against. A comparison of
the defined amount of the biomarker in the test sample with the amount of
the biomarker in the second sample will allow a precise determination of
the amount of biomarker in the second sample. A concurrent standard may
be applied either parallel to carrying out the inventive method or, for
example, prior to said method, by preparing a standard curve, which may
be used in the subsequent quantification.
[0035] In one embodiment, the amount of IL-6 and the one or more
biomarkers are measured by one or more methods selected from the group
consisting of immunonephelometry, electrochemiluminescence, and ELISA.
Immunonephelometry is a technique used to determine levels of antibodies
or antibody/antigen complexes in a sample. It is performed by measuring
the turbidity in a water sample by passing light through the sample being
measured. In immunonephelometry the measurement is made by measuring the
light passed through a sample at an angle. This technique is widely used
in clinical laboratories because it is relatively easily automated. It is
based on the principle that a dilute suspension of small particles will
scatter light (usually a laser) passed through it rather than simply
absorbing it. The amount of scatter is determined by collecting the light
at an angle (usually at 30 and 90 degrees). Antibody and the antigen
(e.g. biomarker) are mixed in concentrations such that only small
aggregates are formed that do not quickly settle to the bottom. The
amount of light scatter is measured and compared to the amount of scatter
from known mixtures. The amount of the unknown is determined from a
standard curve.
[0036] Immunonephelometry is typically performed with antibody as the
reagent and the patient antigen (or biomarker) as the unknown. In the
Immunology Medical Lab, two types of tests can be run: "end point
immunonephelometry" and "kinetic (rate) immunonephelometry". End point
immunonephelometry tests are run by allowing the antibody/antigen
reaction to run through to completion (until all of the present reagent
antibodies and the present patient sample antigens that can aggregate
have done so and no more complexes can form). Unfortunately, the large
particles will fall out of the solution and cause a false scatter
reading, thus kinetic immunonephelometry was devised. In kinetic
immunonephelometry, the rate of scatter is measured right after the
reagent is added. As long as the reagent is constant the rate of change
can be seen as directly related to the amount of antigen or biomarker
present.
[0037] In yet another embodiment, the method includes determining the
amount of the biomarker by electrochemiluminesence. An
electrochemiluminesence immunoassay "ECLIA" is an assay in which a
biomarker bound to labeled antibodies is coupled to microparticles. The
microparticles are magnetically captured onto the surface of the
electrode. Application of a voltage to the electrode induces a
chemiluminescent emission which is measured by a photomultiplier. In one
embodiment, CA 125 II is measured by the method of
electrochemiluminescence.
[0038] Determining the Cutoff Value
[0039] The biomarkers of the invention can be used in diagnostic tests to
indicate whether a patient is at risk or has a high risk of having
ovarian cancer. Such methods can be useful for diagnosing the risk of or
increased risk of ovarian cancer. Such diagnoses can include, for
example, risk of or a high risk of disease (e.g., ovarian cancer
(malignant) versus ovarian cancer of low malignant potential versus
benign ovarian disease versus other malignant conditions), the risk of
developing disease, the stage of the disease, the progress of disease
(e.g., progress of disease or remission of disease over time) and the
effectiveness or response to treatment of disease. Based on this
diagnosis, further procedures may be indicated, including additional
diagnostic tests or therapeutic procedures or regimens.
[0040] The correlation of test results with ovarian cancer status can be
done by applying a classification algorithm of some kind to the results
to generate the status. The classification algorithm may be as simple as
determining whether or not the amount of a given biomarker measured is
above or below a particular cutoff number. When multiple biomarkers are
used, the classification algorithm may be a linear regression formula.
Alternatively, the classification algorithm may be the product of any of
a number of learning algorithms.
[0041] Classification models can be formed using any suitable statistical
classification (or "learning") method that attempts to segregate bodies
of data into classes based on objective parameters present in the data.
Classification methods may be either supervised or unsupervised. Examples
of supervised and unsupervised classification processes are described in
Jain, "Statistical Pattern Recognition: A Review," IEEE Transactions on
Pattern Analysis and Machine Intelligence, Vol. 22, No. 1, January 2000,
the teachings of which are incorporated by reference.
[0042] In supervised classification, training data containing examples of
known categories are presented to a learning mechanism, which learns one
or more sets of relationships that define each of the known classes. New
data may then be applied to the learning mechanism, which then classifies
the new data using the learned relationships. Examples of supervised
classification processes include linear regression processes (e.g.,
multiple linear regression (LR), partial least squares (PLS) regression
and principal components regression (PCR)), binary decision trees (e.g.,
recursive partitioning processes such as CART--classification and
regression trees), artificial neural networks such as back propagation
networks, discriminant analyses (e.g., Bayesian classifier or Fischer
analysis), logistic classifiers, and support vector classifiers (support
vector machines).
[0043] One supervised classification method is a recursive partitioning
process. Recursive partitioning processes use recursive partitioning
trees to classify data derived from unknown samples. Further details
about recursive partitioning processes are provided in U.S. patent
application No. 2002/0138208 A1 to Paulse et al., "Method for Analyzing
Mass Spectra."
[0044] In other embodiments, the classification models that are created
can be formed using unsupervised learning methods. Unsupervised
classification attempts to learn classifications based on similarities in
the training data set, without pre-classifying the spectra from which the
training data set was derived. Unsupervised learning methods include
cluster analyses. A cluster analysis attempts to divide the data into
"clusters" or groups that ideally should have members that are very
similar to each other, and very dissimilar to members of other clusters.
Similarity is then measured using some distance metric, which measures
the distance between data items, and clusters together data items that
are closer to each other. Clustering techniques include the MacQueen's
K-means algorithm and the Kohonen's Self-Organizing Map algorithm.
[0045] Learning algorithms asserted for use in classifying biological
information are described, for example, in PCT International Publication
No. WO 01/31580 (Barnhill et al., "Methods and Devices for Identifying
Patterns in Biological Systems and Methods of Use Thereof"), U.S. patent
application No. 2002/0193950 A1 (Gavin et al., "Method or analyzing mass
spectra"), U.S. patent application No. 2003/0004402 A1 (Hitt et al.,
"Process for Discriminating Between Biological States Based on Hidden
Patterns from Biological Data"), and U.S. patent application No.
2003/0055615 A1 (Zhang et al., "Systems and Methods for Processing
Biological Expression Data").
[0046] The classification models can be formed on and used on any suitable
digital computer. Suitable digital computers include micro, mini, or
large computers using any standard or specialized operating system, such
as a Unix, Windows.TM., or Linux.TM., based operating system. The digital
computer that is used may be physically separate from the device that is
used to create the data of interest, or it may be coupled to such device.
[0047] The training data set and the classification models according to
embodiments of the invention can be embodied by computer code that is
executed or used by a digital computer. The computer code can be stored
on any suitable computer readable media including optical or magnetic
disks, sticks, tapes, etc., and can be written in any suitable computer
programming language including C, C++, visual basic, etc.
[0048] The learning algorithms described above are useful both for
developing classification algorithms for the biomarkers already
discovered, or for finding new biomarkers for ovarian cancer. The
classification algorithms, in turn, form the base for diagnostic tests by
providing diagnostic values (e.g., cut-off points) for biomarkers used
singly or in combination. In one embodiment, the classification algorithm
is the product of a learning algorithm. In a related embodiment, the
learning algorithm is trained on biomarker levels from known malignant
ovarian cancer samples.
[0049] In the case of complex classification algorithms, it may be
necessary to perform the algorithm on the data, thereby determining the
classification, using a computer, e.g., a programmable digital computer.
In either case, one can then record the status on tangible medium, for
example, in computer-readable format such as a memory drive or disk or
simply printed on paper. The result also could be reported on a computer
screen.
[0050] In one embodiment, classification algorithms are used to determine
a cutoff value from the measured amounts of biomarkers selected from the
group consisting of transthyretin, apolipoprotein A1, transferrin,
.beta.-2 microglobulin, and CA 125 II. In another embodiment, the
classification algorithm is a linear regression formula.
[0051] Diagnosis of Ovarian Cancer
[0052] Methods described herein are useful for the diagnosis of ovarian
cancer. They can also be combined with or supplement traditional methods
used to diagnose ovarian cancer. Other methods include a physical
examination (including a pelvic examination), a blood test (for various
biomarkers), and transvaginal ultrasound. The diagnosis is traditionally
confirmed with surgery to inspect the abdominal cavity, take biopsies
(tissue samples for microscopic analysis) and look for cancer cells in
the abdominal fluid.
[0053] Ovarian cancer at its early stages (I/II) is difficult to diagnose
until it spreads and advances to later stages (III/IV). This is because
most symptoms are non-specific and thus of little use in diagnosis. The
serum BHCG level is typically measured in any female in whom pregnancy is
a possibility. In addition, serum alpha-fetoprotein (AFP) and lactate
dehydrogenase (LDH) is typically measured in young girls and adolescents
with suspected ovarian tumors because the younger the patient, the
greater the likelihood of a malignant germ cell tumor.
[0054] The OVA1 FDA-approved test (available commercially from Quest
Diagnostics, Inc.) tests for the biomarkers transthyretin, apolipoprotein
A1, transferrin, .beta.-2 microglobulin, and CA 125 II and uses an
algorithm to indicate the probability of malignancy of an ovarian mass
based on the test results of these five biomarkers. It is not a screening
or standalone test but when used in conjunction with a standard
pre-surgical evaluation this test can be used to:
[0055] assess the likelihood that an ovarian mass is malignant before its
removed;
[0056] help to identify patients for referral to a gynecologic oncologist
and
[0057] may produce improved patient outcomes.
[0058] In the presence of ovarian serous carcinoma, CA 125 II will
increase as will beta 2 microglobulin Apolipoprotein A1, pre-albumin
(transthyretin) and transferrin will decrease. In large increases of
CA125 II, the score will be weighted in favor of showing a high risk of
malignancy. Other carcinomas of ovarian origin or metastatic origin will
likely increase the OVA1 score to above the cutoff levels.
[0059] A pelvic examination and imaging including CT scan and
trans-vaginal ultrasound are essential. Physical examination may reveal
increased abdominal girth and/or ascites (fluid within the abdominal
cavity). Pelvic examination may reveal an ovarian or abdominal mass. The
pelvic examination can include a rectovaginal component for better
palpation of the ovaries. For very young patients, magnetic resonance
imaging may be preferred to rectal and vaginal examination.
[0060] To definitively diagnose ovarian cancer, a surgical procedure to
take a look into the abdomen is usually performed. This can be an open
procedure (laparotomy, incision through the abdominal wall) or keyhole
surgery (laparoscopy). During this procedure, suspicious areas will be
removed and sent for microscopic analysis. Fluid from the abdominal
cavity can also be analysed for cancerous cells. If there is cancer, this
procedure can also determine its spread (which is a form of tumor
staging).
EXAMPLE 1
IL-6 High Sensitivity ELISA
[0061] This assay employs the quantitative sandwich enzyme immunoassay
technique. The wells of a microplate are pre coated with an IL-6 specific
monoclonal antibody. When pipetted into the wells, the IL-6 present in
any of the standards, controls, and samples is immobilized by the
monoclonal antibody. After washing away any unbound substances, an enzyme
linked polyclonal antibody specific to IL-6 is added to the wells.
Following a wash to remove any unbound enzyme-antibody, a substrate
solution is added to the wells. After an incubation period, an amplifier
solution is added to develop a colored signal. The intensity of the
color, which is proportional to the amount of IL-6 bound in the initial
step, is quantified by a plate reader.
[0062] Specimen Requirements. Cytokine levels may demonstrate diurnal
variation. Recommend cytokine levels be determined at the same time of
day for improved longitudinal comparison.
[0063] Specimen Type & Handling. Specimen types useful in this IL-6 ELISA
include but are not limited to Serum, Plasma, Plasma with added EDTA,
human breast milk, and vaginal swabs. About 1 mL of a sample is collected
from the subject and either analyzed or frozen for future analysis.
[0064] Reagent preparation. A microtest strip (96 well polystyrene
microplate coated with mouse monoclonal antibody against IL-6) is allowed
to equilibrate to room temperature (18-26.degree. C.). Next, the wash
buffer is prepared. Concentrated wash buffer solution (100 mL of
10.times. solution of buffered surfactant with preservatives) is warmed
to room temperature and mixed gently to allow for the crystals to
dissolve. lx wash buffer is made by mixing 100 mL of the 10.times.
solution with 900 mL DI-water (Nerl or equivalent). The 10 pg/ml standard
is prepared by adding 5 mL of RD6-11 (21 mL of a buffered protein base
with preservatives) to lyophilized IL-6 (50 pg lyophilized recombinant
human IL-6) at least 15 minutes prior to use. The standard is allowed to
sit for a minimum of 15 minutes with gentle agitation prior to making
dilutions. The substrate is prepared by reconstituting lyophilized
substrate (lyophilized NADPH with stabilizers) with 6 mL of Substrate
Diluent (7 mL of buffered solution with stabilizers) at least 10 minutes
before use. The substrate is capped and thoroughly mixed. The amplifier
solution is prepared by reconstituting lyophilized Amplifier (Lyophilized
amplifier enzymes with stabilizers) with 6 mL of Amplifier Diluent (7 mL
of buffered solution containing INT-violet with stabilizers) at least 10
minutes before use. The vial is capped and mixed thoroughly. Human IL-6
at high, medium, and low concentrations is used as quality control
standards.
[0065] Preparation of IL-6 Standard Curve. The following concentrations of
standard are prepared from the 10 pg/ml standard: 0.0 pg/mL (calibrator
diluent RD6-11 only), 0.156 pg/mL, 0.312 pg/mL, 0.625 pg/mL, 1.25 pg/mL,
2.5 pg/mL, 5.0 pg/mL, and 10 pg/mL. The eight standards are run in
duplicate with every assay set-up. Up to 4 standard curve singlicate ODs
(or 2 non-consecutive standard points) can be rejected if they exceed 20%
CV.
[0066] Assay. Patient samples and controls are thawed at room temperature
and samples are mixed. For breast milk samples preparation, only the
aqueous fraction of the breast milk is needed for testing. To obtain
aqueous fraction, breast milk samples are centrifuged at 700 to 720g for
20 min at room temperature and then incubated at 2-8.degree. C. for 5
minutes without disturbing the fatty layer. After 5 minutes in the
refrigerator, using disposable Pasteur pipettes the aqueous fraction is
transferred to another tube without disturbing the fatty layer. For
vaginal swabs sample, the sample is mixed and the swab is removed before
pipetting.
[0067] The microtiter plate is set up with sufficient wells for running
standards and controls in duplicate. 100 .mu.L of the Assay Diluent
RD1-75 (11 mL of a buffered protein base with preservatives) is added to
each well of the microtiter plate. 100 .mu.L of each standard, control,
and patient sample (initial testing for sample is run undiluted) is added
into the appropriate wells. Patient samples can be diluted according to
the following Table:
TABLE-US-00001
Patient Sample Calibrator Diluent
Dilution in .mu.L RD6-11 in .mu.L
1:2 200 200
1:8 100 of 1:2 300
1:32 100 of 1:8 dilution 300
1:256 100 of 1:32 dilution 700
1:1280 100 of 1:256 400
[0068] The plate is covered with the plate sealer and incubated at room
temperature on a plate shaker at 500.+-.50 rpm for 120 minutes. Next, the
plate is washed 6 times, turned upside down and tapped on towels to
remove any of the remaining wash buffer. 200 .mu.L of Conjugate (21 mL of
polyclonal antibody against IL-6, conjugated to alkaline phosphatase,
with preservatives) is added to each well. The plate is then covered and
incubated at room temperature on a plate shaker at 500.+-.50 rpm for 120
minutes. Next, the plate is washed 6 times 50 .mu.L of substrate is added
to each well. The plate is then covered and incubated at room temperature
for 60 minutes. Next, 50 .mu.L of amplifier solution is added to each
well and the plate is covered and incubated at room temperature for 30
minutes. Next, 50 .mu.L of stop solution (6 mL of 2N sulfuric acid) is
added to each well. Plate is then read on Powerwave Plate Reader set at
490 nm with corrections at 650 nm.
[0069] Calculations. The average absorbance values for each set of
duplicate standards, controls, and samples is calculated. The calibration
curve is obtained by plotting the standards' concentrations in pg/mL
versus the corresponding A.sub.490-650. A log/log linear curve fit
subtracting the zero standard (blank) is used. Samples with a
concentration above or equal to the second highest standard and up to the
highest standard will be diluted with Calibrator Diluent RD6-11 and
re-tested at NT, 1:8, 1:32, 1:256 or higher until the OD's are within the
standard curve. The test sample is fit on the curve and the concentration
of IL-6 in the test sample is determined.
[0070] Interleukin 6 (IL-6) may be considered the protypical pleiotrophic
cytokine Human IL-6 is a variably glycosylated 22-27 kDa glycoprotein.
IL-6 is translated as a 212 amino acid (aa) molecule, which incorporated
a 28 aa signal and a 184 aa mature segment. Expression of IL-6 has been
observed in CD8 +T cells, fibroblasts, synoviocytes, adipocytes,
osteoblasts, megakaryocytes, endothelial cells, sympathetic neurons,
cerebral cortex neurons, adrenal medulla chromaffin cells, retinal
pigment cells, mast cells, keratinocytes, Langerhans cells, fetal and
adult astrocytes, neutrophils, monocytes, eosinophils, colonic epithelial
cells, B1 B cells, and most likely pancreatic islet beta cells. The
production of IL-6 is generally correlated to cell activation. IL-6 has
been described as both pro- and anti-inflammatory molecule, a modulator
of bone resorption, a promoter of hematopoiesis, and an inducer of plasma
cell development. In normal individuals the circulating IL-6 found in the
blood is in the range of 1 pg/mL, with slight elevations during the
menstrual cycle, modest elevations during some cancers, and large
elevations following surgery.
EXAMPLE 2
Determining Specificity and Sensitivity of Tests for Ovarian Cancer
[0071] Using assays and methods described herein, the amount of IL-6 was
determined in samples with known ovarian cancer status. The OVA-1 score
was also determined in the same samples. The OVA-1 is a commercially
available test (Vermillion, Inc.) described previously. The specificity
and sensitivity of each test was calculated as follows: Sensitivity=True
Positives/(True Postives+False Negatives); Specificity=True
Negatives/(True Negatives+False Positives).
[0072] The results of these tests and specificity and sensitivity are
tabulated below:
TABLE-US-00002
IL-6
Patients OVA-1 (pg/mL) Diagnosis
Pooled #1 2.3 2.7 Benign
Pooled #2 1.9 3.4 Benign
Pooled #3 2.1 3.7 Benign
Pooled #4 1.7 4.7 Benign
Pooled #5 5.3 9.9 Malignant
Patient 65035811 9.7 1042.0 Malignant ("Ovarian Malignancy
with positive nodes)
Patient 65005473 8.0 1.8 Benign ("Endometrioma of the
ovary")
Patient 65014335 6.9 40.7 Malignant ("Ovarian cancer and
renal cancer")
Patient 65069832 6.3 5.0 Benign ("Hydrosalpinx")
Patient 65087301 8.2 3.4 ("Metastatic esophageal
adenocarcinoma")
Patient 65061954 8.2 5.0 Benign ("Cystadenoma of the
ovary")
Patient 65062186 3.5 2.0 Benign ("Benign hemorrhagic
ovarian cyst")
Patient 65041032 7.4 8.7 Malignant
("Anaplastic carcinoma")
Patient 65050870 9.1 31.4 Malignant ("Carcinomatosis")
Patient 65047450 6.6 2.8 Benign ("No adnexal mass; benign
endometrial biopsy")
Patient 65039328 5.1 0.9 Benign ("Benign ovarian cyst")
Patient 65005240 7.9 7.9 Benign ("No ovarian mass;
adenomyosis")
Patient 65074605 6.3 2.3 Benign ("Clinically benign and lost
to followup")
Sensitivity 100% 83%
Specificity 42% 92%
[0073] OVA-1 cutoffs are: pre-menopausal is about 4.4 and postmenopausal
is about 5.0. IL-6 cutoff is about 5.00 pg/mL.
[0074] Using the same OVA-1 scores and IL-6 amounts, the specificity and
sensitivity was determined with an OVA-1 score greater than 8.1 in the
presence of a normal IL6 (i.e. less than or equal to 5.0 pg/mL) and with
an OVA1-score greater than the current cutoffs (i.e. 4.4/5.0) in the
presence of an elevated IL6 (i.e. greater than 5.0 pg/mL). These criteria
would produce a sensitivity of 100% and specificity of 89%.
[0075] The contents of the articles, patents, and patent applications, and
all other documents and electronically available information mentioned or
cited herein, are hereby incorporated by reference in their entirety to
the same extent as if each individual publication was specifically and
individually indicated to be incorporated by reference. Applicants
reserve the right to physically incorporate into this application any and
all materials and information from any such articles, patents, patent
applications, or other physical and electronic documents.
[0076] The inventions illustratively described herein may suitably be
practiced in the absence of any element or elements, limitation or
limitations, not specifically disclosed herein. Thus, for example, the
terms "comprising", "including," "containing", etc. shall be read
expansively and without limitation. Additionally, the terms and
expressions employed herein have been used as terms of description and
not of limitation, and there is no intention in the use of such terms and
expressions of excluding any equivalents of the features shown and
described or portions thereof, but it is recognized that various
modifications are possible within the scope of the invention claimed.
Thus, it should be understood that although the present invention has
been specifically disclosed by preferred embodiments and optional
features, modification and variation of the inventions embodied therein
herein disclosed may be resorted to by those skilled in the art, and that
such modifications and variations are considered to be within the scope
of this invention.
[0077] The invention has been described broadly and generically herein.
Each of the narrower species and subgeneric groupings falling within the
generic disclosure also form part of the invention. This includes the
generic description of the invention with a proviso or negative
limitation removing any subject matter from the genus, regardless of
whether or not the excised material is specifically recited herein.
[0078] Other embodiments are within the following claims. In addition,
where features or aspects of the invention are described in terms of
Markush groups, those skilled in the art will recognize that the
invention is also thereby described in terms of any individual member or
subgroup of members of the Markush group.
* * * * *