Devices and methods for detecting amniotic fluid in vaginal secretions
The present invention relates to a diagnostic method for the detection of small quantities of amniotic fluid in the vagina. More specifically, the invention relates to the detection of PAMG-1 in the vagina using anti-PAMG-1 antibodies.
1. A method for diagnosing rupture of fetal membranes (ROM) with 100% negative predictive value in a pregnant woman using a device comprising a pad region and a test region, the method comprising:
(a) introducing a vaginal fluid sample obtained from the pregnant woman to the pad region of the device, wherein the pad region comprises a first monoclonal antibody that is specific for PAMG-1 protein, wherein the first monoclonal antibody is mobilizable and binds to the PAMG-1 protein when present in the sample to form a PAMG-1 protein/monoclonal antibody complex;
(b) detecting, in the test region of the device, the presence of the PAMG-1 protein/monoclonal antibody complex in the sample, only when the concentration of the PAMG-1 protein in the sample exceeds a predefined detection threshold, wherein the test region comprises a second monoclonal antibody that is specific for the same PAMG-1 protein and is immobilized in the test region, wherein:
(i) the first and second monoclonal antibodies do not cross-react with each other and wherein the first and second PAMG-1-specific monoclonal antibodies are selected from the group consisting of M271, produced by hybridoma N271, deposited with the Russian National Collection of Industrial Microorganisms (VKPM) Depository and assigned accession number VKPM-93; M52, produced by hybridoma N52, deposited with the VKPM and assigned accession number VKPM-92; and M42, produced by hybridoma N42, deposited with the VKPM and assigned accession number VKPM-94; and
(ii) the predefined detection threshold is set at 5 ng/ml, a level that eliminates 100% of false positive results by adjusting the concentration of one or both of the first and second monoclonal antibodies; and
(c) diagnosing ROM with 100% negative predictive value if the PAMG-1 protein is detected in the sample.
2. The method of claim 1 , further comprising diagnosing ROM with at least 99% specificity and 100% sensitivity.
3. The method of claim 1 , further comprising diagnosing ROM with 99% positive predictive value.
4. The method of claim 1 , wherein the pregnant woman is at 20 to 41 weeks' gestation.
5. A method for diagnosing ROM with at least 99% positive predictive value in a pregnant woman using a device comprising a pad region and a test region, the method comprising:
(a) introducing a vaginal fluid sample obtained from the pregnant woman to the pad region of the device, wherein the pad region comprises a first monoclonal antibody that is specific for PAMG-1 protein, wherein the first monoclonal antibody is mobilizable and binds to the PAMG-1 protein when present in the sample to form a PAMG-1 protein/monoclonal antibody complex;
(b) detecting, in the test region of the device, the presence of the PAMG-1 protein/monoclonal antibody complex in the sample, only when the concentration of PAMG-1 in the sample exceeds a predefined detection threshold that is set at a level that reduces false negative results such that at least 99% positive predictive value is achieved, wherein the test region comprises a second monoclonal antibody that is specific for the same PAMG-1 protein and is immobilized in the test region, wherein:
(i) the first and second monoclonal antibodies do not cross-react with each other and wherein the first and second PAMG-1-specific monoclonal antibodies are selected from the group consisting of M271, produced by hybridoma N271, deposited with the Russian National Collection of Industrial Microorganisms (VKPM) Depository and assigned accession number VKPM-93; M52, produced by hybridoma N52, deposited with the VKPM and assigned accession number VKPM-92; and M42, produced by hybridoma N42, deposited with the VKPM and assigned accession number VKPM-94; and
(ii) the predefined detection threshold is set at 5 ng/ml by adjusting the concentration of one or both of the first and second monoclonal antibodies; and
(c) diagnosing ROM with at least 99% positive predictive value if the PAMG-1 protein is detected in the sample.
6. The method of claim 5 , further comprising diagnosing ROM with at least 99% specificity and 100% sensitivity.
7. The method of claim 5 , wherein the pregnant woman is at 20 to 41 weeks' gestation.
8. A method for diagnosing ROM in a pregnant woman with at least 99% specificity and 100% sensitivity using a device comprising a pad region and a test region, the method comprising:
(a) introducing a vaginal fluid sample obtained from the pregnant woman to the pad region of the device, wherein the pad region comprises a first monoclonal antibody that is specific for PAMG-1 protein, wherein the first monoclonal antibody is mobilizable and binds to the PAMG-1 protein when present in the sample to form a PAMG-1 protein/monoclonal antibody complex;
(b) detecting, in the test region of the device, the presence of the PAMG-1 amniotic protein/monoclonal antibody complex in the sample, only when the concentration of the PAMG-1 protein in the sample exceeds a predefined detection threshold, wherein the test region comprises a second monoclonal antibody that is specific for the same PAMG-1 protein and is immobilized in the test region of the device, wherein:
(i) the first and second monoclonal antibodies do not cross-react with each other and wherein the first and second PAMG-1-specific monoclonal antibodies are selected from the group consisting of M271, produced by hybridoma N271, deposited with the Russian National Collection of Industrial Microorganisms (VKPM) Depository and assigned accession number VKPM-93; M52, produced by hybridoma N52, deposited with the VKPM and assigned accession number VKPM-92; and M42, produced by hybridoma N42, deposited with the VKPM and assigned accession number VKPM-94; and
(ii) the predefined detection threshold is set at 5 ng/ml by adjusting the concentration of one or both of the first and second monoclonal antibodies; and
(c) diagnosing ROM with at least 99% specificity and 100% sensitivity if the PAMG-1 protein is detected in the sample.
9. A method for diagnosing ROM with 100% negative predictive value in a pregnant woman using a device comprising a pad region and a test region, the method comprising:
(a) introducing a vaginal fluid sample obtained from the pregnant woman to the pad region of the device, wherein the pad region comprises a first monoclonal antibody that is mobilizable and is specific for PAMG-1 protein;
(b) detecting, in the test region of the device, the presence of the PAMG-1 protein only when the concentration of the PAMG-1 protein in the sample exceeds a predefined detection threshold, wherein the test region comprises a second monoclonal antibody that is specific for the same PAMG-1 protein and is immobilized in the test region; wherein:
(i) the first and second monoclonal antibodies do not cross-react with each other and wherein the first and second PAMG-1-specific monoclonal antibodies are selected from the group consisting of M271, produced by hybridoma N271, deposited with the Russian National Collection of Industrial Microorganisms (VKPM) Depository and assigned accession number VKPM-93; M52, produced by hybridoma N52, deposited with the VKPM and assigned accession number VKPM-92; and M42, produced by hybridoma N42, deposited with the VKPM and assigned accession number VKPM-94; and
(ii) the predefined detection threshold is set at 5 ng/ml, a level that eliminates 100% of false positive results by adjusting the concentration of one or both of the first and second monoclonal antibodies; and
(c) diagnosing ROM with 100% negative predictive value if the PAMG-1 protein is detected in the sample.