NEW YORK (GenomeWeb) – Researchers associated with Sera Diagnostics this week published a study in the American Journal of Obstetrics and Gynecology detailing the development and validation of the company's proteomic PreTRM test for predicting a woman's risk of preterm delivery.
The study found that the test, which is intended for use in the 19th week of gestation, was able to predict whether a woman would deliver before 37 weeks with 75 percent sensitivity and 74 percent specificity, and an area under the receiver operating curve of .75. It was able to predict delivery before 35 weeks with 100 percent sensitivity and 83 percent specificity and an AUC of .93.
The results, the authors noted, indicate that the test can identify "asymptomatic pregnant women at risk of spontaneous preterm delivery, which may provide utility in identifying women at risk at an early stage of pregnancy to allow for clinical intervention."
The study, named PAPR, for Proteomic Assessment of Preterm Risk, enrolled a total of 5,501 pregnant women between 17 and 28 weeks gestation at 11 sites around the US between 2011 and 2013. Of those, 5,235 remained in the study until their delivery and 4,825 were analyzed (410 were excluded due to being on progesterone therapy for preventing preterm birth).
Of those 4,825 women, 4,292 carried their babies to term while 248 experienced spontaneous preterm birth (285 had medically indicated preterm births and were excluded.) Of these 248 sPTB subjects, 31 were excluded for preanalytic reasons, leaving 217, 86 of which were used in discovery, 50 in verification, and 81 in validation.
Sera used a multiple-reaction monitoring mass spec workflow for all stages of the test development process, starting with 148 candidate protein markers that they ultimately winnowed down to a final panel consisting of two proteins, insulin-like growth factors binding protein 4 (IBP4), and sex-hormone binding globulin (SHBG).
While the results indicate this panel is useful in identifying women at risk of giving preterm birth and showed particularly high accuracy for earlier sPTDs, which, the authors noted, have "the greatest potential for morbidity," the study did have certain limitations.
Specifically, the study was not able to enroll enough women who had previously given preterm birth who were not on progesterone therapy, and therefore the analysis did not cover women with prior sPTDs. Additionally, transvaginal ultrasound cervical length measurements were available for fewer than one-third of subjects, and so it was not possible to determine if such measurements could improve the performance of the PreTRM test, or if the PreTRM test might aid in interpretation of ultrasound measurements.
The researchers also noted that they hoped in the future to study the performance of the test combined with variables like body mass or other medical or demographic characteristics.
Sera rolled out a limited commercial launch of the test this fall, making it available primarily to key opinion leaders who were working with the company on the PAPR study. It is now preparing for a wider launch of the test, which it plans to offer out of its CLIA lab.