492: Plasma proteomic profiles in preterm labor (PTL) and preterm premature rupture of membranes (PPROM)

preterm premature rupture of membranes (PPROM) Joyce Sung, John Whitin, Qing Yang, Ashima Madan, Yasser El-Sayed Stanford University School of Medicine/Lucile Salter Packard Children’s Hospital, Obstetrics & Gynecology, Division of Maternal-Fetal Medicine, Stanford, CA, Stanford University, Pediatrics, Stanford, CA, Hunan Agricultural University, School of Veterinary Medicine, Changsha City, Hunan Province, China, Healthy Start Pediatrics, Pediatrics, Mountain View, CA OBJECTIVE: To compare plasma proteomic profiles of patients presenting with PTL and/or PPROM to those presenting with term labor. STUDY DESIGN: Plasma was prospectively collected from women at the time of presentation with (1) PTL between 24-34 weeks gestation and subsequent preterm delivery, (2) PPROM between 24-34 weeks and preterm delivery, and (3) term labor between 37-42 weeks. Samples were analyzed by surface-enhanced laser desorption/ionization timeof-flight mass spectrometry (SELDI-TOF MS) using ProteinChip arrays. We compared SELDI-TOF MS profiles for PTL vs. term labor; PPROM vs. term labor; PTL PPROM vs. term labor; and PTL vs. PPROM. RESULTS: 8 patients presented with PTL, 7 with PPROM, and 18 with term labor. There were no significant differences in maternal age, race, or education level between the three groups. Mean gestational age at delivery was significantly less in PTL (32.8 weeks) and PPROM (31.9 weeks) patients, when compared to term labor patients (39.1 weeks). A total of 1274 SELDI mass spectra peaks were analyzed. The number of peaks significantly different at p 0.05 using the Mann-Whitney U test ranged from 34-64 for the different comparisons (see table). False Discovery Rate (FDR) analysis was then used to control for multiple hypothesis testing. When analyzing 1274 peaks, 62 peaks would be expected at significance of p 0.05. In addition, for all of the above comparisons, none of the seemingly significantly different peaks met the threshold of validity of a local FDR of 5%. CONCLUSION: No differences in plasma proteomic profiles were seen between PTL, PPROM, and term labor patients at the time of presentation. Possible explanations include: 1) differences exist in other compartments (e.g. amniotic fluid) that are not seen in plasma; 2) both term labor and PTL/PPROM may involve similar proteomic changes, regardless of gestational age at presentation; and 3) the methods used here detect 200 of the most abundant plasma proteins, but differences may exist in less abundant proteins (e.g. cytokines).