Proteomic identification of candidate plasma biomarkers for preeclampsia in women with pregnancy-induced hypertension

Preeclampsia (PE), a complication of pregnancy, is the leading cause of maternal and perinatal morbidity and mortality and seriously impacts maternal and child health. This study aimed to characterize biomarkers for the early diagnosis of PE. We performed a comparative proteomic analysis on the plasma obtained from PE and healthy pregnant women. We analyzed the plasma samples using two-dimensional differential gel electrophoresis (2D-DIGE) coupled with Ultraflex III, a MALDI-TOF-TOF (matrix-assisted laser desorption/ionization-time-of-flight) mass spectrometer and identified differentially expressed proteins (DEPs). We analyzed the abundance levels of these DEPs by enzyme-linked immunosorbent assay (ELISA) to further confirm their role as putative PE biomarkers. We identified a total of 56 DEPs, of which 48 were down-regulated and 8 were up-regulated in women with PE. The identities of 8 of these DEPs were characterized by mass spectrum analysis, including LG3BP (lectin, galactoside-binding, soluble, 3 binding protein), APOA1 (apolipoprotein A-I), FETUA (alpha-2-HS-glycoprotein), CFAI (complement factor I), CD5L (CD5 antigen-like), K2C6A (keratin, type II cytoskeletal 6A), PON1 (paraoxonase/arylesterase 1) and HP1 (haptoglobin). Finally, the differential expression of these 8 proteins was verified by ELISA. In summary, we applied the 2D-DIGE and Ultraflex III-TOF/TOF platform to identify potential plasma biomarkers of PE. Of these, plasma LG3BP, APOA1, FETUA, CFAI, CD5L, K2C6A, PON1 and HP1 were promising candidates for predicting PE.