SERPINA1 and plasminogen as novel biomarkers in obstetric antiphospholipid syndrome patients.

OBJECTIVES: To explore the potential biomarkers and mechanisms in obstetric antiphospholipid syndrome (OAPS) patients by placental proteomics. METHODS: Among 212 follow-up pregnancy patients based on the Chinese Rheumatism Data Center database (CRDC), we continuously recruited 30 pregnancy patients at the late stage of pregnancy for proteomics study. Fresh placental tissues were collected and 4D label-free technologies were used to analyse the placental proteome in patients. Bioinformatic analysis was applied to identify differentially expressed proteins (DEPs) and crucial pathways. Placental tissues were also stained with haematoxylin and eosin (H & E) for histological analysis. RESULTS: We collected 7 OAPS patients (33.85±1.57 years), 4 SAPS patients (34.25 ± 3.86 years), 8 SLE patients (30.38±2.56 years), and 11 healthy controls (31.45±3.01 years). All patients in the SAPS and OAPS group had adverse pregnancy history. A total of 7040 proteins containing at least one unique peptide were identified. There were 214 DEPs between the healthy group and the OAPS group, of which 82 proteins were upregulated and 132 proteins were downregulated in the OAPS group based on fold change ≥1.5 and p-values ≤0.05. We found that the complement and coagulation pathway played a significant role in OAPS patients. Several key proteins (C1Q, C4b, SERPINA1, plasminogen) highly expressed in placental tissues, that may serve as biomarkers for OAPS patients. CONCLUSIONS: The complement and coagulation pathway and related DEPs (SERPINA1 and plasminogen) were of crucial importance in OAPS patients.