[Screening and verification of plasma biomarkers for stable angina pectoris: a differential proteomic analysis].

OBJECTIVE: To compare and analyze the differentially expressed plasma proteome between patients with stable angina pectoris (SAP) and healthy donors to identify the biomarkers for early diagnosis of SAP.

METHODS: Plasma samples from 60 patients with SAP and 60 healthy controls were collected. Twenty samples (100 mL each) randomly selected from each group were pooled and after removing high-abundance proteins from the pooled plasma, two-dimensional gel electrophoresis (2DE) was performed to isolate the total proteins. The protein spots with more than 2 fold changes were selected after 2D analysis using software, and the differentially expressed proteins were identified by MALDI TOF/TOF mass spectrometer. ELISA was performed to detect hemoglobin subunit delta (HBD) levels in 40 randomly selected samples from each group for verification of the results of 2DE.

RESULTS: A total of 7 differentially expressed proteins were found in plasma samples from patients with SAP, including 3 up regulated proteins (serum albumin, hemoglobin subunit alpha and hemoglobin subunit delta,) and 4 down?regulated ones (apolipoprotein L1, apolipoprotein C3, apolipoprotein E and complement C4B). ELISA results showed that HBD level was increased in SAP plasma, which was consistent with the results of 2DE.

CONCLUSION: Patients with SAP have different plasma protein profiles from those of healthy controls, and HBD may serve as a potential specific biomarker for early diagnosis of SAP.