Objective: To investigate the D8/17 antigen expression of patients with rheumatic heart disease (RHD) in Guangdong province and study the antigen's characteristics.
Methods: The level of D8/17 antigen expression on B lymphocytes was determined with flow cytometry assay in 96 RHD patients and 83 unaffected controls. The percentage of B-cells expressing the D8/17 antigen having more than 10% was considered to be positive. D8/17 antigen was extracted by immunoprecipitation, and the antigen characteristics was analyzed by tandem mass spectrometry.
Results: The mean percentage of B-cells expressing the D8/17 antigen was (85.36 ± 15.15)% in the RHD patients and (82.89 ± 4.55)% in the controls, with no significant difference between the two groups (P = 0.436). Moreover, the positive rate of the D8/17 expression was 100% in either the RHD patients or the controls. The molecular weight of D8/17 antigen was found to be 40 000 - 67 000, and the purified protein was most likely to match moesin or β-actin.
Conclusions: B-cell antigen D8/17 is not associated with RHD in Guangdong province of China. Moesin or β-actin is the most likely protein to match D8/17 antigen.