Presence of a D8/17 B lymphocyte marker and HLA-DR subgroups in patients with rheumatic heart disease.

Objective: The aim of our study was to investigate the association of HLA antigens and a non-HLA protein D8/17 with rheumatic heart disease and its pattern of cardiac involvement.

Methods: This cross- sectional observational study included 35 children and 12 adult patients who have rheumatic heart disease and 35 healthy children and 12 healthy adult controls. After physical examination, all patients and control group members were evaluated with 2D and color-coded echocardiography. B- lymphocyte D8/17 expression was tested by a flow cytometry assay. HLA genotyping was performed using polymerase chain reaction sequence-specific primers. In statistical analysis, Chi-square, unpaired t and Mann-Whitney U tests were used for comparison groups.

Results: The percentage of the D8/17-expressing B lymphocytes of the patient group was significantly higher than of the control group (77.3±15.6% vs. 67.7±20.0%, p=0.013). When compared with the control group, the HLA DRB5 (38.6% vs. 13.6%, p=0.007) and HLA DRB1*15 (31.8% vs. 9.0%, p=0.008) expression levels of the patient group were significantly higher and the DRB4 expression of the patient group was significantly lower (29.5% vs. 50.0%, p=0.049).

Conclusion: Our findings support the association between HLA Class 2 subgroups and rheumatic heart disease, and an association between D8/17 expression and rheumatic heart disease. Further studies including higher number of patients and control group members should be performed for the confirmation of our results.