HLA genotyping in cardiac and other extrapulmonary manifestations of sarcoidosis

Although numerous candidate genes have been identified in studies investigating the role of genetics in sarcoidosis, the strongest association has been reported with the Major Histocompatibility Complex/Human Leucocyte Antigen (MHC/HLA) region. This study aimed to evaluate HLA polymorphism and assess its association with cardiac and other extrapulmonary involvement in sarcoidosis patients.

The study included 67 patients diagnosed with sarcoidosis. A control group of 100 bone marrow donors, who had undergone HLA genotyping previously, was also included. Blood samples were collected from all participants for HLA gene polymorphism analysis. The differences in HLA genotypes were investigated between patients with and without cardiac and other extrapulmonary involvement, and between these groups and the control group.

Cardiac involvement, was present in 17.9% of the patients. The most frequently affected extrapulmonary organ was the skin (23.8%). HLA DQB103 and HLA DQB106 alleles were expressed more frequently in patients with only pulmonary involvement compared to those with extrapulmonary involvement. Conversely, HLA DQA101 was expressed more frequently in patients with extrapulmonary involvement. No statistically significant difference in the expression of HLA DRB1, HLA DQB1, and HLA DQA1 alleles was observed between sarcoidosis patients with and without cardiac involvement.

Our findings suggest that HLA DQB103 and HLA DQB106 alleles might be protective against extrapulmonary organ involvement, while HLA DQA101 could be a risk factor. These findings may contribute to the prediction of treatment response and prognosis in sarcoidosis patients.