Polymorphism of histocompatibility class II antigens coded with the DRB gene in in familial sarcoidosis in Poland

Several studies suggested association between some human leukocyte antigen (HLA) alleles and sarcoidosis, but none has been conclusive. To confirm possible association of sarcoidosis with HLA-DRB1, -DRB3,- DRB4, -DRB5 associated alleles HLA-DR genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 17 polish families with familial sarcoidosis and in 101 healthy controls. The families with sarcoidosis consisted of 31 affected first-degree relatives from 16 families, 2 affected cousins from 1 family and 78 healthy relatives of those patients. We found 3 varieties of familial sarcoidosis: a) in parent and offspring (5 pairs), b) in siblings (10 sib pairs and 1 sib triplet) and in cousins (1 family). Genotyping for HLA-DRB1,-DRB3,-DRB4,-DRB5 revealed an over-representation of HLA-DR5(12) and DRw52 among antigens shared by affected relatives comparing to the control group. A significant increase in the frequency of HLA-DR7 and HLA-DRw53 antigens (p < 0.05) was found in subjects from the control group. Comparing the group of family members (affected and healthy relatives taken together, n = 111) with the control group (n = 101) we found a significant differences in the distribution of HLA-DR2(15), HLA-DR5(12), HLA-DR6, HLA-DR9 and HLA-DRw52. Those antigens were more frequent (p < 0.05) in members from families with sarcoidosis. The frequencies of HLA-DR1, HLA-DR2(16), HLA-DR7 and HLA-DRw53 were significantly higher (p < 0.05) in the control group. Presented results suggest that HLA-DRB alleles contribute to the susceptibility to sarcoidosis in the Polish population.