HLA antigens in Arabs with lichen planus.

We have HLA typed 50 Arab patients with cutaneous lichen planus who were resident in Kuwait and then compared the antigen incidence with 100 normal controls. There were no significant differences in the antigens of the HLA-ABC loci but there was a significant increase in HLA-DR1 (P = 0.0018, RR = 3.68) and HLA-DR10 (P. corr. = 0.00096, RR = 8.27) and a significant decrease in HLA DR5 (P. corr. = 0.0396, RR = 0.18). The relevance of these findings to earlier reports on lichen planus in which HLA-DR1 (but not DR10) is increased is discussed. This is the first report of HLA antigen frequency in Arab patients with lichen planus, and would support the fact that HLA DR1 is universally associated with the disease, although the more significant association appears to be with HLA-DR10.