The protective role of HLA-DRB1 13 in autoimmune diseases

Autoimmune diseases (aids) are characterized by a multifactorial aetiology and a complex genetic background,with the mhc region playing a major role. we genotyped for hla-drb1 locus 1228 patients with aids-213 with systemic lupus erythematosus (sle),166 with psoriasis or psoriatic arthritis (ps + psa),153 with rheumatoid arthritis (ra),67 with systemic sclerosis (ssc),536 with multiple sclerosis (ms),and 93 with myasthenia gravis (mg) and 282 unrelated controls. we confirmed previously established associations of hla-drb1 15 (or = 2.17) and hla-drb1 03 (or = 1.81) alleles with ms,hla-drb1 03 with sle (or = 2.49),hla-drb1 01 (or = 1.79) and hla-drb1 04 (or = 2.81) with ra,hla-drb1 07 with ps + psa (or = 1.79),hla-drb1 01 (or = 2.28) and hla-drb1 08 (or = 3.01) with ssc,and hla-drb1 03 with mg (or = 2.98). we further observed a consistent negative association of hla-drb1 13 allele with sle,ps + psa,ra,and ssc (18.3%,19.3%,16.3%,and 11.9%,resp.,versus 29.8% in controls). hla-drb1 13 frequency in the aids group was 20.0% (or = 0.58). although different alleles were associated with particular aids,the same allele,hla-drb1 13,was underrepresented in all of the six diseases analysed. this observation suggests that this allele may confer protection for aids,particularly for systemic and rheumatic disease. the protective effect of hla-drb1 13 could be explained by a more proficient antigen presentation by these molecules,favouring efficient clonal deletion during thymic selection. © 2015 andreia bettencourt et al.