HLA haplotypes and class II molecular alleles in Argentinian patients with pemphigus vulgaris

Background. Pemphigus is a group of chronic blistering autoimmune diseases of which pemphigus vulgaris (PV) is the more frequent clinical form. The association of PV with the HLA serotypes suggests that there is a genetic predisposition to the disease. Objectives: To determine the frequency of class I and class II HLA antigens and the allelic variants of the class II HLA antigens, DR and DQ, in patients with PV and to determine the relative risk. Methods. An observational, prospective, transverse, and controlled study carried out between 1995 and 1999. Forty-seven patients with a diagnosis of PV and a control sampling of 199 unselected individuals from the same ethnic group were included. The HLA alleles were determined by polymerase chain reaction. Results: No significant associations were detected between HLA A, B, or C and our patients. The DR and DQ molecular alleles positively associated with PV were two different haplotypes: DRbeta1* 0402/DQbeta1* 0302 and DRbeta1* 1401/DQbeta1* 0503. Conclusions. In patients with the haplotype DRbeta1* 0402/DQbeta1* 0302 the affectation of 10%-30% of the corporal surface prevailed (ACS). In patients with DRbeta1* 1401/DRQbeta1* 0503, involvement of <10% of the ACS prevailed.