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: DRβ1* 0402/DQβ1* 0302 and DRβ1* 1401/DQβ1* 0503. Conclusions: In patients with the haplotype DRβ1* 0402/DQβ1* 0302 the affectation of 10%–30% of the corporal surface prevailed (ACS). In patients with DRβ1* 1401/DRQβ1* 0503, involvement of <10% of the ACS prevailed.