Differential HLA class I and II associations in pemphigus foliaceus and pemphigus vulgaris patients from an endemic brazilian region

Abstract

Aim Pemphigus comprise a group of blistering diseases caused by autoantibodies against desmogleins (Dsg). Two major clinical forms have been recognized: pemphigus foliaceus (PF) and pemphigus vulgaris (PV). The Northeast region of Sao Paulo State, Brazil, is endemic for both forms of pemphigus. In this study, we evaluated the association of HLA class I and II alleles with susceptibility to PF and PV in this Brazilian population. Methods All patients (86 with PF and 82 with PV, exhibiting anti-Dsg1 antibodies for PF and anti- Dsg1/3 for PV) and 1592 controls were from the same region. HLA typing was carried out using PCR-SSOP. The allelic frequencies and comparative analyses were performed using Fisher’s exact test and Odds Ratio. P ⩽ 0.002 was considered to be significant. Results Susceptibility to PF was associated with HLA-A∗11, A∗33, B∗14, HLA-DRB1∗01:01/ ∗01:02/∗16:01, DQA1∗01/∗01:02/∗03, and DQB1∗05:01, whereas HLA-A∗02, HLA-DRB1∗07:01/∗11:01/∗13:01, DQA1∗05 and DQB1∗03:01 were associated with protection. Susceptibility to PV was associated with HLA-A∗26, HLA-B∗38, HLA-C∗12 and HLA-DRB1∗04:02/∗08:04/∗14:01, DQA1∗03/∗03:01 and DQB1∗03:02/∗05:03, whereas HLA-B∗15 and HLA-DRB1∗07:01, HLA-DQB1∗06:02 were related to protection. Conclusion Historically, our region is endemic for PF, which affects younger and rural zone patients. In the last two decades, PV incidence has dramatically increased surpassing PF incidence, affecting younger and urban patients, and also becoming endemic. We describe for the first time the differential associations for PF and PV in the same Brazilian population. Although only two alleles groups (DQA1∗03 and DRB1∗07:01) were shared by both pemphigus disorders, the results of the present study emphasize the distinct pattern of HLA susceptibility/protection alleles. A.M. Roselino: Grant/Research Support; Company/Organization; FAPESP.