ABSTRACT
BACKGROUND: Pemphigus is an autoimmune blistering disease with pemphigus vulgaris (PV) and foliaceus (PF) as the two major histological subtypes. Associations with HLA molecules have been suggested, but specific HLA risk variants as well as non-HLA risk variants remain to be discovered. METHODS: We performed a two-stage genome-wide association study in the Chinese Han population through a genome-wide discovery analysis and follow-up validation analysis in a total number of 210 PV, 159 PF and 2493 healthy controls. HLA imputation as well as high coverage next generation sequencing based HLA genotyping was employed to investigate the association of classical HLA alleles and amino acid change. RESULTS: We have discovered independent novel associations with PF at rs2178077 on 12q24.33, located next to RAN (PPF = 1.57 × 10-9 ) and rs3888722 within the MHC region (P = 6.73 × 10-9 ). For the HLA variants, we confirmed independent genome-wide level risk associations in HLA-DQB1 and HLA-DRB1, with DQB1*05:03 to be the strongest association with PV (P = 8.59 × 10-68 , OR = 31.16) and PF (P = 4.84 × 10-17 , OR = 5.64). In addition, DRB1*14 was demonstrated to be a second independent variants (P = 4.2 × 10-63 , OR = 35.47) for PV, while DRB1*04:06 was demonstrated to be the second independent signal (P = 7.44 × 10-13 , OR = 5.58) for PF. CONCLUSIONS: These findings advance our understanding of the genetic basis of pemphigus susceptibility and may offer opportunities for risk prediction and preventive treatment for pemphigus, in particular for PV.
Subject(s)
Genetic Predisposition to Disease/epidemiology , High-Throughput Nucleotide Sequencing/methods , Pemphigus/epidemiology , Pemphigus/genetics , Asian People/genetics , Case-Control Studies , Causality , China/epidemiology , Female , Gene Frequency , Genome-Wide Association Study , HLA-DQ beta-Chains/genetics , HLA-DRB1 Chains/genetics , Humans , Male , Pemphigus/pathology , Prevalence , Reproducibility of ResultsABSTRACT
BACKGROUND: Dapsone is used in the treatment of infections and inflammatory diseases. The dapsone hypersensitivity syndrome, which is associated with a reported mortality of 9.9%, develops in about 0.5 to 3.6% of persons treated with the drug. Currently, no tests are available to predict the risk of the dapsone hypersensitivity syndrome. METHODS: We performed a genomewide association study involving 872 participants who had received dapsone as part of multidrug therapy for leprosy (39 participants with the dapsone hypersensitivity syndrome and 833 controls), using log-additive tests of single-nucleotide polymorphisms (SNPs) and imputed HLA molecules. For a replication analysis, we genotyped 24 SNPs in an additional 31 participants with the dapsone hypersensitivity syndrome and 1089 controls and performed next-generation sequencing for HLA-B and HLA-C typing at four-digit resolution in an independent series of 37 participants with the dapsone hypersensitivity syndrome and 201 controls. RESULTS: Genomewide association analysis showed that SNP rs2844573, located between the HLA-B and MICA loci, was significantly associated with the dapsone hypersensitivity syndrome among patients with leprosy (odds ratio, 6.18; P=3.84×10(-13)). HLA-B*13:01 was confirmed to be a risk factor for the dapsone hypersensitivity syndrome (odds ratio, 20.53; P=6.84×10(-25)). The presence of HLA-B*13:01 had a sensitivity of 85.5% and a specificity of 85.7% as a predictor of the dapsone hypersensitivity syndrome, and its absence was associated with a reduction in risk by a factor of 7 (from 1.4% to 0.2%). HLA-B*13:01 is present in about 2 to 20% of Chinese persons, 1.5% of Japanese persons, 1 to 12% of Indians, and 2 to 4% of Southeast Asians but is largely absent in Europeans and Africans. CONCLUSIONS: HLA-B*13:01 was associated with the development of the dapsone hypersensitivity syndrome among patients with leprosy. (Funded by the National Natural Science Foundation of China and others.).
