RESUMO
The human cytotoxic T-lymphocyte antigen 4 (CTLA4) gene encodes proteins regulating the immune response. The polymorphism of this gene is associated with some autoimmune diseases. In this study, we analysed the distribution of the dimorphisms of exon 1 (+ 49 A/G) in bullous pemphigoid (BP) and cicatricial pemphigoid (CP), two types of autoimmune bullous skin diseases that occur in elderly people. The frequency of the exon 1 A-G genotype was marginally decreased in patients (36.4%; n = 55) compared with controls (52.8%, n = 53), but the results were not statistically significant (P = 0.09).
Assuntos
Antígenos de Diferenciação/genética , Imunoconjugados , Penfigoide Mucomembranoso Benigno/genética , Dermatopatias Vesiculobolhosas/genética , Abatacepte , Alelos , Antígenos CD , Antígeno CTLA-4 , Humanos , Polimorfismo GenéticoRESUMO
Cicatricial pemphigoid (CP) is a chronic, autoimmune, subepithelial blistering disease, characterized by the presence of antibasement membrane antibodies (BMZ) against anchoring filaments components. An association between the HLA-DQB1*0301 allele and ocular cicatricial pemphigoid has been previously reported in North American Caucasians. In this study, we compared high resolution typing HLA-DRB1 and -DQB1 alleles in 25 CP patients (50 haplotypes) with 106 geographically matched, healthy controls (212 haplotypes), who were all French Caucasians. As in American Caucasians, we confirmed a positive association of CP with the HLA-DQB1*0301 allele which was present in 54% of CP haplotypes (27/50); by contrast 21.7% (46/212) of the matched normal individuals carried the DQB1*0301allele (Pc = 7 x 10(-5); RR = 4.23). HLA-DQB1*0301 is in linkage disequilibrium with several DRB1 alleles. Only the DRB1*1101 DQB1*0301 haplotype frequency was significantly increased (24.0% in CP, 6.6% in control, Pc = 0.002). Furthermore, we observed a decrease of the frequency of the DQB1*02 allele (6% vs 25% in the control group, Pc = 0.05; RR = 0.19). The negative association corresponds to a significant decreased frequency of the DRB1*0701 DQB1*0202 haplotype (0% in CP vs 12.7%, Pc = 0.07 PC) and a non-significant decrease of DRB1*0301 DQB1*0201 (4% in CP vs 12.3%). HLA-DQB1*0301 encodes a negative charge at position DQ 57 (Asp), a critical position in peptide binding to the HLA-DQ molecule groove and therefore we speculate that this molecule may play a role in the selection of BMZ peptides in CP.
Assuntos
Genes MHC da Classe II , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Penfigoide Mucomembranoso Benigno/genética , Alelos , França/epidemiologia , Frequência do Gene , Ligação Genética , Predisposição Genética para Doença , Cadeias beta de HLA-DQ , Cadeias HLA-DRB1 , Humanos , Penfigoide Mucomembranoso Benigno/imunologia , População Branca/genéticaRESUMO
INTRODUCTION: Pemphigoid vegetans is a rare disease. It has a clinical resemblance to pemphigus vegetans, but there are histological and immunopathological features of bullous pemphigoid. CASE REPORT: We describe a case in a 57-year-old-man who had developed intertriginous vegetating plaques. Histologic examination of a skin biopsy specimen and direct immunofluorescence microscopy of a biopsy specimen were those of bullous pemphigoid. Immunoblot studies and indirect immunofluorescences of salt-split skin were negative. Direct immunoelectron microscopy was consistent with bullous pemphigoïd. DISCUSSION: Only five cases have been reported. We describe the first case including direct immunomicroscopic findings which suggest that pemphigoid vegetans is a subtype of bullous pemphigoid. The other interest was a remarkable improvement with tetracyclines.