Pemphigus vulgaris and pemphigus foliaceus determined by CD86 and CTLA4 polymorphisms

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are rare autoimmune blistering diseases with presumed T-cell-dependent pathology. Activation of naïve T cells is dependent on antigen recognition, subsequent signaling through the T-cell receptor complex (signal 1), and various other interactions of T cells with antigen presenting cells that may be collectively designated as signal 2, which is unconditionally required for T-cell activation both in response to infection and to autoantigens. Among the best described interactions contributing to signal 2 are those mediated by B7 family molecules, such as CD80 and CD86 with their ligands; CD28, providing activation signals; and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), conferring inhibition. Single nucleotide polymorphisms (SNPs) within genes encoding those molecules may alter the signaling process. It is not known whether functional genetic polymorphisms within genes encoding the aforementioned proteins may increase risk for developing PV and PF and, if so, whether they might serve as biomarkers for susceptibility to these diseases. To address those questions, we examined functional single nucleotide polymorphisms within CD86 (rs1129055) and CTLA4 (rs733618 and rs5742909) genes in 61 pemphigus patients and 486 healthy controls. We found statistically significant differences in allele and genotype frequencies between PV patients and controls for rs1129055, as well as for rs5742909 among PV and PF patients. Namely, the rs1129055 A allele was significantly more common in PV patients compared with controls (35.4% versus 25.7%, respectively; P = .040), whereas the rs5742909 T allele was significantly more common in PF compared with PV patients (19.2% versus 5.2%, respectively; P = .035). The frequency of the rs5742909 T allele did not, however, differ significantly in PF or in PV compared with controls (10.5%; P = .187 and P = .100, respectively). We report a novel association of SNPs within CD86 and CTLA4 genes with pemphigus. The CD86 rs1129055 A allele appears to confer susceptibility to PV but not to PF. © 2016 Elsevier Inc. All rights reserved.