IGHV3-associated restriction fragment length polymorphisms confer susceptibility to bullous pemphigoid

Objective: To determine whether the immunoglobulin heavy chain genes contri bute to the occurrence of bullous pemphigoid (BP), polymorphisms of both th e immunoglobulin constant IGHC and variable IGHV groups were studied in 100 Caucasian BP patients and 143 ethnically matched healthy individuals. Meth ods: To analyze the restriction fragment length polymorphism (RFLP) of the IGHG constant locus, a genomic immunoglobulin gamma 3 probe which detects p olymorphisms in the gamma constant genes was hybridized to BstEII- or BamHI /SacI-digested germline DNA, while IGHV3 sub-group polymorphism was analyze d by hybridizing a cloned VH3 probe to EcoRI-digested DNA. Results: No diff erence in the frequencies of the genotypes defined by the constant probe wa s observed between patients and controls. Analysis of the RFLP obtained wit h the VH3 probe showed that within the range of 4.5 and 1.5 kb, the observe d band pattern was composed of 8 monomorphic and 7 polymorphic bands. Among the latter, 4 allowed to define 10 different restriction patterns. One pat tern was shown to be significantly less frequent in patients than in contro ls. Conclusion: IGHV3 polymorphism might be a factor conferring susceptibil ity to BP. Copyright (C) 2001 S. Karger AG, Basel.