Pemphigus is not associated with allotypic markers of immunoglobulin kappa.

The kappa light chain constant region of immunoglobulins bears polymorphic markers involved in susceptibility to various autoimmune diseases. To determine whether it also contributes to the occurrence of pemphigus, a group of autoimmune blistering skin diseases owing to pathogenic autoantibodies, the genotypic frequencies of Km allotypes were evaluated in patients with pemphigus foliaceus or pemphigus vulgaris and ethnically-matched healthy controls in both Tunisia and France. No difference in the distribution of Km genotype or allele frequencies was observed between patients and controls in either countries. Therefore, Km allotypes do not appear to constitute a genetic factor contributing to pemphigus.