Complement polymorphism in herpes gestationis: association with C4 null allele.

Abstract

Herpes gestationis (HG) is a rare, pregnancy-related skin disease characterized by the production of an autoantibody to a component of the hemidesmosome. It is associated with the class II antigens HLA-DR3 and HLA-DR4, but its potential association with the "class III antigens" C2, C4, and factor B has not previously been studied. Our purpose was to study complement polymorphism in HG. Using electrophoresis and immunofixation techniques, we determined the allele frequencies of C4A, C4B, C3, and factor B in 42 patients with a history of HG. Ninety percent of patients carried a C4 null allele (C4*QO). No statistically significant association with C3 or factor B alleles was seen. HG is associated with the presence of a C4*QO. Whether the C4*QO is the primary genetic association, or whether the C4*QO is related to its linkage disequilibrium with DR3 and DR4 has yet to be determined.