HEREDITARY C2 DEFICIENCY ASSOCIATED WITH NON-SYSTEMIC GLOMERULONEPHRITIS

Abstract

A patient with non-systemic idiopathic glomerulonephritis had a complete deficiency of complement C2. The clinical course, histological findings and serological abnormalities are reported in detail. The renal disease was a mild glomerulonephritis with mesangial and subendothelial immune deposits comprising Ig[immunoglobulin]G, IgM and complement C3, increased mesangial matrix without significant cell proliferation. An immunogenetic analysis of the patient''s family was carried out. The homozygous complement C2 deficiency was associated with heterozygotism for HLA-A, B and D. Only one of the complement C2 deficient genes was associated with the expected HLA-A10, B18 haplotype and the propositus was HLA-D2 negative. Non-systemic glomerulonephritis should be included in the variety of immunological disorders associated with a complement deficient state. Complement C2 deficiency does not seem to be related specifically to a given histological variety of glomerulonephritis.