[Immune complex nephropathy and hereditary deficiency of C1 esterase inhibitor (author's transl)].

Deficiency of C1 esterase inhibitor (C1-INH) was demonstrated in 7 of 22 subjects belonging to the same French family. Immune complex glomerulonephritis without lupic symptoms was discovered in one of the C1-INH deficient subjects, and in a girl of the same family the same deficiency was associated with an insulin-dependent diabetes of sudden onset. The pathophysiological consequences of complement deficiency resulting from the lack of C1 esterase inhibitor are discussed.