A family with hereditary angioedema and multiple immunologic disorders

A 58-year-old man with end-stage renal disease treated with long-term ambulatory peritoneal dialysis gave a history of hereditary angioedema. Results of testing of his serum for antinuclear antibody were strongly positive, and a titer of 1:2,560 for antiribosomal antibody was documented. Three of his six children reported multiple medical problems, including episodic swelling, discoid lupus, and arthritis. An indepth study of this kindred showed a number of associated immunologic disturbances. Three children had decreased C1 esterase inhibitor and decreased C4 levels. T cell enumeration revealed low proportions of suppressor cells in these three children as well as in another unaffected child. Serum IgM level was low in the propositus, and IgG level was also decreased in one of the affected children. HLA typing failed to show a clear association of class I or class II antigens with hereditary angioedema. Family members tested did not demonstrate anti-SS-A, anti-SS-B, antinuclear antibody, anti-double-stranded DNA, anti-Sm, or anti-ribonuclear protein antibodies.