Anaphylactoid purpura and familial IgA nephropathy

I gA nephropathy has become recognized worldwide as a fairly common form of glomerulonephritis. The diagnosis is established by the predominance of IgA in the mesangial immune-complex deposits in the glomeruli, usually accompanied by C3 and sometimes b IgG and IgM. Since the original description in 1968 [l , 3 it has been generally assumed that IgA nephropathy develops randomly in persons. However, increased, awareness of instances of biopsy-proven IgA nephropathy in two or more members of the same family [Z-4] has strengthened the hypothesis that a hereditary factor is important in some patients. A significant development within the past decade has been the immunologic studies of these cases and the discovery of similar changes in patients with anaphylactoid purpura; namely, the presence of IgA in the mesangium of renal biopsy specimens [5-71. This similarity prompted Baart de la Faille-Kuyper et al [B] and Meadow and Scott [9] to suggest that isolated primary IgA nephropathy may be a monosymptomatic form of anaphylactoid purpura. The difference between these two entities is primarily based on the vascular involvement of the skin, joints, and gastrointestinal tract present only in, patients with anaphylactoid purpura. An argument for a relationship between the two diseases is their occasional, although rare, occurrence in the same family [g-11]. We herein report on a family with IgA nephropathy, one member of which had recurrent purpuric rashes accompanied by severe involvement of the kidneys and eventual death ,from cerebral hemorrhage after development of renal failure. This is the first description of anaphylactoid purpura associated with familial IgA nephropathy in an adult.