Nephrotic syndrome in a patient with IgA deficiency-associated mesangioproliferative glomerulonephritis

A case of mesangioproliferative glomerulonephritis in a 55-year-old woman with selective IgA deficiency and serum antinuclear antibodies who presented with nephrotic syndrome is described. The patient did not have clinical or laboratory features of systemic lupus erythematosus (SLE) other than antinuclear antibodies. Histology of the patient's renal biopsy revealed a mesangioproliferative glomerulonephritis and direct immunofluorescence showed that paramesangial deposits contained predominant IgM with lesser IgG, C3 and C1q. These findings are identical to those previously described in a form of glomerulonephritis associated with IgA deficiency and would be atypical for lupus nephritis. Glomerulonephritis is not a well recognized complication of IgA deficiency, though it has been rarely reported in the literature. This case provides further evidence that IgA deficiency is associated with a unique immune complex-mediated glomerulopathy with characteristic immunopathological and ultrastructural features. It is the first reported case to present with nephrotic syndrome.