Crescentic IgA nephropathy.

We report five cases of crescentic IgA nephropathy. All are males, 16-60 years of age. One case each came to medical attention with uremia, nephrotic syndrome, and gross hematuria; two cases presented with microhematuria and proteinuria on routine urinalysis. All had hypertension, azotemia (serum creatinine 1.6-9.4 mg/dl), proteinuria (greater than 6 g/24 hr in four cases), hypoalbuminemia (less than 3 g/dl), and hematuria (gross in two cases). All progressed to end-stage renal failure renal failure ending in dialysis (three cases) or death from unrelated causes (two cases). Prednisone, 60 mg/day for 1 month in two patients (with two 1-g doses of iv methylprednisolone in 1 case) did not improve the serum creatinine level, but one patient subsequently experienced a less rapid fall in renal function. A crescentic glomerulonephritis was present in all biopsies (crescents in 31-80% of glomeruli; mean, 50%). The size and stage of the crescents were variable. Numerous glomeruli had focal or diffuse sclerosis. In all cases, there was a 3 or 4+ deposition of IgA. Low-intensity staining for IgG and IgM was noted in four and three patients, respectively. On electron microscopy, dense granular mesangial deposits were noted in all cases and in four patients capillary subepithelial deposits were also observed. This form of IgA nephropathy is not common, but some studies indicate that it may occur in about 5% of patients with IgA nephropathy.