Reversible acute renal failure from gross haematuria due to glomerulonephritis: not only in IgA nephropathy and not associated with intratubular obstruction

Seven patients with acute renal failure due to gross haematuria caused by glomerulonephritis are described. Gross haematuria lasting 4-40 days led to acute impairment of renal function of variable severity (peak plasma creatinine 1.3-12 mg/dl) and duration. While partial recovery of renal function occurred in all patients within few days, complete remission was observed only some months later. Three patients had IgA nephropathy (2 the primary form and 1 nephritis secondary to Schönlein-Henoch purpura), two patients had acute postinfectious glomerulonephritis, andtwo others had focal necrotizing (pauci-immune) glomerulonephritis. The glomerular changes seen in renal biopsy were not enough to explain per se the renal function impairment. Tubular changes, however, were severe and consisted of tubular necrosis, erythrocyte casts, erythrocyte phagocytosis by tubular cells, accompanied by interstitial damage (oedema, red-cell extravasation, and inflammatory infiltrates). Study of the renal biopsies by immunofluorescence revealed retrodiffusion of Tamm-Horsfall protein into the glomerular Bowman's space, a sign of obstructed tubular flow in any case. It is concluded that acute renal failure due to gross haematuria in glomerulonephritic patients may not occur only in IgA nephropathy, as reported so far, and is not associated with intratubular obstructio

Renal Disease in Essential Mixed Cryoglobulinaemia: LONG-TERM FOLLOW-UP OF 44 PATIENTS

The mode of presentation of renal disease in 44 patients with essential mixed cryoglobulinaemia (EMC) was: acute renal failure (two patients), acute nephritic syndrome (six patients), nephrotic syndrome (eight patients), proteinuria and/or haematuria (28 patients). Renal biopsy, performed in 35 patients, showed proliferative lesions in 33, while only minimal glomerular changes were seen in the remaining two. Immunofluorescence studies showed: IgG (85 per cent), IgA (36 per cent), IgM (90 per cent), C3 (90 per cent), Clq (47 per cent), and C4 (33 per cent) deposits, mainly located in subendothelial position. On electron microscopy, crystalloid structure of deposits and monocyte infiltration of capillary loops were the outstanding feature. The survival rate was 75 per cent at 10 years from the onset of clinical symptoms. Thirty-nine patients were followed for three to 146 months (mean 53·8). Twelve patients died, cardiovascular disease and infection being the commonest cause of death. Thirteen patients showed acute renal failure or acute nephritic syndrome: nine recovered completely, whereas the remaining four died during the acute renal episode. Three patients developed chronic renal failure, but only one required chronic dialysis. The ominous significance of renal impairment in EMC should therefore be revaluated. The high prevalence of hypertension (28/44 patients) which was refractory to treatment in six, may be important to the clinical outcom