The clinico-pathological characteristics and outcome in hemolytic-uremic syndrome of adults

Twenty-eight adults who developed hemolytic-uremic syndrome (HUS) underwent a renal biopsy during the period from 1973 to 1993, and the specimens were analyzed both clinically and pathologically. The observed etiologic antecedents of HUS were infectious disease in 7 cases, medication, mainly due to cytotoxic drugs in 7 cases, post-partum in 7 cases, progressive systematic scleroderma in 1 case and unknown in 6 cases. Histologically, 17 cases were glomerular type, 3 cases were arterial type, 6 cases were mixed type and 2 cases demonstrated cortical necrosis. The preceding conditions and the histological findings appeared not to be related to each other. In the acute phase of the disease, of 11 patients who fell into severe acute renal failure (ARF) with an increase in the serum creatinine level of more than 5 mg/dl, 8 patients needed dialysis therapy while 4 patients did not recover from the disease (3 died and 1 was introduced to maintenance dialysis therapy). The incidence of thrombus in the glomerular capillaries and fibrinoid necrosis of the arterioles, the index of the expansion of glomerular subendothelial lucent zone (Glom-SE-ex), the index of glomerular sclerosing and the index of the intimal thickening of the arterioles were higher in the severe ARF than in the mild ARF. After analyzing the prognostic factors on renal survival, severe ARF, the presence of fibrinoid necrosis, severe glomerular endothelial damage and severe intimal thickening of the arterioles appeared to have a significantly adverse effect. Moreover, high Glom-SE-ex and the presence of fibrinoid necrosis also independently influenced renal survival. We thus conclude that the etiology of HUS in adults demonstrates a greater variation than that in children. Therefore, it is very difficult to predict the outcome of this disease based on the clinical findings alone, and thus a renal histological examination is considered to help in determining the long-term outcome.