Long-term outcome of adult-onset minimal-change nephropathy

Background. Adult-onset minimal-change nephropathy has been associated with a slower response to corticosteroids and a less benign prognosis when compared to children. However, there are few long-term outcome data reported. Methods. We have reviewed retrospectively 51 idiopathic adult-onset minimal-change nephropathy patients investigated and treated at a single centre. Results. Male to female ratio was 1:1.4, mean age at diagnosis was 37 years, and average length of follow-up was 14.1 years. Significant comorbidity was identified in 33%. A raised serum creatinine was found in 55% but returned to normal almost invariably upon remission. At presentation, hypertension was found in 47% of patients, microscopic haematuria in 33%, hypercholesterolaemia and hypertriglyceridaemia in 96%, and hyperuricaemia in 42%. Remission (complete or partial) was achieved by 46, 70 and 92% within 4, 8 and 21 weeks respectively, in patients treated with steroids; steroid resistance was encountered in 8%. The time to remission was positively correlated with age (P=0.002) and initial albumin level (P=0.005), and negatively correlated to the number of subsequent relapses (P=0.029); 33% of patients had a spontaneous remission at some time during the disease course. Patients with multiple relapses were treated with cyclophosphamide and 63% of them had remained in remission after 5 years. Hypertension was present in 25% of patients after an average interval of 11 years. At the time of the final follow-up, only three patients had a raised creatinine and all but three patients were in complete remission. Conclusions. Adult-onset minimal-change nephropathy shares the same good long-term outcome as the childhood counterpart, with sustained remission and preserved renal function.