A profile of patients with minimal change nephropathy between 2001 and 2010 at the Witwatersrand Academic Complex

Abstract

Available literature on primary minimal change nephropathy (MCN) predominantly reflects Western and Asian populations, with little data describing the disease in black patients. We therefore studied the demographic and clinical profile of patients presenting with MCN at the Witwatersrand Academic Complex. The results of 1,618 renal biopsies performed at our centre between 2001 and 2010 were reviewed; 47 patients with MCN were identified (prevalence of 2.9%).The patients were predominantly of black race (83%), the male : female ratio was 1.04:1 and the mean age was 31.8± 12.1 years. The majority of patients (90%) fitted the criteria for the nephrotic syndrome. 18% of patients had elevated serum creatinine levels and 6.4% had associated hypertension. An association was found between gender and age; with a predominance of males amongst younger patients (less than 30 years) compared to a predominance of females amongst the older patients. Records of treatment and outcomes were available for 28 patients, all of whom received initial corticosteroid therapy (average dose of prednisone 0.8mg /kg/day). The average duration of therapy was 29 weeks. 57.1% achieved remission with no further relapse. No clinical or demographic parameters were identified that predicted response to corticosteroid therapy. 39.2% of patients had probable steroid dependance/resistance. Of these patients, 58.3% had a single relapse and 41.7% had double relapses. The mean time to relapse was 27.8±19.4 months with 83% of patients relapsing within 48 months; the mean time to relapse was longer in males (39.3±17.5 months) as compared to females who relapsed in 18±16.9 months, which was significant at the 10% level (P = 0.09). MCN is rare amongst Black Africans but should be considered in the differential diagnosis of nephrotic syndrome. The disorder in these patients may be less responsive to corticosteroids and a longer course of therapy may be required to induce remission. Males may be more likely to remain in remission for a longer time period.