Collapsing Glomerulopathy Superimposed on Diabetic Nephropathy.

Diabetic nephropathy (DN) is characterized by progressive increase in proteinuria and decline in renal functions. Various forms of nondiabetic kidney disease may be superimposed on DN, which can alter the progression of DN. Collapsing glomerulopathy (CG) may superimpose on DN, and is characterized by rapid worsening of renal failure and has poor prognosis. In our institute, renal biopsies were performed in diabetic patients for increasing proteinuria or worsening renal functions. There were seven cases of CG superimposed on DN. All patients except one had a history of long standing diabetes mellitus. All patients had nephrotic range proteinuria. Four patients had severe renal failure at presentation. Renal biopsy showed CG superimposed on DN. Six patients progressed to end-stage renal disease during follow-up; one patient is in chronic kidney disease-stage 3b. The development of CG contributes to an increased level or new onset proteinuria in DN, and can lead to rapid worsening of renal failure. The diagnosis of CG superimposed on DN is of prognostic significance.