PGNMID in a patient with diabetes mellitus

Diabetic nephropathy is a well known complication of diabetes mellitus and the leader cause of end -stage renal disease worldwide. Nonetheless, other forms of renal involvement can occur in diabetic population. Since it has prognostic and therapeutic implications, differentiating non-diabetic renal disease from diabetic nephropathy is of great importance. We report an 80-year-old man with well-controlled type 2 diabetes mellitus and hypertension, who presented with rapid deterioration of renal function, nephrotic proteinuria, microscopic hematuria and leukocyturia. The atypical clinical presentation prompted us to perform a kidney biopsy. A diagnosis of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (light chain only variant) was made, with however some chronic histological aspects which made us took a conservative therapeutic attitude. We emphasize that other causes of chronic proteinuric kidney disease should be considered in patients with type 2 diabetes mellitus, based on clinical suspicion, absence of other organ damage and mostly if an atypical presentation is seen. We review the spectrum of monoclonal gammopathies of renal significance, focusing on this rare and newly describe entity.