Clinical and histological correlation of diabetic nephropathy.

Renal failure in diabetes is a common cause of renal replacement therapy. The affected kidney goes through various changes in all compartments progressively. The classification of diabetic nephropathy is based on glomerular lesions and displays a heterogeneous morphology. Abnormalities in tubulointerstitial and vascular compartments are important in assessing the outcome of these patients. We applied the new pathologic classification of diabetic nephropathy by Tervaert et al to classify the renal damage in diabetes. This is a prospective study over two years. We analyzed 74 renal biopsies in diabetic patients, both type-1 and type-2. Indications for biopsy were rapid onset of proteinuria, absence of retinopathy, presence of hematuria, active urine sediment, and rapid unexplained deterioration of renal function. Biopsy was done to rule out nondiabetic renal disease or any other associated pathology with diabetic nephropathy. In our study, 53 patients were male and 21 patients were female. Age ranged from 27 to 82 years. The mean ± standard deviation age at the time of the biopsy was 54.09 ± 11.59 years. Mean duration of diabetes was 10.2 years. Proteinuria ranged from 1 to 26 g. Type-111 histopathological lesion was the most common lesion observed in our series. There was a correlation between the degree of tubulo-interstitial damage with renal function. There was no correlation between the fundal changes and degree of proteinuria with the histological class of diabetic nephropathy. Application of the classification by Tervaert et al to diabetic lesions reduces the inter-observer variability and also helps in prognosticating and management of patients.