Clinical versus histological diagnosis of diabetic nephropathy--is renal biopsy required in type 2 diabetic patients with renal disease?

Objecives: The clinical and histological diagnosis (gold standard) of diabetic nephropathy (dNP) and vascular nephropathy (vNP) were compared in type 2 diabetic patients with end-stage renal disease (ESRD).
Aim: The aim of the study was to investigate indication for renal biopsy in type 2 diabetic patients with renal disease.
Design: Retrospective study in diabetic patients with clinical and histological diagnosis of renal disease.
Patients and Methods: Eighty-four patients with type 2 diabetes and ESRD were investigated. Histological findings of the kidneys were available in all patients, 14 had undergone a renal biopsy before their first dialysis while a post-mortem kidney investigation was performed in 70 subjects. According to the histological findings, 66 patients had dNP and 18 subjects had vNP. The histological diagnosis was compared with the clinical diagnosis, and the sensitivity as well as the specificity of the clinical diagnosis of dNP and vNP were calculated.
Results: The clinical diagnosis was not identical with the histological diagnosis in 10 cases. In the dNP group the diagnosis was 4 false positive and 3 false negative as in the vNP group 1 false positive and 2 false negative. The sensitivity of clinical diagnosis was 95% for dNP and 89% for vNP. Specificity was 78% for dNP and 97% for vNP.
Conclusion: The sensitivity of the clinical diagnosis is very high for dNP as well as vNP. A renal biopsy is not required in the majority of type 2 diabetic patients with ESRD, especially in patients who exhibit all criteria for clinical diagnosis.