KIDNEY BIOPSY FINDINGS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

Abstract Background and Aims The aim of the study is to evaluate kidney biopsy findings other than renal diabetic changes in patients with type 2 diabetes mellitus. Method Diabetic patients with kidney biopsy between January 2003 and January 2020 were enrolled to the study. Kidney biopsy was performed to patients with suspicion of kidney disease other than diabetic nephropathy. The suspicious cases were patients without diabetic retinopathy, diabetes mellitus history less than 5 years, creatinine increase faster than expected course and hematuria. Demographic features, biopsy finding were all noted. Results Totally, 135 patients’ data were evaluated in which 54.1% was male. Demographic characteristics of the patients and laboratory data are given in Table 1. Mean age was 55.4±11 years and mean diabetes duration was 6.9±6.3 years. Mean duration of diabetes was 5.3±5.5 years in patients with nondiabetic nephropathy whereas it was 10.2±6.4 and 11.2±7.6 years in patients with diabetic and/or nondiabetic pathologies respectively (p<0.05). Serum creatinine and proteinuria level were lower, and hemoglobin levels were higher in patients with nondiabetic nephropathy (p <0.05).C3 was low in 3.7% of patients. ANA and ANCA positivity were seen in 8.1% and 3.7% of the patients, respectively. Patients without diabetic retinopathy was 81.7% of the total cohort. Biopsy indications were renal insufficiency (8.9%), nephrotic syndrome (24.4%), non-nephrotic proteinuria (16.4%), renal insufficiency with nephrotic range proteinuria (25.9%), renal insufficiency with non-nephrotic proteinuria (24.4%). Mean glomeruli number was 19.3±11.1. Ten patients had macroscopic hematuria in which all resolved with conservative care. Early diabetic changes, diffuse and/or nodular glomerulosclerosis were present in 3.1% and 96.9% of diabetic patients, respectively. Biopsies with diabetic changes with other nondiabetic pathologies were 3% of the biopsies. Isolated nondiabetic nephropathy was found in 23.7% of patients. Pathologic findings other then diabetic changes were as follows in patients without diabetic nephropathy: focal segmental glomerulosclerosis (FSGS) 49.5%, membranous glomerulonephritis 14,1%, Ig A nephropathy 12,1%, membranoproliferative glomerulonephritis 5 %, crescentic glomerulonephritis 4,1%, acute tubular necrosis 4,1%, amyloidosis 3%, tubulointerstitial damage 2%, others 6,1%. Conclusion Biopsy in diabetic patients is beneficial to show both diabetic nephropathy and other kidney pathologies. Kidney biopsy may be performed if there is suspicion of other glomerular pathologies. Focal segmental sclerosis was the most common pathology in our patients without diabetic nephropathy