#5201 KIDNEY BIOPSY IN PATIENTS WITH TYPE 2 DIABETES: A SINGLE CENTER OBSERVATIONAL STUDY

Abstract

Abstract Background and Aims Patients with type 2 diabetes mellitus (T2DM), may have various underlying causes contributing to kidney disease beyond diabetic nephropathy (DN). In such cases, a kidney biopsy (KB) can provide a definite diagnosis and allow for tailored treatment options. The aim of this study is to evaluate non diabetic kidney disease (NDKD) in T2DM patients and identify data to support KB indications. Method This is a retrospective observational study that included patients with T2DM who were submitted to a native KB between 2011 and 2022. We collected demographic, clinical and laboratory data at the date of biopsy. KB indication was considered in order to include the patients in the first encountered criteria defined sequentially as the presence of (1) nephrotic syndrome, (2) low or rapidly declining estimated glomerular filtration rate (eGFR), (3) nephrotic proteinuria and (4) hematuria. Results We analysed 72 patients with T2DM that were submitted to KB (Table 1). All except one patient had hypertension and 38 patients were screened for diabetic retinopathy (DR), which was present in 23 patients (60%). The criteria for KB was in most of the patients (59.7%) a low or rapidly declining eGFR, followed by nephrotic proteinuria (19.4%), nephrotic syndrome (16.7%) and hematuria (4.2%). KB showed 50% (n = 36) of patients with NDKD, 12.5% (n = 9) with NDKD and DKD and 37.5% (n = 27) with isolated NDKD. Among these patients, hypertensive nephrosclerosis (19.4%), focal segmental glomerulosclerosis (13.8%), acute interstitial nephritis (13.8%), membranous nephropathy (11.2%) and IgA nephropathy (5.6%), were the most prevalent diagnosis. Patients with DR had a higher prevalence of DKD with a positive predictive value (PPV) of 87%. On the other hand, in the absence of DR, DKD was only absent in 66.7%. Patients submitted to KB for the criteria of low or rapid declining eGFR had significantly more NDKD (p = 0.016). DKD with or without NDKD was found in patients with higher levels of albumin to creatinine ratio (p = 0.001) and HbA1c (p = 0.05). Conclusion Our data showed that NDKD is prevalent in T2DM patients, and given its potentially treatable nature, KB should be considered in T2DM patients, especially in those with low or rapid declining eGFR. DR supports the diagnosis of DKD (PPV of 87%), but alone is insufficient to exclude other causes. Patients with DKD had higher levels of albuminuria and HbA1c. Overall, more than half of the patients had hematuria, without any correlation with any group.