Clinical Predictors and Histopathological Spectrum of Nondiabetic Kidney Disease in Type 2 Diabetes.

Abstract

Introduction: When a patient's presentation raises suspicions for conditions other than diabetic kidney disease (DKD), such as sudden onset proteinuria <5 years after the onset of type 2 diabetes, proteinuria without retinopathy or neuropathy, acute kidney injury, active urinary sediment, or hematuria, clinically indicated kidney biopsies are typically carried out. Consequently, a high incidence of non-DKD (NDKD) in clinical biopsies from diabetes individuals is not unexpected. The purpose of the study is to investigate the clinical predictors, prevalence and histopathological spectrum of NDKD in patients with type 2 diabetes mellitus.

Materials and methods: Dayanand Medical College and Hospital in Ludhiana conducted this cross-sectional observational study. After taking informed consent, 43 patients with diabetes who were suspected of having NDRD had kidney biopsies based on either or both of the following criteria: (1) Hematuria (red blood cell [RBC] casts, RBC >5/hpf). (2) Unexpected elevations in serum creatinine of more than 2 mg/dL. (3) Nephrotic syndrome with sudden onset. (4) Renal failure without diabetic retinopathy (DR). (5) DM duration <5 years. (6) Nephrotic range massive proteinuria with normal renal function. (7) Normal or negligible proteinuria along with severe renal insufficiency (serum creatinine >2 mg/dL) (<500 mg/dL).

Results: (1) Of the 43 patients, 24 (56.0%) had pure NDKD. Four patients (9.3%) had mixed renal disease, while 15 patients (35%) had DKD. (2) The most prevalent NDKD was acute interstitial nephritis (AIN) (12%), which was followed by immunoglobulin A (IgA) nephropathy, localized proliferative glomerulonephritis and crescentic glomerulonephritis (7.0% each). The most prevalent pathology observed in mixed renal disease was DN with AIN. (3) The duration of hypertension was 4.98 ± 2.86 years in the group without DKD and 8.07 ± 4.65 years in the group with DKD, both of which were statistically significant. (4) Compared to the DKD group, more patients in the NDKD group had shorter DM duration (<5 years). A greater proportion of individuals in the DKD group had DM for more than 10 years. (5) Compared to the NDKD group, there were more NPDR patients in the DKD group.

Conclusion: Since several diseases, including MN, IgA nephropathy and AIN, are frequently treatable or even curable, our study demonstrated the need for early suspicion and diagnosis of NDKD.