Introduction:
Infection-related glomerulonephritis (IRGN) has evolved from its classical association with post-streptococcal infections to encompass various infectious etiologies. Over the last few decades, the adult variant of IRGN has gained prominence, with patients often presenting with comorbidities like diabetes mellitus (DM), which adversely affects renal and patient outcomes. This study aimed to compare the clinical profiles, immediate, and long-term renal and patient outcomes of biopsy-proven IRGN in diabetic patients without DKD versus non-diabetic patients.
Methods:
A single-centre, retrospective observational study was conducted between January 2010 and December 2023. The study included 117 adult patients (≥18 years) with biopsy-proven IRGN, categorized into two cohorts: those with diabetes (n=38) and those without (n=79). IRGN diagnosis was based on clinical and histopathological criteria. The clinical, laboratory, and histopathological parameters, treatment modalities, and outcomes were compared between the diabetic and non-diabetic cohorts. Kaplan-Meier survival analysis and Cox regression models were used to assess long-term patient and renal survival, while propensity score matching was performed to adjust for confounders such as age, glomerular basement membrane (GBM) thickening, and interstitial fibrosis and tubular atrophy (IFTA).
Results:
Out of 154 patients, 117 were included for final analysis after exclusions. The diabetic cohort was significantly older (mean age: 54.8 ± 15.5 years) compared to the non-diabetic group (mean age: 35.4 ± 14.9 years, p=0.001), and had a higher prevalence of hypertension (79% vs 50.6%, p=0.007). Diabetics had significantly higher serum creatinine at presentation (5.7 ± 3.4 mg/dL vs 2.7 ± 1.4 mg/dL, p<0.001), but dialysis-requiring renal failure was similar (52.6% vs 50%, p=0.46). Histologically, both groups showed similar rates of endocapillary proliferation (81.6% vs 86.1%, p=0.52), but diabetics had higher rates of moderate to severe acute tubular injury (39.4% vs 13.9%, p=0.002) and IFTA (42.1% vs 1.3%, p<0.001). The use of immunosuppression was comparable between cohorts (31.6% vs 29%, p=0.77), and remission rates at 6 months were significantly lower in diabetics (57.8% vs 93.7%, p<0.001). Diabetics had a higher rate of partial remission, while non-diabetics had a higher rate of complete remission (81% vs 26.3%, p<0.001). At 48 months, non-diabetics had superior dialysis-free renal survival (96.3% vs 44.7%, p<0.001). After propensity score matching, renal survival remained significantly better in non-diabetics (100% vs 65.2%, p<0.001). Immunosuppression did not significantly improve renal survival in either group (83.7% vs 77%, p=0.38). However, among diabetics, immunosuppression was associated with a trend towards better renal survival (61.5% vs 36%, p=0.13), although this was not statistically significant.
Conclusions:
Diabetes mellitus, even in the absence of diabetic kidney disease, is associated with poorer renal and patient outcomes in infection-related glomerulonephritis. Despite comparable use of immunosuppressive therapy, outcomes were worse in diabetics, though immunosuppression showed a trend towards benefit in diabetic patients.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.