Clinical outcomes of renal transplant recipients with and without post-transplant post-infectious glomerulonephritis: a propensity score-matched analysis

Background Post-infectious glomerulonephritis (PIGN) is a rare but potentially serious cause of kidney injury following infection. This study aimed to compare long-term renal outcomes and comorbidities between kidney transplant recipients who underwent allograft biopsy with and without a diagnosis of PIGN. Methods We retrospectively identified patients from a large global multicenter database. De novo PIGN patients were matched 1:1 with non-PIGN patients using propensity score matching based on age, sex, body mass index, systolic blood pressure, comorbidities, and baseline kidney function. Clinical outcomes including acute rejection, chronic kidney disease (CKD) progression, dialysis, malignancy, and mortality were assessed using hazard ratios (HRs) and Kaplan-Meier survival analysis. Results The incidence of post-transplant PIGN was 0.016% among renal transplant recipients. After matching, baseline characteristics were comparable. The mean age was 45.4 years in the PIGN group and 43.3 years in the non-PIGN group. Acute rejection was significantly higher in the PIGN group (HR 1.833; 95% CI 1.107–3.037; p = 0.012). Malignancy was more common in the PIGN group (p<0.0001). Other outcomes, including acute kidney injury (HR 1.150), stage 3-5 CKD progression, and dialysis use, did not show statistically significant differences. Kaplan-Meier analysis confirmed a significant difference only in acute rejection (log-rank p = 0.049). Conclusions PIGN is associated with an increased risk of acute rejection following transplantation. While managing infection in patients with PIGN, immunosuppressive therapy might be tapered cautiously to avoid precipitating allograft rejection.