Supplementary Material for: Histopathologic Features that Predict Transplant Glomerulopathy Progression in a Chinese Cohort

Background: Transplant glomerulopathy (TG) represents a major cause of long-term allograft failure and is the leading cause of overall post-transplant proteinuria. The extent to which histopathologic features predicts prognostication is uncertain. Methods: A single-center retrospective cohort with biopsy-proven TG was investigated. Renal biopsies were scored according to Banff 2017. The primary outcome was death-censored graft failure defined as return to dialysis or estimated glomerular filtration rate (eGFR) decreased to <15 mL/min/1.73 m². The prognostic significance of clinical and histopathologic parameters was determined using Cox proportional hazards models. Results: Data from 180 cases were available for analysis with a median follow-up of 5.0 (2.6–8.2) years. In multivariable models, ci + ct score (HR 3.1; 95% CI 2.0–4.9), cg score (HR 1.7; 95% CI 1.1–2.8), eGFR (HR 2.1; 95% CI 1.4–3.2) and proteinuria (HR 2.4; 95% CI 1.6–3.7) were independent predictors of the primary outcome. Mesangial Immunoglobulin A deposition did not significantly affect allograft survival. The only significant pathologic factors for the severity of proteinuria were cg and g + ptc (adjusted R² = 0.46) as determined by multivariable stepwise linear regression analysis. Conclusions: Severe ci + ct and cg at biopsy were predictors of unfavorable allograft prognosis in TG patients even after taking into consideration clinical characteristics. Histologic severity of cg and g + ptc was significantly associated with clinical proteinuria.