Colquhounia Root Tablet as an immune-metabolic adjunct for residual kidney risk in heavy-proteinuric type 2 diabetic kidney disease: a propensity-score-matched real-world study

Objective: To assess the association between Colquhounia Root Tablet (CRT), a Tripterygium hypoglaucum-derived immune-metabolic modulator, and kidney outcomes in type 2 diabetic kidney disease (DKD) patients with heavy proteinuria despite guideline-directed therapy (renin-angiotensin system blockade, SGLT2 inhibitors, finerenone). Methods: A retrospective propensity score-matched cohort study was conducted using hospital-based electronic health records. Patients with heavy-proteinuric type 2 DKD (UACR > 300 mg/g) were matched 1:1 (159 pairs). The primary endpoint was major adverse kidney events (MAKE: ≥57% sustained eGFR decline, end-stage renal disease, or kidney-related death), analyzed using multivariable-adjusted flexible parametric survival models. Results: The matched cohort had a median UACR of 1818 mg/g; 40.2% were classified as KDIGO very high risk. Over 5 years, CRT use was associated with lower MAKE incidence (52.6% vs 70.9%; adjusted HR 0.60; 95% CI, 0.43–0.85; p = 0.004), slower annual eGFR decline (−5.08 vs − 7.05 mL/min/1.73 m2/year; p < 0.001), and greater UACR reduction at 12 months (−52.8% vs 1.8%; p < 0.001), with comparable safety. Conclusion: Adjunctive CRT was associated with improved kidney outcomes in high-risk heavy-proteinuric DKD, supporting future randomized trials targeting immune-metabolic phenotypes with persistent proteinuria and residual risk.