Abstract: SA-PO0816
Additive Renal Benefits of Calcitriol in Patients with IgAN Receiving Renin-Angiotensin System Inhibitors
Session Information
- Glomerular Management: Real-World Lessons and Emerging Therapies
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Joo, Young Su, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea (the Republic of)
- Chang, Tae ik, National Health Insurance Service Ilsan Hospital, Goyang-si, Gyeonggi-do, Korea (the Republic of)
- Kim, Dong Ki, Seoul National University College of Medicine, Jongno-gu, Seoul, Korea (the Republic of)
- Han, Seung Hyeok, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea (the Republic of)
- Kang, Shin-Wook, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea (the Republic of)
- Yoo, Tae-Hyun, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea (the Republic of)
Background
Patients with immunoglobulin A nephropathy (IgAN) and moderate proteinuria are at risk of progressive renal failure despite the maximal use of renin-angiotensin system blockade (RASB). This study evaluated the efficacy of active vitamin D in reducing proteinuria in patients with IgAN receiving RASB.
Methods
In this double-blind, placebo-controlled trial, we enrolled biopsy-confirmed patients with IgAN and persistent proteinuria (0.5 g/d–3.5 g/d) after maximal use of RASB. Patients were randomized to receive either 0.25 μg/day of calcitriol or placebo for 12 months. The primary outcome was the change in the mean urinary protein-to-creatinine ratio (UPCR) during the treatment.
Results
A total of 138 patients from six medical centers were enrolled and assigned to receive a placebo (n = 69) or 0.25 ug calcitriol (n = 69), and 115 patients (83.3%) completed the study. The calcitriol group showed a greater reduction in geometric means of UPCR (mean difference: -187 mg/g, 95% confidence interval [CI], -370.6 to -4.0 mg/g; P = 0.04) and urinary albumin-to-creatinine ratio (-162 mg/g, 95% CI, -290.9 to -34.6; P = 0.01) than placebo. The annual decline of the estimated glomerular filtration rate was -0.32 ml/min/1.73 m2 (95% CI -2.54 to 1.99) in the calcitriol group and -3.64 ml/min/1.73 m2 (95% CI -5.70 to -1.58) in the placebo group (calcitriol vs placebo over time, P = 0.02). Adverse events were comparable between the groups.
Conclusion
The addition of 0.25 μg/day calcitriol to RASB safely lowered residual proteinuria and slowed eGFR decline in patients with IgAN, suggesting a potential therapeutic role for calcitriol in this population.
Funding
- Commercial Support – Hanmi Pharmaceutical Co., Ltd.