Department of Internal Medicine, Division of Kidney and Dialysis, Hyogo College of Medicine, 1-1 Mukogawa-Cho, Nishinomiya, Hyogo, Japan.
Health and Counseling Center, Osaka University, Toyonaka, Osaka, Japan.
Clin Exp Nephrol. 2020 Oct;24(10):927-934. doi: 10.1007/s10157-020-01918-4. Epub 2020 Jul 8.
Steroid therapy is one of the important therapies for IgA nephropathy (IgAN), but the features of the IgAN patients who have the benefit from this therapy remained unclear.
This retrospective observational study, using data of 874 patients with IgAN analyzed the proteinuria and kidney function of IgAN patients who had beneficial effect by steroid therapy. Two advantages of the present study were a large cohort and a long observational period.
Corticosteroid therapy had ameliorated the kidney prognosis [incident rate ratio (IRR) 0.57 (95%CI 0.34-0.92), P = 0.029]. Because of interaction between kidney function and use of corticosteroid (P = 0.047), stratification analysis by kidney function revealed that prognosis of kidney function in IgAN patients whose eGFR was less than 60 ml/min/1.73m was ameliorated by corticosteroid therapy [IRR 0.50 (95%CI 0.26-0.97), P = 0.015); while, there was no change of kidney prognosis in IgAN patients whose eGFR was above 60 ml/min/1.73 m. To make the target of corticosteroid therapy for IgAN patients more clear, IgAN patients, whose eGFR were less than 60 ml/min/1.73 m, were stratified by proteinuria (1 g/day). In IgAN patients whose eGFR were under 60 ml/min/1.73 m and whose proteinuria were over 1.0 g/day, corticosteroid therapy seemed to ameliorate kidney function [IRR 0.39 (95%CI 0.19-0.86), P < 0.05]; while, there was obviously no change by corticosteroid therapy in IgAN patients whose eGFR were less than 60 ml/min/1.73 m and whose proteinuria were less than 1.0 g/day.
Our results suggested that steroid therapy was especially effective for IgAN patients whose eGFR was less than 60 ml/min/1.73 m and whose proteinuria was more than 1.0 g/day.
激素治疗是 IgA 肾病（IgAN）的重要治疗方法之一，但受益于这种治疗的 IgAN 患者的特征仍不清楚。
本回顾性观察研究使用了 874 例 IgAN 患者的数据，分析了激素治疗有效患者的蛋白尿和肾功能。本研究的两个优点是队列规模大和观察期长。
皮质类固醇治疗改善了肾脏预后[发病率比（IRR）0.57（95%CI 0.34-0.92），P=0.029]。由于肾功能和皮质类固醇使用之间存在交互作用（P=0.047），按肾功能分层分析显示，eGFR 小于 60 ml/min/1.73m 的 IgAN 患者的肾功能预后通过皮质类固醇治疗得到改善[IRR 0.50（95%CI 0.26-0.97），P=0.015）；而 eGFR 大于 60 ml/min/1.73 m 的 IgAN 患者的肾脏预后没有变化。为了使 IgAN 患者的皮质类固醇治疗目标更加明确，按蛋白尿（1g/天）对 eGFR 小于 60 ml/min/1.73 m 的 IgAN 患者进行分层。在 eGFR 小于 60 ml/min/1.73 m 且蛋白尿大于 1.0 g/天的 IgAN 患者中，皮质类固醇治疗似乎改善了肾功能[IRR 0.39（95%CI 0.19-0.86），P<0.05]；而在 eGFR 小于 60 ml/min/1.73 m 且蛋白尿小于 1.0 g/天的 IgAN 患者中，皮质类固醇治疗则无明显变化。
我们的结果表明，皮质类固醇治疗对 eGFR 小于 60 ml/min/1.73 m 且蛋白尿大于 1.0 g/天的 IgAN 患者尤其有效。
