Sim John J, Chen Qiaoling, Cannizzaro Nancy, Fernandes Ancilla W, Pinto Cibele, Bhandari Simran K, Chang John, Schachter Asher D, Mathur Mohit
Division of Nephrology and Hypertension, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA, USA.
Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA.
Nephrol Dial Transplant. 2025 Apr 30. doi: 10.1093/ndt/gfaf084.
We assessed disease progression among patients with immunoglobulin A nephropathy (IgAN) and characterized factors associated with risk for adverse outcomes.
A retrospective longitudinal cohort (2000-2022) study of adults with biopsy-confirmed IgAN within Kaiser Permanente Southern California was performed. The outcome of interest was a composite of ≥50% estimated glomerular filtration rate (eGFR) decline, kidney failure, or mortality. Cox proportional hazards regression modeling was used to estimate hazard ratios (HR) for the eGFR decline/kidney failure with adjustment for potential confounders.
Among 655 patients with primary IgAN (31% Asian/Pacific Islander, 3% Black, 40% Hispanic/Latino, 24% White), 234 (36%) reached the composite outcome of ≥50% eGFR decline (17%), kidney failure (16%), or mortality (3%). The composite outcome occurred at a rate of 79.4 events (95%CI 69.6, 90.7) per 1000 patient-years, with a median time to event of 2.7 years. Compared to urine protein creatinine ratio (UPCR) <0.5 g/g vs 0.5 - <1 g/g, 1 - 2 g/g, and >2 g/g, the HR (95% CI) for ≥50% eGFR decline/kidney failure were 2.4 (1.1, 5.1), 3.2 (1.5, 6.6), and 5.1 (2.5, 10.4) for baseline UPCR and 5.4 (2.3, 13.0), 14.4 (16.5, 32.2), and 41.2 (17.9, 94.5) for time averaged UPCR. Lower baseline eGFR and diabetes were also associated with higher risk, while age ≥30 years was associated with lower risk for ≥50% eGFR decline/kidney failure. There were no clear trends differentiating risk by race/ethnicity.
In this large, diverse cohort, high rates of kidney outcomes occurred within a relatively short follow-up duration. Our findings suggest that IgAN carries elevated risk for kidney outcomes starting at proteinuria levels ≥0.5 g/g, in contrast to earlier perceptions that levels below 1 g/g are associated with low risk.
我们评估了免疫球蛋白A肾病（IgAN）患者的疾病进展情况，并确定了与不良结局风险相关的因素。
对南加州凯撒医疗集团内经活检确诊为IgAN的成年人进行了一项回顾性纵向队列研究（2000 - 2022年）。感兴趣的结局是估计肾小球滤过率（eGFR）下降≥50%、肾衰竭或死亡的复合结局。采用Cox比例风险回归模型估计eGFR下降/肾衰竭的风险比（HR），并对潜在混杂因素进行调整。
在655例原发性IgAN患者中（31%为亚太岛民，3%为黑人，40%为西班牙裔/拉丁裔，24%为白人），234例（36%）达到了eGFR下降≥50%（17%）、肾衰竭（16%）或死亡（3%）的复合结局。复合结局的发生率为每1000患者年79.4例事件（95%CI 69.6，90.7），事件发生的中位时间为2.7年。与尿蛋白肌酐比值（UPCR）<0.5 g/g相比，UPCR为0.5 - <1 g/g、1 - 2 g/g和>2 g/g时，基线UPCR时eGFR下降/肾衰竭≥50%的HR（95%CI）分别为2.4（1.1，5.1）、3.2（1.5，6.6）和5.1（2.5，10.4），时间平均UPCR时分别为5.4（2.3，13.0）、14.4（16.5，32.2）和41.2（17.9，94.5）。较低的基线eGFR和糖尿病也与较高风险相关，而年龄≥30岁与eGFR下降/肾衰竭≥50%的较低风险相关。按种族/民族区分风险没有明显趋势。
在这个规模大、种族多样的队列中，在相对较短的随访期内肾脏结局发生率较高。我们的研究结果表明，与早期认为低于1 g/g的水平风险较低的观念相反，IgAN从蛋白尿水平≥0.5 g/g开始肾脏结局风险升高。
