Kharouf Fadi, Li Qixuan, Whittall Garcia Laura P, Gladman Dafna D, Touma Zahi
Division of Rheumatology, Schroeder Arthritis Institute, Krembil Research Institute, University Health Network, University of Toronto Lupus Clinic, Toronto, ON, Canada.
Rheumatology (Oxford). 2025 May 1;64(5):2706-2714. doi: 10.1093/rheumatology/keae579.
Proteinuria is a marker of lupus nephritis (LN) activity and damage. We aimed to explore the impact of baseline proteinuria level on long-term outcomes.
We included 249 patients diagnosed with their first biopsy-proven LN. We divided patients based on baseline proteinuria into low-level (≤1 g/day, group 1; 62 patients), moderate-level (>1 and <3 g/day, group 2; 90 patients) and high-level proteinuria (≥3 g/day, group 3; 97 patients). Outcomes included complete proteinuria recovery (CPR) at 1 year, an adverse composite outcome (ESKD, a sustained ≥40% decline in eGFR, or death) and LN flares. Cox proportional hazard models were used to examine the association between baseline characteristics and long-term outcomes.
At baseline, the median [IQR] age was 33.2 [26.4, 42.4] years; median proteinuria level was 2.2 [1.0, 3.8] g/day. A total of 177 (71%) patients had proliferative lesions on biopsy; 59.7% in group 1, 78.9% in group 2 and 71.4% in group 3. The rate of achievement of CPR at 1 year was highest for group 1 and lowest for group 3. For long-term outcomes (median follow-up 8.4 years), the frequency of the adverse composite outcome was 27.4%, 26.7% and 48.5% in groups 1, 2 and 3, respectively; P = 0.003. The corresponding frequency of flares was 27.4%, 38.2% and 61.9%, respectively; P < 0.001. In the multivariable model for factors associated with long-term outcomes, there was no significant difference between groups 1 and 2; group 3 was associated with the worst prognosis.
Low-level proteinuria is commonly associated with proliferative LN and adverse long-term outcomes.
蛋白尿是狼疮性肾炎（LN）活动和损伤的标志物。我们旨在探讨基线蛋白尿水平对长期预后的影响。
我们纳入了249例经首次活检证实为LN的患者。根据基线蛋白尿水平将患者分为低水平组（≤1 g/天，第1组；62例患者）、中等水平组（>1且<3 g/天，第2组；90例患者）和高水平蛋白尿组（≥3 g/天，第3组；97例患者）。结局包括1年时蛋白尿完全缓解（CPR）、不良复合结局（终末期肾病、估算肾小球滤过率（eGFR）持续下降≥40%或死亡）和LN复发。采用Cox比例风险模型来检验基线特征与长期结局之间的关联。
基线时，年龄中位数[四分位间距]为33.2[26.4, 42.4]岁；蛋白尿水平中位数为2.2[1.0, 3.8]g/天。共有177例（71%）患者活检时有增殖性病变；第1组为59.7%，第2组为78.9%，第3组为7,1.4%。1年时CPR的实现率第1组最高，第3组最低。对于长期结局（中位随访8.4年），不良复合结局的发生率在第1组、第2组和第3组分别为27.4%、26.7%和48.5%；P = 0.003。相应的复发频率分别为27.4%、38.2%和61.9%；P < 0.001。在与长期结局相关因素的多变量模型中，第1组和第2组之间无显著差异；第3组的预后最差。
低水平蛋白尿通常与增殖性LN及不良长期结局相关。
