Rheumatology Division, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo 455 - 3rd floor - Room 3190 CEP, São Paulo, SP, 1246-903, Brazil.
Clin Rheumatol. 2019 Oct;38(10):2777-2783. doi: 10.1007/s10067-019-04620-3. Epub 2019 Jun 2.
BACKGROUND/OBJECTIVE: Recent studies observed an association between increased serum uric acid (SUA) levels and renal damage in lupus. However, the predictive value of UA for the development of long-term renal dysfunction in lupus nephritis (LN) is still unknown. The aim of this study was to evaluate if SUA may be a predictor of long-term renal outcome in LN.
Eighty biopsy-proven LN patients > 7 years of follow-up were selected. SUA levels were measured in sera stored at - 70 °C. All patients had serum stored from LN baseline, and 32 also had stored serum from 6 and 12 months after LN. Renal outcome was addressed after 7 years of follow-up to determine if SUA could be a predictor of long-term renal outcome. A good long-term renal outcome in 7 years was defined as a creatinine clearance (CrCl) ≥ 90.0 mL/min/1.73 m, and poor if CrCl < 90 mL/min/1.73 m. Patients were divided in two groups according to the renal outcome to assess whether SUA levels at different time points of follow-up could differentiate such groups. An ROC curve was plotted to assess accuracy.
SUA levels at baseline and 6 months were not able to differentiate good from poor long-term renal outcomes in LN (respectively p = 0.37, p = 0.28), but at 12 months (p = 0.02), they could clearly differentiate the two groups. ROC curve (12 months) accuracy was 0.76. SUA cutoff was 6.05 mg/dL (sensitivity = 0.67, specificity = 0.89, positive predictive value = 0.85, negative predictive value = 0.73).
SUA levels < 6.05 mg/dL at 12 months of follow-up is a predictor of good long-term renal outcome in lupus nephritis.
• Previous studies reported an association between increased serum uric acid level and short-term renal damage in lupus patients. • The predictive value of serum uric acid for the development of long-term renal dysfunction in lupus nephritis was never assessed. • At 12 months of follow-up serum uric acid clearly differentiated good from poor long-term renal outcome in lupus nephritis. • SUA level < 6.05 mg/dL at 12 months of follow-up was a predictor of good long-term renal outcome in lupus nephritis.
背景/目的：最近的研究观察到血清尿酸（SUA）水平升高与狼疮患者的肾损伤之间存在关联。然而，UA 对狼疮性肾炎（LN）患者长期肾功能障碍发展的预测价值仍不清楚。本研究旨在评估 SUA 是否可作为 LN 长期肾结局的预测指标。
选择 80 例活检证实的 LN 患者，随访时间超过 7 年。在 -70°C 储存的血清中测量 SUA 水平。所有患者均在 LN 基线时储存血清，其中 32 例患者还在 LN 后 6 个月和 12 个月时储存了血清。在 7 年后进行肾结局评估，以确定 SUA 是否可以预测长期肾结局。7 年内肌酐清除率（CrCl）≥90.0 mL/min/1.73 m 定义为良好的长期肾结局，CrCl<90 mL/min/1.73 m 定义为不良的长期肾结局。根据肾结局将患者分为两组，以评估随访不同时间点的 SUA 水平是否能够区分这两组。绘制 ROC 曲线以评估准确性。
基线和 6 个月时的 SUA 水平无法区分 LN 的良好和不良长期肾结局（分别为 p=0.37，p=0.28），但在 12 个月时（p=0.02），SUA 水平能够清楚地区分两组。ROC 曲线（12 个月）的准确性为 0.76。SUA 截断值为 6.05 mg/dL（敏感性=0.67，特异性=0.89，阳性预测值=0.85，阴性预测值=0.73）。
12 个月时 SUA 水平<6.05 mg/dL 是狼疮性肾炎长期肾结局良好的预测指标。
• 先前的研究报道，血清尿酸水平升高与狼疮患者的短期肾损伤有关。
• 血清尿酸对狼疮性肾炎患者长期肾功能障碍发展的预测价值从未被评估过。
• 12 个月时随访的 SUA 水平清楚地区分了狼疮性肾炎患者的良好和不良长期肾结局。
• 12 个月时 SUA 水平<6.05 mg/dL 是狼疮性肾炎长期肾结局良好的预测指标。
