Satirapoj Bancha, Kitiyakara Chagriya, Leelahavanichkul Asada, Avihingsanon Yingyos, Supasyndh Ouppatham
Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, 315 Rachavitee Road, Phyathai, Bangkok, 10400, Thailand.
Division of Nephrology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
BMC Nephrol. 2017 Aug 4;18(1):263. doi: 10.1186/s12882-017-0678-3.
Tubulointerstitial injury is important to predict the progression of lupus nephritis (LN). Urine neutrophil gelatinase-associated lipocalin (NGAL) has been reported to detect worsening LN disease activity. Thus, urine NGAL may predict renal outcomes among lupus patients.
We conducted a prospective multi-center study among active LN patients with biopsy-proven. All patients provided urine samples for NGAL measurement by ELISA collected from all patients at baseline and at 6-month follow-up after induction therapy.
In all, 68 active LN patients were enrolled (mean age 31.7 ± 10.0 years, median UPCR 4.8 g/g creatinine level with interquartile range (IQR) 2.5 to 6.9 and mean estimated glomerular filtration rate (GFR) 89.6 ± 33.7 mL/min/1.73 m). At baseline measurement, median urinary NGAL in complete response, partial response and nonresponse groups was 10.86 (IQR; 6.16, 22.4), 19.91 (IQR; 9.05, 41.91) and 65.5 (IQR; 18.3, 103) ng/mL, respectively (p = 0.006). Urinary NGAL (ng/mL) correlated positively with proteinuria and blood pressure, and correlated negatively with serum complement C3 level and estimated GFR. Based on ROC analysis, urinary NGAL (AUC; 0.724, 95%CI 0.491-0.957) outperformed conventional biomarkers (serum creatinine, urine protein, and GFR) in differentiating complete and partial response groups from the nonresponse group. The urine NGAL cut-off value in the ROC curve, 28.08 ng/mL, discriminated nonresponse with 72.7% sensitivity and 68.4% specificity.
Urine NGAL at baseline performed better than conventional markers in predicting a clinical response to treatment of active LN except serum complement C3 level. It may have the potential to predict poor response after induction therapy.
肾小管间质损伤对于预测狼疮性肾炎（LN）的进展很重要。据报道，尿中性粒细胞明胶酶相关脂质运载蛋白（NGAL）可检测LN疾病活动的恶化情况。因此，尿NGAL可能预测狼疮患者的肾脏结局。
我们对经活检证实的活动性LN患者进行了一项前瞻性多中心研究。所有患者均提供尿液样本，通过酶联免疫吸附测定法（ELISA）在基线时以及诱导治疗后6个月随访时测量NGAL。
总共纳入了68例活动性LN患者（平均年龄31.7±10.0岁，尿蛋白肌酐比值（UPCR）中位数为4.8g/g肌酐，四分位间距（IQR）为2.5至6.9，平均估计肾小球滤过率（GFR）为89.6±33.7mL/min/1.73m²）。在基线测量时，完全缓解、部分缓解和无缓解组的尿NGAL中位数分别为10.86（IQR；6.16，22.4）、19.91（IQR；9.05，41.91）和65.5（IQR；18.3，103）ng/mL（p = 0.006）。尿NGAL（ng/mL）与蛋白尿和血压呈正相关，与血清补体C3水平和估计的GFR呈负相关。基于ROC分析，在区分完全缓解和部分缓解组与无缓解组方面，尿NGAL（AUC；0.724，95%CI 0.491 - 0.957）优于传统生物标志物（血清肌酐、尿蛋白和GFR）。ROC曲线中尿NGAL的截断值为28.08ng/mL，鉴别无缓解的敏感性为72.7%，特异性为68.4%。
除血清补体C3水平外，基线时的尿NGAL在预测活动性LN治疗的临床反应方面比传统标志物表现更好。它可能具有预测诱导治疗后反应不佳的潜力。
