Department of Rheumatology, and the Department of Immunology, Servidor Publico Estadual Hospital, São Paulo, Brazil.
J Rheumatol. 2012 Oct;39(10):1948-54. doi: 10.3899/jrheum.110201. Epub 2012 Sep 1.
Monocyte chemotactic protein (MCP-1), involved in the pathogenesis of lupus nephritis (LN), has recently been indicated as a new biomarker of kidney activity in systemic lupus erythematosus (SLE). Our aim was to assess urinary MCP-1 (uMCP-1) as a biomarker of renal activity in patients with SLE and to compare it to other disease activity markers, using the ELISA.
Seventy-five female Brazilian patients with SLE and a control group participated in our study. Patients with SLE were distributed among 3 groups according to kidney involvement and classified according to disease activity based on clinical and laboratory measures such as urinary sediment, proteinuria, kidney function, C3, C4, anti-dsDNA, disease activity index, and renal SLE disease activity index. The serum and uMCP-1 concentrations were measured by sandwich ELISA.
In the A-LN group (active lupus nephritis: SLE with kidney involvement), the concentration of uMCP-1 was significantly higher than in other groups. A cutoff point was established using the results of the control group to apply this test in the detection of LN. A-LN had a higher frequency of positive results for uMCP-1 in comparison to the other groups (p < 0.001). To detect disease activity in patients with LN, a new cutoff was determined based on the results of patients with SLE with kidney involvement. Setting specificity at 90%, the sensitivity of the test was 50%.
The high specificity makes uMCP-1 a useful test as a predictor of kidney activity in SLE, especially when associated to other measures used in clinical practice.
参与狼疮肾炎（LN）发病机制的单核细胞趋化蛋白（MCP-1）最近被认为是系统性红斑狼疮（SLE）中肾脏活动的新生物标志物。我们的目的是评估狼疮患者尿液中 MCP-1（uMCP-1）作为肾脏活动的生物标志物，并使用 ELISA 与其他疾病活动标志物进行比较。
75 名患有 SLE 的巴西女性患者和对照组参与了我们的研究。根据肾脏受累情况，将 SLE 患者分为 3 组，并根据临床和实验室指标（如尿沉渣、蛋白尿、肾功能、C3、C4、抗 dsDNA、疾病活动指数和肾脏 SLE 疾病活动指数）将其分为疾病活动组。通过夹心 ELISA 测量血清和 uMCP-1 浓度。
在 A-LN 组（活动期狼疮肾炎：有肾脏受累的 SLE）中，uMCP-1 的浓度明显高于其他组。使用对照组的结果建立了一个截断点，以将该测试应用于 LN 的检测。与其他组相比，A-LN 中 uMCP-1 的阳性结果频率更高（p <0.001）。为了检测 LN 患者的疾病活动度，根据有肾脏受累的 SLE 患者的结果确定了新的截断值。在设定特异性为 90%的情况下，该测试的灵敏度为 50%。
高特异性使 uMCP-1 成为一种有用的检测方法，可作为预测 SLE 肾脏活动的指标，特别是与临床实践中使用的其他措施结合使用时。
