METHODS: A retrospective selection of 90 hospitalized children with SLE at the Children\'s Medical Center of Second Xiangya Hospital, Central South University from January 2016 to March 2019 as the SLE group, all of whom were tested for anti-C1q antibodies. A control group was formed by collecting 70 hospitalized children with other autoimmune diseases (OAD) during the same period. The differences in anti-C1q antibody levels were compared between two groups.The correlation of anti-C1q antibodies with various indicators of SLE and LN was analyzed, and the diagnostic value of anti-C1q in SLE and LN was evaluated.
RESULTS: The serum levels of anti-C1q antibodies in the SLE group were higher than those in the OAD group (P<0.05). The SLE disease activity index score was positively correlated with anti-C1q antibodies (rs=0.371, P<0.001) and positively correlated with anti-double-stranded DNA antibodies (rs=0.370, P<0.001). The sensitivity and specificity of anti-C1q antibodies for diagnosing active SLE were 89.90% and 53.90%, respectively, with an area under the curve of 0.720 (P<0.05) and a critical value of 5.45 U/mL. The sensitivity and specificity of anti-C1q antibody levels for diagnosing active LN were 58.50% and 85.00%, respectively, with an area under the curve of 0.675 (P<0.05) and a critical value of 22.05 U/mL.
CONCLUSIONS: Anti-C1q antibodies can serve as non-invasive biomarkers for evaluating the activity of SLE or predicting the activity of LN in children.
目的: 研究抗C1q抗体与儿童活动性系统性红斑狼疮(systemic lupus erythematosus, SLE)和狼疮性肾炎(lupus nephritis, LN)的相关性,以及对活动性SLE和活动性LN的诊断价值。方法: 回顾性选择2016年1月—2019年3月中南大学湘雅二医院儿童医学中心住院的SLE患儿90例为SLE组,所有患儿均检测抗C1q抗体。收集同期住院的70例其他自身免疫性疾病(other autoimmune diseases, OAD)患儿为OAD组,比较两组抗C1q抗体水平差异,分析抗C1q抗体与SLE和LN各指标的相关性,评价抗C1q在SLE和LN中的诊断价值。结果: SLE组患儿血清抗C1q抗体水平高于OAD组(P<0.05)。SLE疾病活动性指数与抗C1q抗体呈正相关(rs=0.371,P<0.001),与抗双链DNA抗体呈正相关(rs=0.370,P<0.001)。抗C1q抗体诊断活动性SLE的灵敏度和特异度分别为89.90%和53.90%,曲线下面积为0.720(P<0.05),临界值为5.45 U/mL。抗C1q抗体水平对诊断活动性LN的灵敏度和特异度分别为58.50%和85.00%,曲线下面积为0.675(P<0.05),临界值为22.05 U/mL。结论: 抗C1q抗体可作为评价儿童SLE疾病活动性或预测LN活动性的无创生物学指标之一。.