用于检测抗 C1q 自身抗体的商业试剂盒的价值及其与狼疮肾炎免疫和临床活动的相关性。

Value of a commercial kit for detecting anti-C1q autoantibodies and correlation with immunological and clinical activity of lupus nephritis.

出版信息

Clin Chem Lab Med. 2015 Oct;53(11):1771-7. doi: 10.1515/cclm-2015-0072.

DOI:10.1515/cclm-2015-0072

Abstract

BACKGROUND

The association of anti-C1q antibodies (anti-C1q) with the renal activity of lupus nephritis (LN) and the methods for their determination is still a matter of debate.

METHODS

In 116 serum samples of 66 patients with biopsy proven LN, we aimed: 1) to compare the results of the determination of anti-C1q obtained by a commercial kit with a clinically validated in-house ELISA; 2) to evaluate the correlation of anti-C1q with the most important immunological and clinical parameters employed in LN, i.e., antibodies to dsDNA (anti-dsDNA), C3 and C4 complement component, haemoglobin and haematuria.

RESULTS

Good correlation and agreement between the two methods (r=0.81, p<0.0001; contingency coefficient=0.70, p<0.0001, respectively) were demonstrated. No differences were observed between the two assays by ROC curves comparison. Anti-C1q levels were significantly higher in patients with active LN [44 arbitrary units (AUs)] in comparison to those with inactive LN (23 AUs, p=0.047) and significantly correlated with anti-dsDNA (r=0.44, p<0.0001), complement fractions (C3: r=-0.33, p=0.001; C4: r=-0.29, p=0.003), haemoglobin levels (r=-0.34, p=0.0004) and the number of urinary red blood cells (r=0.26, p=0.01).

CONCLUSIONS

Our results suggest the validity of this commercial assay in detecting anti-C1q and confirm the association of anti-C1q with renal involvement of LN and the importance of introducing this parameter in the analytical panel for the evaluation of LN activity.

摘要

背景

抗 C1q 抗体（抗 C1q）与狼疮肾炎（LN）的肾脏活动之间的关联及其测定方法仍存在争议。

方法

在 66 例经活检证实的 LN 患者的 116 份血清样本中，我们旨在：1）比较商业试剂盒测定的抗 C1q 结果与临床验证的内部 ELISA 结果；2）评估抗 C1q 与 LN 中最重要的免疫和临床参数的相关性，即抗双链 DNA（抗 dsDNA）抗体、C3 和 C4 补体成分、血红蛋白和血尿。

结果

两种方法之间显示出良好的相关性和一致性（r=0.81，p<0.0001；一致性系数=0.70，p<0.0001）。通过 ROC 曲线比较，两种检测方法之间没有差异。与无活动 LN 患者（23 AU）相比，活动 LN 患者的抗 C1q 水平明显更高[44 个任意单位（AU）]（p=0.047），且与抗 dsDNA（r=0.44，p<0.0001）、补体分数（C3：r=-0.33，p=0.001；C4：r=-0.29，p=0.003）、血红蛋白水平（r=-0.34，p=0.0004）和尿红细胞数（r=0.26，p=0.01）呈显著相关。