Department of Rheumatology and Immunology, Anhui Provincial Hospital, No 17 Lujiang Road, Hefei 230001, China.
Clin Rheumatol. 2012 Sep;31(9):1323-9. doi: 10.1007/s10067-012-2017-1. Epub 2012 Jun 14.
The aim of this study is to investigate the association of serum anti-C1q antibody levels with renal pathological characteristics in SLE patients with lupus nephritis. Fifty-two patients with biopsy-proven lupus nephritis were enrolled. Serum anti-C1q levels (units per milliliter) were measured before renal biopsy using ELISA kit. A cross-sectional study analyzed the association of anti-C1q antibody levels with SLE global activity, nephritic activity, and renal histopathology. Thirty-nine of 52 patients (75 %) were positive for anti-C1q antibody. Anti-C1q antibody levels were positively correlated with the values for the SLE Disease Activity Index (r = 0.628, p < 0.001), anti-nucleosome (r = 0.591, p < 0.001), and anti-dsDNA antibody (r = 0.507, p < 0.001), but negatively correlated to serum C3 (r = -0.626, p < 0.001) and C4 (r = -0.57, p < 0.001). The prevalence of anti-C1q in patients with proliferative LN (class III + class IV) was higher than those with mesangial LN (class II), but there is no statistical significance. Among different ISN/RPS classification, serum anti-C1q antibody level was highest in patients with class IV, followed by class III. The concentration of anti-C1q in patients with class IV was higher than those in class II [50.00 (23.00, 97.70) vs 20.25 (7.16, 54.78) U/ml, p<0.05]. The levels of anti-C1q antibody were positively correlated with renal active indices (r = 0.59, p < 0.001) while negatively correlated with chronic indices (r = -0.326, p < 0.05). Moreover, anti-C1q antibody was found to be positively associated with glomerular C1q deposition. These findings indicate that serum anti-C1q antibody is a valuable noninvasive biological marker for prediction of renal histopathology in lupus nephritis. Low or negative anti-C1q antibody titers might influence therapeutic decisions in SLE.
本研究旨在探讨血清抗 C1q 抗体水平与狼疮肾炎患者肾脏病理特征的关系。纳入了 52 例经肾活检证实的狼疮肾炎患者。使用 ELISA 试剂盒在肾活检前测量血清抗 C1q 水平（单位/毫升）。一项横断面研究分析了抗 C1q 抗体水平与 SLE 整体活动、肾炎活动和肾脏组织病理学之间的关系。52 例患者中有 39 例（75%）抗 C1q 抗体阳性。抗 C1q 抗体水平与 SLE 疾病活动指数（r=0.628，p<0.001）、抗核小体（r=0.591，p<0.001）和抗 dsDNA 抗体（r=0.507，p<0.001）呈正相关，但与血清 C3（r=-0.626，p<0.001）和 C4（r=-0.57，p<0.001）呈负相关。增殖性 LN（III+IV 级）患者的抗 C1q 阳性率高于系膜性 LN（II 级），但无统计学意义。在不同的 ISN/RPS 分类中，IV 级患者血清抗 C1q 抗体水平最高，其次是 III 级。IV 级患者抗 C1q 浓度高于 II 级[50.00（23.00，97.70）vs 20.25（7.16，54.78）U/ml，p<0.05]。抗 C1q 抗体水平与肾脏活动指数呈正相关（r=0.59，p<0.001），与慢性指数呈负相关（r=-0.326，p<0.05）。此外，抗 C1q 抗体与肾小球 C1q 沉积呈正相关。这些发现表明，血清抗 C1q 抗体是预测狼疮肾炎肾脏组织病理学的有价值的非侵入性生物标志物。低或阴性抗 C1q 抗体滴度可能影响 SLE 的治疗决策。
