Smykał-Jankowiak Katarzyna, Niemir Zofia I, Polcyn-Adamczak Magdalena
Laboratory for Molecular Nephrology, Department of Nephrology, Transplantology and Internal Medicine, Poznan University of Medical Sciences, Poznań, Poland.
Pol Arch Med Wewn. 2011 Sep;121(9):287-95.
The results of recent studies suggest that there is a link between the presence of antibodies against C1q (anti-C1q Abs) and kidney involvement in systemic lupus erythematosus (SLE). However, it remains unclear whether the clinical symptoms of lupus nephritis (LN) may be associated with the presence of anti-C1q Abs in serum.
The aim of the study was to compare the prevalence and levels of anti-C1q Abs and antibodies against double-stranded DNA (anti-dsDNA Abs), circulating immune complexes binding C1q (CIC-C1q), as well as complement components C3 and C4 in the sera of patients with LN in relation to the clinical activity of SLE and symptoms of LN.
The study involved 48 patients with LN and 66 healthy controls. Anti-dsDNA Abs, anti-C1q Abs, and CIC-C1q levels were determined by immunoenzymatic methods, while C3 and C4 by immunoturbidimetry. SLE activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI).
Anti-dsDNA Abs, anti-C1q Abs, and CIC-C1q were detected in 77%, 60%, and 43.7% of the patients with LN, respectively. The prevalence and mean levels of anti-dsDNA and anti-C1q Abs were significantly higher in patients with active LN than in those with inactive LN or controls. The levels of C3 and C4 were significantly lower in active LN than in inactive LN or controls. In active LN, a positive correlation between anti-C1q and anti-dsDNA Abs was observed. In patients with detected anti-C1q Abs, microhematuria (59% vs. 16%, P = 0.003), urinary casts (28% vs. 8%, P = 0.02), and low levels of serum C3 (P = 0.03) and C4 (P = 0.01) were observed statistically significantly more often.
Simultaneous presence of hematuria and anti-C1q Abs may indicate an ongoing inflammatory process in the glomeruli in patients with SLE.
近期研究结果表明，抗C1q抗体（抗C1q Abs）的存在与系统性红斑狼疮（SLE）的肾脏受累之间存在关联。然而，狼疮性肾炎（LN）的临床症状是否可能与血清中抗C1q Abs的存在相关仍不清楚。
本研究旨在比较LN患者血清中抗C1q Abs、抗双链DNA抗体（抗dsDNA Abs）、结合C1q的循环免疫复合物（CIC-C1q）以及补体成分C3和C4的患病率和水平，与SLE的临床活动度和LN症状的关系。
本研究纳入了48例LN患者和66例健康对照。采用免疫酶法测定抗dsDNA Abs、抗C1q Abs和CIC-C1q水平，采用免疫比浊法测定C3和C4。使用系统性红斑狼疮疾病活动指数（SLEDAI）评估SLE活动度。
LN患者中抗dsDNA Abs、抗C1q Abs和CIC-C1q的检出率分别为77%、60%和43.7%。活动性LN患者中抗dsDNA和抗C1q Abs的患病率和平均水平显著高于非活动性LN患者或对照组。活动性LN患者的C3和C4水平显著低于非活动性LN患者或对照组。在活动性LN中，观察到抗C1q与抗dsDNA Abs之间呈正相关。在检测到抗C1q Abs的患者中，镜下血尿（59%对16%，P = 0.003）、尿沉渣（28%对8%，P = 0.02）以及血清C3（P = 0.03）和C4（P = 0.01）水平较低的情况在统计学上更为常见。
血尿和抗C1q Abs同时存在可能表明SLE患者肾小球存在持续的炎症过程。
