抗C1q抗体与系统性红斑狼疮疾病活动及狼疮肾炎的关系

目的研究抗C1q抗体与系统性红斑狼疮（systemic lupus erythematosus,SLE）疾病活动及肾损害的相关性。方法使用ELISA法测定93例初诊SLE患者和69例其他风湿性疾病患者及32名健康对照者血清中抗C1q抗体的浓度。同时记录SLE疾病活动指数（systemic lupus erythematosus Disease Activity Index,SLEDAI）、自身抗体和相关实验室指标。结果血清抗C1q抗体、抗dsDNA抗体、抗核小体抗体（anti-nucleosome antibodies,AnuA）,SLE组的阳性率分别为40.9%、62.4%和62.8%。血清抗C1q抗体阳性组患者的肾损害发生率（84.2%）明显高于阴性组（23.6%）。狼疮肾炎（lupus nephritis,LN）患者血清抗C1q抗体浓度（55.36±51.96）RU/ml及阳性率（71.1%）显著高于无肾炎表现的狼疮对照组（12.09±14.46）RU/ml,12.5%。无论患者有无肾损害,狼疮疾病活动患者抗C1q抗体浓度（62.46±50.29）RU/ml及阳性率（85.7%）显著高于疾病稳定的狼疮对照组（8.79±6.42）RU/ml,3.9%。而AnuA和抗dsDNA抗体只在伴有狼疮肾损害的疾病活动组即活动LN的阳性率（87.9%与50.0%）显著高于非活动LN对照组（66.7%与33.3%）。LN组抗C1q抗体、AnuA、抗dsDNA和抗Sm（Smith）抗体阳性率显著高于非LN组（71.1%与12.5%）,（77.8%与47.9%）,（57.8%与25.0%）,（31.1%与10.4%）。SLE疾病活动组抗C1q抗体、AnuA、抗dsDNA阳性率显著高于疾病稳定组（85.7%与3.9%）,（88.1%与41.2%）,（61.9%与17.6%）。活动LN抗C1q抗体、AnuA、抗dsDNA阳性率显著高于非活动LN（93.9%与8.3%）,（87.9%与50.0%）,（66.7%与33.3%）。活动LN组抗C1q抗体、AnuA、抗dsDNA及抗中性粒细胞胞质抗体（ANCA）阳性率显著高于其他SLE组（93.9%与13.1%）,（87.9%与48.3%）,（66.7%与26.7%）,（43.5%与8.5%）。结论血清抗C1q抗体能够反映SLE的疾病活动,并与SLE肾损害相关,是对活动性LN敏感的自身抗体。

Anti-C1q Antibodies in Systemic Lupus Erythematosus-relationship with Disease Activity and Renal Involvement

Objective To investigate the relation between the presence and concentration of anti-C1q antibodies （Ab） and disease activity and renal involvement in patients with systemic lupus erythematosus （SLE） compared to other connective tissue diseases.Methods Anti-C1q Ab were measured by enzyme-linked immunosorbant assay （ELISA） in 93 patients with SLE.As control groups we included 32 healthy blood donors and 69 diseased controls.Results Anti-C1q Ab were positive in 40.9%,anti-dsDNA Ab in 40.9% and anti-nucleosome antibodies （AnuA） in 62.8% of patients with SLE,respectively.The incidence of renal involvement in patients with positive anti-C1q Ab was higher than that in anti-C1q Ab negative group （84.2% vs 23.6%）.Lupus nephritis （LN） patients showed a significantly higher positive rate and serum levels of anti-C1q Ab than non-LN patients （55.36 ± 51.96） RU/ml vs （12.09 ± 14.46） RU/ml],（71.1% vs 12.5%）.The positive rate and serum levels of anti-C1q Ab was significantly higher in active patients compared with inactive patients （62.46 ± 50.29） RU/ml vs （8.79 ± 6.42） RU/ml],（85.7% vs 3.9%）.But both AnuA and anti-dsDNA Ab were only significantly higher between patients active nephritis and inactive nephritis （87.9% vs 50.0%）,（66.7% vs 33.3%）.The positive rate of anti-C1q Ab,AnuA,anti-dsDNA Ab and anti-Sm were significantly higher between patients with and without nephritis （71.1% vs 12.5%）,（77.8% vs 47.9%）,（57.8% vs 25.0%）,（31.1% vs 10.4%）.The positive rate of anti-C1q Ab,AnuA and anti-dsDNA Ab were significantly higher between patients with and without disease active （85.7% vs 3.9%）,（88.1% vs 41.2%）,（61.9% vs 17.6%）.The positive rate of anti-C1q Ab,AnuA and anti-dsDNA Ab in patients with active LN were significantly higher than those without active LN （93.9% vs 8.3%）,（87.9% vs 50.0%）,（66.7% vs 33.3%）.The positive rate of anti-C1q Ab,AnuA,anti-dsDNA Ab and antineutrophil cytoplasmic autoantibodies （ANCA） in patients with active LN were significantly higher than those with other SLE （93.9% vs 13.1%）,（87.9% vs 48.3%）,（66.7% vs 26.7%）,（43.5% vs 8.5%）.Conclusion Anti-C1q antibodies are closely related to the pathogenesis of SLE and LN.