抗核小体抗体、抗C1q抗体和抗双链DNA抗体在狼疮肾炎诊断中的意义

目的：通过抗核小体抗体、抗C1q抗体和抗双链DNA（dsDNA）抗体检测，观察3种抗体阳性的狼疮肾炎（LN）患者实验室检查和临床特征，阐明系统性红斑狼疮（SLE）并发LN的危险因素及3种抗体在LN诊断中的意义。方法：选择SLE患者120例，其中LN组60例，非LN组60例，回顾性分析2组患者抗核抗体谱及抗C1q抗体的差异；比较LN组患者抗核小体抗体、抗C1q抗体和抗dsDNA抗体3种抗体阳性的LN患者（三阳性LN组）和非抗体阳性的LN患者（非三阳性LN组）的临床表现及实验室检查的差异。结果：LN组患者抗C1q抗体阳性率为40.00%，非LN组患者抗C1q抗体阳性率为21.67%，2组患者抗C1q抗体阳性率比较差异有统计学意义（χ²=4.728，P=0.03）；LN组患者抗dsDNA抗体阳性率为66.67%，非LN组患者抗dsDNA抗体阳性率为46.67%，2组患者抗dsDNA抗体阳性率比较差异有统计学意义（χ²=4.887，P=0.027）；LN组患者抗核小体抗体阳性率为58.33%，非LN组患者抗核小体抗体阳性率为40.00%，2组患者抗核小体抗体阳性率比较差异有统计学意义（χ²=4.034，P=0.045）；其余抗体U1-snRNP、SmD1、Jo-1、SSA/Ro60kD、SSA/Ro52kD、SSB、scl-70、CENP-B和P0抗体阳性率组间比较差异均无统计学意义（P>0.05）。三阳性LN组与非三阳性LN组患者年龄及免疫球蛋白、C反应蛋白（CRP）、血沉、白细胞和血小板检测结果比较差异均无统计学意义（P>0.05），三阳性LN组患者补体C3、补体C4和血红蛋白水平较非三阳性LN组降低（P<0.05）。三阳性LN组和非三阳性LN组患者不同临床症状发生率比较差异无统计学意义（P>0.05）。结论：抗核小体抗体、抗C1q抗体和抗dsDNA抗体是SLE并发LN的危险因素，三抗体阳性可提高LN的诊断率，三阳性LN组患者补体和血液系统方面损害更严重，肾疾病活动度更高。

Significance of anti-nucleosome antibody,anti-C1q antibody and anti-double stranded DNA antibody in diagnosis of lupus nephritis

Objective:To investigate the clinical and laboratory characteristics of lupus nephritis(LN) patients by detecting the anti-nucleosome antibodies, anti-C1q antibodies and anti-double stranded antibodies(anti-ds DNA), and to clarify the risk factors of LN in the patients with systemic lupus erythematosus(SLE),and the significance of three kinds of antibodies in diagnosis of LN.Methods:A total of 120 SLE patients were selected and divided into LN group(n=60) and non-LN group(n=60).The ANAS data of 120 patients were retrospectively analyzed,the levels of anti-C1q antibodies were measured.The clinical symptoms and laboratory data of the patients with positive anti-dsDNA,-nucleosome and-C1q antibodies (3-pos group)and negative three kinds of antibodies(non 3-pos group) were analyzed in LN group.Results:The positive rate of anti-C1q antibody of the patients in LN group (40.00%) was higher than that in non-LN group (21.67%) (χ2=4.728, P=0.03).The positive rate of anti-dsDNA antibody in LN group was 66.67%, and it was 46.67% in non-LN group;the positive rates of the patients had significant difference between two groups (χ2=4.887, P=0.027).The positive rate of anti-nucleosome antibody in LN group was 58.33%, and it was 40.00% in non-LN group;the positive rates of the patients had significant difference between two groups (χ2=4.034, P=0.045).The positive rates of U1-snRNP, SmD1 and other antibodies Jo-1, SSA/Ro60kD, SSA/Ro52kD, SSB, ScL-70, CENP-B,and P0 had no significant differences between two groups(P>0.05).The levels of C3 and C4 and hemoglobinin of the patients in 3-pos group were higher than those innon 3-pos group (P<0.05);the age,the levels of immunoglobulin protein and C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), white blood cell (WBC) and platelet had no statistically significant differences between 3-pos and non 3-pos groups(P>0.05).The clinical symptoms were not statistically significant in 3-pos and non 3-pos groups (P>0.05).Conclusion:The anti-nucleosome, anti-C1q and anti-dsDNA antibodies are the risk factors of SLE complicated with LN;the positive antibodies can improve the diagnostic rate of LN.The 3-pos patients have more severe damage in complements and blood system with higher renal disease activities.