Zhao M H, Liu N, Zhang Y K, Wang H Y
Department of Nephrology, First Teaching Hospital, Beijing Medical University, PR China.
Nephrol Dial Transplant. 1998 Nov;13(11):2821-4. doi: 10.1093/ndt/13.11.2821.
ANCA have been found in patients with systemic lupus erythematosus (SLE); however, the prevalence of ANCA and their target antigens is still not certain. This study is to investigate the prevalence of ANCA and their target antigens in Chinese patients with lupus nephritis.
Ninety-five serum samples were collected from 95 renal-biopsy-proven lupus nephritis patients. Indirect immunofluorescence using ethanol-fixed leukocytes as substrate and ELISA using six highly purified known ANCA antigens as solid-phase ligands were performed. The specific ANCA antigens included proteinase 3, myeloperoxidase, bactericidal/permeability-increasing protein, human leukocyte elastase, cathepsin G, and lactoferrin. The prevalence of ANCA in patients with (n=65) and without (n=30) active renal pathological lesions was also compared to reveal whether ANCA correlates with disease activity.
(i) None of the sera recognized proteinase 3, myeloperoxidase, and human leukocyte elastase, and only one serum recognized bactericidal/permeability-increasing protein. The striking finding was that 59/95 (62.1%) sera recognized cathepsin G and the titres of some sera reached 1/3200. Eight of 95 sera (8.4%) recognized lactoferrin. (ii) The percentage of anti-cathepsin G antibody positive samples in patients with active renal lesions was significantly higher than in patients without active lesions (73.4 vs 36.7%, P<0.0001), whereas, anti-lactoferrin antibodies had no correlation with active renal lesions. (iii) By indirect immunofluorescence, only 22% of the 95 sera were ANCA positive.
Our results suggest that the majority of lupus nephritis patients have ANCA and that the major target antigens is cathepsin G. Anti-cathepsin G antibodies seem to be correlated with renal disease activity.
在系统性红斑狼疮（SLE）患者中已发现抗中性粒细胞胞浆抗体（ANCA）；然而，ANCA及其靶抗原的患病率仍不确定。本研究旨在调查中国狼疮性肾炎患者中ANCA及其靶抗原的患病率。
收集95例经肾活检证实为狼疮性肾炎患者的血清样本。采用以乙醇固定白细胞为底物的间接免疫荧光法和以六种高度纯化的已知ANCA抗原为固相配体的酶联免疫吸附测定（ELISA）法。特异性ANCA抗原包括蛋白酶3、髓过氧化物酶、杀菌/通透性增加蛋白、人白细胞弹性蛋白酶、组织蛋白酶G和乳铁蛋白。还比较了有（n = 65）和无（n = 30）活动性肾脏病理病变患者中ANCA的患病率，以揭示ANCA是否与疾病活动相关。
（i）所有血清均未识别出蛋白酶3、髓过氧化物酶和人白细胞弹性蛋白酶，仅1份血清识别出杀菌/通透性增加蛋白。显著的发现是，59/95（62.1%）份血清识别出组织蛋白酶G，部分血清的滴度达到1/3200。95份血清中有8份（8.4%）识别出乳铁蛋白。（ii）有活动性肾脏病变患者中抗组织蛋白酶G抗体阳性样本的百分比显著高于无活动性病变患者（73.4%对36.7%，P<0.0001），而抗乳铁蛋白抗体与活动性肾脏病变无关。（iii）通过间接免疫荧光法，95份血清中仅22%为ANCA阳性。
我们的结果表明，大多数狼疮性肾炎患者存在ANCA，主要靶抗原是组织蛋白酶G。抗组织蛋白酶G抗体似乎与肾脏疾病活动相关。
