Khanna Dhanita, Aggarwal Amita, Bhakuni Darshan S, Dayal Rajeshwar, Misra Ramnath
Department of Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
J Rheumatol. 2003 Jun;30(6):1248-52.
To study the prevalence and antigenic specificity of antineutrophil cytoplasmic autoantibodies (ANCA) in patients with systemic sclerosis (SSc).
Sera from 68 patients with SSc were screened for ANCA by indirect immunofluorescence (IIF) assay and for antibodies to myeloperoxidase (MPO) by ELISA. All sera positive for ANCA on IIF were analyzed for reactivity against antigenic targets other than MPO [bactericidal/permeability-increasing protein (BPI), cathepsin G, lysozyme, elastase, PR3, and lactoferrin]. Twenty-three sera negative for ANCA were also tested for antibodies to BPI and cathepsin G using ELISA.
The study included 33 patients with diffuse and 35 with limited SSc. ANCA was detected in 24 of the 68 sera (35.3%). In these 24 sera the antigenic targets were BPI in 14, cathepsin G in 13, and MPO in 8. Sera of 11 patients had reactivity against both BPI and cathepsin G. In sera, that were negative for ANCA, antibodies to BPI (4/23), cathepsin G (3/23), and MPO (1/44) were found in a small proportion of patients. Patients with antibodies to BPI had lower skin score, whereas no patient with antibodies to MPO had renal disease.
BPI and cathepsin G are the major antigenic targets of ANCA seen in patients with SSc. Patients with antibodies to BPI had lower skin scores.
研究系统性硬化症（SSc）患者抗中性粒细胞胞浆自身抗体（ANCA）的患病率及抗原特异性。
采用间接免疫荧光法（IIF）对68例SSc患者血清进行ANCA筛查，采用酶联免疫吸附测定（ELISA）检测髓过氧化物酶（MPO）抗体。对IIF检测ANCA阳性的所有血清分析其对MPO以外抗原靶点[杀菌/通透性增加蛋白（BPI）、组织蛋白酶G、溶菌酶、弹性蛋白酶、蛋白酶3（PR3）和乳铁蛋白]的反应性。还采用ELISA法对23例ANCA阴性血清检测BPI和组织蛋白酶G抗体。
该研究纳入33例弥漫性SSc患者和35例局限性SSc患者。68份血清中有24份（35.3%）检测到ANCA。在这24份血清中，抗原靶点为BPI的有14份，组织蛋白酶G的有13份，MPO的有8份。11例患者的血清对BPI和组织蛋白酶G均有反应性。在ANCA阴性的血清中，一小部分患者检测到BPI抗体（4/23）、组织蛋白酶G抗体（3/23）和MPO抗体（1/44）。有BPI抗体的患者皮肤评分较低，而有MPO抗体的患者均无肾脏疾病。
BPI和组织蛋白酶G是SSc患者中ANCA的主要抗原靶点。有BPI抗体的患者皮肤评分较低。
