A组β溶血性链球菌脂磷壁酸抗体在风湿热诊断中的意义

Significance of antibody to group A streptococcal lipoteichoic acid in diagnosis of rheumatic fever

目的 探讨A组 β溶血性链球菌 (乙链菌 )脂磷壁酸 (LTA)抗体在风湿热诊断中的意义。方法 用从A组乙链菌中提取的LTA作为抗原 ,采用斑点酶联免疫吸附测定 (ELISA)法检测血清中的LTA抗体。结果 ①风湿性心脏炎组LTA IgG抗体滴度水平高于静止期风湿性心脏病组、病毒性心肌炎组、非风湿性心脏瓣膜病组、其他关节炎组的滴度水平 ;②活动期风湿热患者LTA IgG抗体阳性率 (6 4 % )高于对照组的阳性率 ;③风湿性心脏炎患者的LTA IgG抗体阳性率与外周血淋巴细胞促凝血活性 (PCA)、抗链球菌壁多糖抗体 (ASP)、抗DNAse B、血沉、C反应蛋白的阳性率相接近 ,高于抗链球菌溶血素O (ASO)的阳性率。

Objective To evaluate the significance of the antibody to Group A streptococcal lipoteichoic acid in the diagnosis of rheumatic fever.Methods A new technique for extracting and purifying lipoteichoic acid (LTA) was employed,and antibodies to LTA of group A Streptococcus (GAS) were examined by dot ELISA.Results ① The levels of LTA IgG antibodies of rheumatic carditis patients were higher than those of patients with inactive rheumatic heart disease,viral myocarditis,non rheumatic valvular disease,non rheumatic arthritis and laryngopharynx infection.The levels of LTA IgG antibodies of acute rheumatic arthritis patients were higher than those of non rheumatic arthritis patients.② The positive rate of LTA IgG antibodies in patients with active rheumatic fever (55%) was higher than that in controls (13%) ( P <0 05).③ Comparisons were made among the results of LTA and other laboratory examinations in patients with rheumatic carditis.It was found that the differences were of no statistical significance among the positive rates of LTA IgG antibodies,PCA (procoagulant activity),ASP (antibodies to streptococcal polysaccharide),anti DNAse B,ESR and CRP.The positive rate of LTA IgG antibodies was higher than that of ASO.Conclusion ① It shows a rather high sensitivity of LTA IgG in the diagnosis of the disease.② LTA IgG antibodies have certain specificity in the diagnosis of RF.