Ku抗原的提取及其抗体的检测

目的 测定本组自身免疫性结缔组织疾病（ＣＴＤｓ）患者中抗Ｋｕ抗体的阳性率。方法 制备兔腺丙酮粉，进而提取Ｋｕ抗原，采用免疫双扩散法检测４３８份ＣＴＤｓ和５０份正常对照血清中的抗Ｋｕ抗体。结果 自制的Ｋｕ抗原与标准Ｋｕ抗血清免疫双扩散出现清晰的沉淀线。４８８份血清中，抗Ｋｕ抗体阳性率２．５％（１２／４８８），其中皮肌炎为２．２％（１／４５），弥漫型系统性硬化症为３．４％（２／５８），系统性硬化症并多

Extraction of Ku antigen and anti-Ku antibody assay in various autoimmune connective tissue diseases

Objectives To extract Ku antigen and to detect anti Ku antibody in connective tissue diseases (CTDs).Methods Ku antigen was prepared from rabbit thymus acetone powder. Anti Ku antibodies were tested in 50 normal controls and 438 patients with CTDs by double immunodiffusion . Results The precipitin line developed between the antigen and the standard anti Ku serum. Among sera of 438 patients with CTDs and 50 healthy adults, the positive rate of anti Ku antibodies was 2.5% (12/488). The positive rate of anti Ku antibodies was 2.2% (1/45) in dermatomyositis, 3.4% (2/58) in diffuse systemic sclerosis, and 60.0% (9/15) in systemic sclerosis polymyositis (SSc PM) overlap syndrome respectively. One hundred patients with systemic lupus erythematosus, 70 patients with rheumatoid arthritis, 40 patients with primary Sjogren syndrome, 20 patients with mixed connective tissue disease, 30 patients with undifferentiated connective tissue disease, 25 patients with other CTDs and 50 normal controls showed negative results. The specificity of anti Ku antibodies for diagnosis of SSc PM was 99.4%.Conclusion The anti Ku antibody is relatively specific for systemic sclerosis polymyositis overlap connective tissue disease.