不同人群血清SARS冠状病毒抗体检测及其意义

目的　通过对不同人群SARS冠状病毒IgG抗体 (SARSCoVIgG)检测 ,明确该抗体对SARS的诊断意义。方法　采用酶联免疫法 (EIA)、间接荧光法 (IFA)和免疫印迹法 (WB)检测抗 SARSCoVIgG。结果　对 117例临床确诊为SARS患者的 336份系列血清检测表明 ,SARS病人血清抗 SARSCoVIgG最早于发病后第 9天阳转 ,其阳性率随病程延长而上升 ,于发病后 5～ 9、10～ 14、15～ 19、2 0～2 4和 2 5d以上抗 SARSCoVIgG阳性率分别为 12 .5 % (1/8)、73.9% (17/2 3)、91.5 % (43/47)、96 .6 %(5 7/5 9)和 10 0 % (198/198)。应用EIA初筛 12 2 3名非SARS人群 (包括 36 7名在SARS病房工作 1个月以上的医务人员 ,4 3名在生活中与临床确诊的SARS病人有密切接触史者 ,以及 813例未暴露于SARSCoV人群 ) ,其中 2 8名为抗 SARSCoVIgG弱阳性 (A <0 .5 ) ,但用 2种IFA和WB检测均为阴性 ,说明EIA初筛为假阳性。结论　应用EIA检测抗SARSCoVIgG有助于中晚期SARS病人的诊断。对EIA初筛为抗 SARSCoVIgG弱阳性的标本 (A <0 .5 ) ,应用其他方法如IFA和WB检测 ,以排除假阳性。

Detection of anti-SARS CoV IgG antibody in sera of different populations and its significance

Objective To evaluate the significance of the anti-SARS CoV IgG in sera of different populations, using enzyme linked immunosorbent assay (EIA). Methods EIA, indirect fluorescence assays (IFA) and Western blot (WB) were used for the detection of the anti-SARS CoV IgG in serum. Results Dynamics of the anti-SARS CoV IgG were studied in 336 serial sera from 117 clinically diagnosed SARS patients. The antibody was first detected on the 9 th day after onset of the disease. The positive rates of the anti-SARS CoV IgG increased with the course of the illness, i.e. 12.5%(1/8), 73.9%(17/23), 91.5%(43/47), 96.6%(57/59) and 100%(198/198) respectively, on 5-9, 10-14, 15-19, 20-24 and 25 days after onset. Of 1?223 non-SARS individuals including 367 healthy workers working in SARS wards for more than 1 month, 43 close contacts with clinically diagnosed SARS patients and 813 persons without exposure to SARS CoV,28 were anti-SARS CoV IgG weak positive with the A value less than 0.5 by EIA screening. The antibody was negative in these 28 sera when re-tested by IFA and/or WB, indicating false positivity by EIA. Conclusion The detection of anti-SARS CoV IgG by EIA is useful for diagnosis of SARS patients at the middle and late phases of the disease. The specimens with weak positivity ( A value less than 0.5)of anti-SARS CoV IgG screened by EIA should be retested using IFA and/or WB to rule out the false reactivity.