间接免疫荧光抗体试验在传染性非典型肺炎诊断中的应用

The application of indirect immuno-fluorescence assay in the diagnosis of severe acute respiratory syndrome

目的 评价应用间接免疫荧光抗体试验 (IFA)在传染性非典型肺炎 [严重急性呼吸综合征 (SARS) ]诊断中的可靠性 ,探讨SARS患者发病后血清抗体在体内的产生规律。方法 采用IFA方法检测不同发病时间的临床确诊SARS病例、疑似病例和其他人群的血清SARS病毒抗体 ,同时对每一个研究对象采用调查表进行一般情况调查。结果 在发病 10天内 ,SARS患者血清IgG阳性率为 5 5 .1%,IgM阳性率为16 .3 %;发病 10天后SARS患者IgG阳性率达89.8%,IgM阳性率达6 5 .3%;发病 2 5天以后SARS患者IgG、IgM阳性率均为90 .9%。对发病时间与抗体阳性率采用趋势χ2 检验 ,结果显示SARS患者血清IgG、IgM抗体阳性率随着发病时间而上升 (IgG趋势检验χ2 =16 .376 ,P =0 .0 0 0 0 5 ;IgM趋势检验χ2 =2 8.736 ,P =0 .0 0 0 0 0 )。IFA法用于检测SARS患者发病 10天后血清抗体 ,结果显示灵敏度、特异度及与临床诊断的符合率均在 90 %以上。结论 IFA法适于SARS发病 10天后作为实验室辅助诊断方法。

Objective To explore the temporal profile of serum antibody against coronavirus in patients with severe acute respiratory syndrome (SARS), and to evaluate the reliability of indirect immuno-fluorescence assay (IFA) in the diagnosis of SARS. Methods Clinically confirmed SARS patients, suspected SARS patients, and controls were included in the study. IFA was used to detect the serum antibody against SARS coronavirus. General information about the subjects was collected using a standard questionnaire. Results The positive rates of specific IgG and IgM against SARS virus within 10 days after onset of the disease were 55.1% and 16.3% respectively and then increased up to 89.8% for IgG and 65.3% for IgM. After 25 days of the onset of the disease, 90.9% patients became positive for both IgG and IgM. Results from chi-square for trend test revealed that the positive rates of both IgG and IgM increased with time (χ2 for trend = 16.376, P = 0.000 05 for IgG; χ2 for trend= 28.736, P = 0.000 00 for IgM). Sensitivity, specificity and agreement value of IFA regarding the diagnosis of SARS were all higher than 90%. Conclusion IFA can be used to assist diagnosis of SARS after 10 days of the onset of desease.