卡介苗对结核分枝杆菌IFN-γ酶联免疫斑点检测法的影响

Evaluation the impact of BCG on the mycobacterium tuberculosis specific IFN-γ elispot assay

目的探讨卡介苗(BCG)对结核分枝杆菌IFN-γ酶联免疫斑点(简称Elispot)检测影响,评价Elispot检测在诊断结核分枝杆菌潜伏感染的价值。方法对98例某高校学生同时进行Elispot检测和PPD皮试,其中27例PPD皮试结果和Elis-pot检测均为阴性的受试者进行卡介苗接种。结果 98例受试者中,48例PPD皮试阳性,13例Elispot检测阳性,两种检测结果比较差异有统计学意义。对上述27例受试者接种BCG后PPD皮试结果全转为阳性,Elispot检测仍为阴性。在BCG接种前后,ESAT-6和PoolA作用下IFN-γ分泌水平均无差异;但在BCG作用下,BCG接种后IFN-γ分泌水平显著高于接种前。结论 Elis-pot检测体外IFN-γ应答反应不受卡介苗接种影响,在诊断结核分枝杆菌潜伏感染的价值优于PPD皮试。

Objective To investigate the impact of BCG on mycobacterium tuberculosis specific IFN-γ Elispot assay,and evaluate the application of interferon-gamma（IFN-γ）measurement on diagnosis of latent mycobacterium tuberculosis infection by using in-house elispot assay.Methods 98 subjects from high school in Shenzhen,were accepted the in-house elispot assay and PPD skin test.27 cases whose results of PPD skin test and in-house were both negative were received the BCG vaccinated.Results 48 subjects were positive responses to PPD skin test among the 98 subjects and 13 subjects were positive responses to in-house Elipot assay.The comparative study indicated that there was statistical difference between the result of in-house elispot assay and PPD skin test（χ^2=27.2222,P〈0.001）.All of the 27 subjects changed to positive result in PPD skin test,but were still negative result in the in-house Elispot assay.Before and after the BCG vaccinate,there was no difference of the level of IFN-γ response to the ESAT-6 and Pool A,respectively（P〉0.05,P〉0.05）.But there was significantly different of the level of IFN-γ response to BCG（P〈0.001）.Conclusion It demonstrates that there is no impact of BCG vaccinated on the mycobacterium tuberculosis specific IFN-γ elispot assay,which is better than the PPD skin test for screen of latent M.tb infection and it is available to screen of latent M.tb infection.