免疫印迹法检测HIV抗体出现假阳性的结果

A Report of False-positive in HIV Western Blot Test

2007年4月,烟台国际旅行卫生保健中心采用ELISA法对出入境人员进行艾滋病感染初筛时,发现1份HIV抗体检测结果为强阳性血清。随即将阳性血清送山东国际旅行卫生保健中心采用ELISA法复检,结果仍为强阳性;采用免疫印迹法(WB)进行确认,结果出现gp160、p24双条带。然而在对受检者进行流行病学调查时,其强烈否认有高危性行为,怀疑检测结果的可靠性。随后,阳性血清被送往北京国际旅行卫生保健中心艾滋病确证中心实验室采用免疫印迹法进行疑难确证,结果同样出现gp160、p24双条带。进一步用核酸定量检测(NASBA)进行HIV载量检测,结果为阴性。因此,建议作为HIV抗体阴性不确定进行随访。后经1年的多次随访检测,最终排除了其HIV感染。上述情况表明,对WB检测结果仅出现gp160和p24条带的样本直接判定为阳性具有一定的风险,必须结合核酸检测等辅助检测方法和流行病学调查结果综合考虑,艾滋病实验室在出具检测结果报告时,一定要慎重。

In April 2007,Yantai International Travel Healthcare Center found a strong positive ELISA result during HIV-1 screening test for exit-entry persons.Then,the serum was rechecked by Shandong International Travel Healthcare Center,the result also showed strong positive in ELISA test.Moreover,Western Blot（WB） confirmatory test exhibited bands at gp160 and p24,which meets the criteria for a HIV-1 positive.However,in our epidemiological study,the respondent strongly denied any high-risk behaviors related to HIV transmission. Therefore, the sample was sent to the central confirmatory HIV laboratory in Beijing International Travel Healthcare Center for a further validation. WB test showed the same reaction pattern of two bands. Additionally, NASBA test for HIV-1 nucleic acid was negative. So it was suggested that the result was temporarily judged as HIV-1 indeterminate and a regular follow-up test should be made in order to reach the final conclusion. As a result, HIV-1 infection was finally excluded after 3 times follow-up antibody tests at 3, 6 and 12 months. This case indicates that HIV-1 positive judgment based on the presence of just gpl60 and p24 two bands has some risk of false-positive, especially in the case without epidemiological data support. Epidemiological investigation and viral nucleic acid test may be very helpful for the comprehensive consideration. Thus, the HIV test laboratory must be careful with the conclusion in this condition.