HIV抗體篩檢試驗陽性與西方墨點法確認試驗結果之差異探討

Inconsistency of HIV Ab Screening Test and Confirmatory Western Blot Assay

蘇承瑜(Cheng-Yu Su) ； 曹國倩(Kuo-Chien Tsao) ； 黃瓊瑰(Chung-Guei Huang) ； 李佳縉(Chia-Chin Li) ； 邢福柳(Hock-Liew Eng)

《Journal of Biomedical & Laboratory Sciences》 22卷4期 (2010/12) Pp. 134-140

https://doi.org/10.30046/JBLS.201012.0003

摘要

人類免疫缺乏病毒（Human Immunodeficiency Virus，HIV，俗稱愛滋病毒）的檢驗可分爲篩檢及確認試驗，篩檢試驗敏感性較高但會有僞陽性的可能，需要使用確認試驗做證實。本次研究的重點即在分析篩檢試驗陽性案例與確認試驗結果之差異。分析對象爲本實驗室2002年至2008年血液經AxSYM HIV抗體篩檢試驗結果陽性且再進行HIV-1西方墨點法(Western Blot)者共205例。分析結果發現，205例中西方墨點法陽性結果共177例(86.4%)，HIV抗體S/CO值皆在9.0以上；不確定結果有6例(2.9%)，S/CO值4例在8.0以上，2例在4.0以下；陰性結果共22例(10.7%)，S/CO值分佈幾乎集中在S/CO4.0以下。這些結果顯示AxSYM HIVS/CO值在1.0-4.0間，兩種方法結果不一致的機率很高。分析發現這些不一致之病患中所罹患的疾病包括：肝臟疾病（肝炎、肝癌、疫苗接種）、自體免疫疾病、惡性腫瘤、器官移植、洗腎患者及愛滋病患之新生兒、懷孕婦女、藥癮者等，是否與這些疾病有關，需要更多的研究加以證實；另一方面，針對高危險群者，若在感染初期，病毒抗體濃度太低，亦會造成2種方法不一致的現象，此時病患應持續追蹤進行複驗。

關鍵字

HIV ； 篩檢試驗 ； 西方墨點法確認試驗 ； 僞陽性

並列摘要

Objective: The human immunodeficiency virus (HIV) laboratory tests comprise screening tests and confirmatory tests. Although the screening method is relatively more sensitive, it requires a subsequent confirmatory test to prevent the possibility of false positive results. This study aimed to analyze the discrepancy between the results of screening and confirmatory tests. From 2002 to 2008, a total of 205 cases that were positive in the AxSYM HIV antibody screening test and had been performed the HIV-1 Western Blot confirmatory test in our laboratory were collected for further analysis. Among them, 177 (86.4%) cases were positive in the western blot analysis, with the HIV Ab S/CO values all larger than 9.0; 6 (2.9%) cases had indeterminate results, with the S/CO values over 8.0 in 4 cases and below 4.0 in 2 cases. The remaining 22 (10.7%) cases were negative in the western blot analysis, and the S/CO values were almost all smaller than 4.0. These results suggested that inconsistency was likely to occur in specimens showing AxSYM HIV S/CO values in the range between 1.0 and 4.0. This phenomenon was usually found in patients with liver diseases (hepatitis, liver cancer, after vaccination), autoimmune disease, malignant tumor, organ transplantation, hemodialysis patients, pregnant women, the drug-addict, and infants born to mothers with HIV, etc. Whether the inconsistent results were related to these disease conditions will need further studies. On the other hand, the discrepancy could occur during the early stage of infection when the level of viral antibodies remained too low to be detected. For those high-risk patients, if such inconsistence is occurred, a subsequent follow-up examination is suggested.

並列關鍵字

HIV ； screening test ； confirmatory Western Blot assay ； false positive