Thakral B, Saluja K, Sharma R R, Marwaha N
Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
J Postgrad Med. 2006 Apr-Jun;52(2):106-9.
HIV/AIDS pandemic brought into focus the importance of safe blood donor pool.
To analyze true seroprevalence of HIV infection in our blood donors and devise an algorithm for donor recall avoiding unnecessary referrals to voluntary counseling and testing centre (VCTC).
39,784 blood units were screened for anti-HIV 1/2 using ELISA immunoassay (IA-1). Samples which were repeat reactive on IA-1 were further tested using two different immunoassays (IA-2 and IA-3) and Western blot (WB). Based on results of these sequential IAs and WB, an algorithm for recall of true HIV seroreactive blood donors is suggested for countries like India where nucleic acid testing or p24 antigen assays are not mandatory and given the limited resources may not be feasible.
The anti-HIV seroreactivity by repeat IA-1, IA-2, IA-3 and WB were 0.16%, 0.11%, 0.098% and 0.07% respectively. Of the 44 IA-1 reactive samples, 95.2% (20/21) of the seroreactive samples by both IA-2 and IA-3 were also WB positive and 100% (6/6) of the non-reactive samples by these IAs were WB negative. IA signal/cutoff ratio was significantly low in biological false reactive donors. WB indeterminate results were largely due to non-specific reactivity to gag protein (p55).
HIV seroreactivity by sequential immunoassays (IA-1, IA-2 and IA-3; comparable to WHO Strategy-III) prior to donor recall results in decreased referral to VCTC as compared to single IA (WHO Strategy-I) being followed currently in India. Moreover, this strategy will repose donor confidence in our blood transfusion services and strengthen voluntary blood donation program.
艾滋病疫情使安全献血者群体的重要性受到关注。
分析我国献血者中艾滋病毒感染的实际血清流行率，并设计一种献血者召回算法，避免不必要地转介至自愿咨询检测中心（VCTC）。
采用酶联免疫吸附测定法（IA - 1）对39784个血液单位进行抗HIV 1/2筛查。对IA - 1重复反应性的样本，进一步使用两种不同的免疫测定法（IA - 2和IA - 3）及免疫印迹法（WB）进行检测。基于这些连续免疫测定法和WB的结果，针对印度等国家提出一种召回真正艾滋病毒血清反应性献血者的算法，在这些国家核酸检测或p24抗原检测并非强制要求，且鉴于资源有限可能不可行。
重复IA - 1、IA - 2、IA - 3和WB检测的抗HIV血清反应性分别为0.16%、0.11%、0.098%和0.07%。在44个IA - 1反应性样本中，IA - 2和IA - 3均为血清反应性的样本中有95.2%（20/21）WB也呈阳性，而这些免疫测定法检测为非反应性的样本中有100%（6/6）WB呈阴性。生物学假反应性献血者的IA信号/临界值比率显著较低。WB不确定结果主要是由于对gag蛋白（p55）的非特异性反应。
与印度目前采用的单一免疫测定法（世卫组织策略 - I）相比，在召回献血者之前采用连续免疫测定法（IA - 1、IA - 2和IA - 3；等同于世卫组织策略 - III）检测艾滋病毒血清反应性，可减少转介至VCTC的情况。此外，该策略将增强献血者对我们输血服务的信心，并加强自愿献血计划。
