Barlow K L, Tosswill J H, Parry J V, Clewley J P
Virus Reference Division, Central Public Health Laboratory, London, United Kingdom.
J Clin Microbiol. 1997 Nov;35(11):2846-53. doi: 10.1128/jcm.35.11.2846-2853.1997.
Over a 4-year period, the Roche Amplicor kit was used in a United Kingdom reference laboratory for the detection or confirmation of human immunodeficiency virus (HIV) type 1 infection, particularly in infants born to HIV-infected mothers. Of 408 specimens from adults and older children tested, the 122 seronegative specimens were all Amplicor negative. Of the 286 seropositive specimens, 268 were Amplicor positive. On the basis of these results, the Amplicor assay has a specificity of 100% and a sensitivity of 93.7%. In addition, for 247 specimens from infants and young children, serological results may not have been diagnostic because of placental transfer of maternal antibodies. Forty-eight were Amplicor positive, and of the 199 Amplicor-negative specimens, 19 were assumed to be false negative on the basis of clinical data, serological markers (including p24 antigen), and/or results for previous or follow-up specimens. This represents a sensitivity of 75% for the Amplicor test for specimens from patients under 2 years of age. Of these 37 false-negative specimens plus 2 specimens from other laboratories, 31 could be characterized by amplifying extracted material from them by an in-house nested gag PCR spanning the Amplicor target region. The amplicons were sequenced and found to represent subtypes A (35.5%), B (22.6%), C (22.6%), D (16.1%), and G (3.2%). False-negative results by the Amplicor assay may be ascribed to low-target copy number, the physical behavior of one primer (SK462), and sequence variation in the target region of the other primer (SK431).
在4年的时间里，罗氏Amplicor试剂盒被用于英国一家参考实验室检测或确认1型人类免疫缺陷病毒（HIV）感染，特别是检测感染HIV的母亲所生婴儿。在检测的408份成人及大龄儿童标本中，122份血清阴性标本的Amplicor检测结果均为阴性。在286份血清阳性标本中，268份Amplicor检测呈阳性。基于这些结果，Amplicor检测的特异性为100%，灵敏度为93.7%。此外，对于247份婴幼儿标本，由于母体抗体的胎盘转移，血清学结果可能无法用于诊断。48份Amplicor检测呈阳性，在199份Amplicor检测阴性的标本中，根据临床数据、血清学标志物（包括p24抗原）和/或之前或后续标本的检测结果，有19份被认为是假阴性。这表明Amplicor检测对2岁以下患者标本的灵敏度为75%。在这37份假阴性标本以及来自其他实验室的2份标本中，31份可以通过对其中提取的材料进行跨越Amplicor靶区域的内部巢式gag PCR扩增来进行特征分析。对扩增产物进行测序后发现，其代表的亚型有A（35.5%）、B（22.6%）、C（22.6%）、D（16.1%）和G（3.2%）。Amplicor检测出现假阴性结果可能归因于靶标拷贝数低、一种引物（SK462）的物理行为以及另一种引物（SK431）靶区域的序列变异。
