Waléria-Aleixo A, Greco D B, Brindeiro R, Tanuri A
Laboratório de Imunologia e Biologia Molecular, Infectious Diseases Service and School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Arch Virol. 2008;153(8):1489-94. doi: 10.1007/s00705-008-0138-2. Epub 2008 Jul 4.
The I50V protease inhibitor (PI) resistance mutation was found in 87.4% of protease gene fragments sequenced from 199 nucleic acid isolates extracted using an NASBA virus load assay, performed between 1997 and 2001 in Brazil. This mutation is an amprenavir-related mutation, and at that particular time this PI was seldom used in Brazil. This mutation was found both in patients with and without therapeutic success. Q calibrators showed the PI resistance mutation I50V when directly amplified and sequenced from the 423-bp PCR product targeting protease gene. The majority of the patients' samples had a mixture of I50I and I50V; however, this artifact was nor seen when a 989-bp PCR product was used. These results show that RNA extracted using virus load kits need to be critically evaluated before being used in home-brew genotypic tests.
在1997年至2001年于巴西进行的一项研究中，采用核酸序列依赖性扩增（NASBA）病毒载量检测法从199份核酸分离物中提取的蛋白酶基因片段进行测序，结果发现87.4%存在I50V蛋白酶抑制剂（PI）耐药突变。该突变是与安普那韦相关的突变，而在那个特定时期，这种PI在巴西很少使用。在治疗成功和未成功的患者中均发现了这种突变。Q校准品在直接扩增并对靶向蛋白酶基因的423 bp PCR产物进行测序时显示出PI耐药突变I50V。大多数患者样本同时存在I50I和I50V；然而，当使用989 bp PCR产物时未观察到这种假象。这些结果表明，在用于自制基因分型检测之前，需要对使用病毒载量试剂盒提取的RNA进行严格评估。
