Virology Department, Saint-Louis Hospital, Assistance Publique-Hôpitaux de Paris, INSERM U941, Paris Diderot University, Sorbonne Paris Cité, Paris, France.
HIV Med. 2013 Feb;14(2):85-91. doi: 10.1111/j.1468-1293.2012.01039.x. Epub 2012 Sep 20.
The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping.
Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype.
No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA.
The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.
拉替拉韦（RAL）耐药进化的机制尚未阐明。由于 RAL 耐药的出现通常是由 N155H 突变引起的，我们评估了在 5 名长期接受 RAL 治疗失败且具有三种不同耐药谱的重度治疗患者中，循环 RNA 和存档 DNA 中少量 N155H 突变体的作用。
采用等位基因特异性聚合酶链反应（AS-PCR）检测 5 名感染 HIV-1 B 亚型的患者纵向储存的血浆和全血样本中 N155H 突变体，这些患者在 RAL 为基础的方案之前、期间和之后进行了检测。
在 5 名患者中，未通过 AS-PCR 在基线和 RAL 停药后的任何血浆或全血样本中检测到少量 N155H 突变体。在 RAL 失效期间，在显示 N155H 途径的 3 名患者中检测到突变 N155H 的不同水平，而在一名患者中当选择双突变 Q148H+G140S 时，其水平逐渐下降。在两名具有 Q148H 耐药途径的患者中，无论是在病毒 RNA 还是 DNA 中，均未通过 AS-PCR 鉴定出 N155H 变体。
从少数到多数存在的 N155H 突变与三种与 RAL 相关的耐药谱没有关系，这表明该突变体可能不会在确定不同耐药谱中起作用。此外，预先存在的 N155H 非常罕见，如果在 RAL 失效时被选择，那么在 RAL 停药后，N155H 突变体很快就会消失。
