Recombinant phenotyping of cytomegalovirus sequence variants detected after 200 or 100 days of valganciclovir prophylaxis.
Recombinant phenotyping of cytomegalovirus sequence variants detected after 200 or 100 days of valganciclovir prophylaxis.
复制标题
缬更昔洛韦预防 200 或 100 天后检测到的巨细胞病毒序列变异的重组表型。
DOI：
10.1097/tp.0b013e3181fdd9d2
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发表时间：
2010
期刊：
影响因子：
6.2
通讯作者：
Elston,Robert
中科院分区：
文献类型：
--
作者：
Chou,Sunwen;Marousek,Gail;Boivin,Guy;Goyette,Nathalie;Farhan,Mahdi;Ives,JaneAL;Elston,Robert
背景：在一项III期对照试验中，在318名巨细胞病毒D+/R−肾移植受者中，200天和100天的万乃昔洛韦预防相比，在病毒突破期间检测到已知的更昔洛韦耐药突变(n=3)。此外，还观察到了许多其他病毒序列变异，这些变异对更昔洛韦的耐药性具有未知的意义。方法：通过重组将编码UL97激酶或UL54 DNA聚合酶基因中单个氨基酸替换的序列转移到克隆的巨细胞病毒实验室株中，然后对所得到的病毒进行基于报告的产量减少表型分析。结果：共检测到26个未知的氨基酸替换，其中UL97和UL54分别为2和24。选择200天ARM中的所有10个替换和100天ARM中17个替换中的9个(基于位置和保守性的优先顺序)进行表型分析；在两个子集中都检测到一个替换。10个200天替代方案中的9个和9个100天替代方案中的8个产生了结果，没有替代方案显示更昔洛韦的敏感性显著降低。由于病毒活性差，UL54中剩余的两个氨基酸替换均未被评估。结论：与预防100天组相比，预防200天组以前未确定的病毒基因型的表型评估没有证据表明更昔洛韦耐药基因的发生率增加。
Background.In a phase III controlled trial IMproved Protection Against Cytomegalovirus in Transplantation (IMPACT) comparing 200 with 100 days of valganciclovir prophylaxis in 318 cytomegalovirus D+/R− kidney transplant recipients, an equal number of patients (n= 3 per arm) had known ganciclovir resistance mutations detected during viral breakthrough. In addition, many other viral sequence variants were observed that were of unknown significance for ganciclovir resistance. Recombinant phenotyping was performed to determine whether the previously uncharacterized genotypic changes affected ganciclovir susceptibility, especially in those receiving the longer duration of prophylaxis.Methods.Sequences encoding individual amino acid substitutions in the UL97 kinase or UL54 DNA polymerase gene were transferred by recombination into a cloned cytomegalovirus laboratory strain, followed by reporter-based yield reduction phenotypic assay of the resulting virus for ganciclovir susceptibility.Results.Twenty-six uncharacterized amino acid substitutions were detected, 2 in UL97 and 24 in UL54. All 10 substitutions in the 200-day arm and 9 of 17 substitutions in the 100-day arm (prioritized based on location and conservation) were selected for phenotyping; one substitution was detected in both subsets. Results were generated for nine of ten 200-day and eight of nine 100-day substitutions, with no substitution demonstrating a significant reduction in ganciclovir susceptibility. The two remaining amino acid substitutions, both in UL54, were not evaluated because of poor viral viability.Conclusion.Phenotypic evaluation of previously uncharacterized viral genotypes in the 200-day valganciclovir prophylaxis group showed no evidence of an increased incidence of genotypic ganciclovir resistance when compared with those in the 100-day prophylaxis group.