Universidade de São Paulo, Instituto de Medicina Tropical de São Paulo, Avenida Dr. Eneas de Carvalho Aguiar 470, São Paulo, Brazil.
J Clin Virol. 2010 May;48(1):6-10. doi: 10.1016/j.jcv.2010.02.020. Epub 2010 Mar 23.
JC virus (JCV), the causative agent of progressive multifocal leukoencephalopathy (PML), is classified in 8 different genotypes. Previous reports have suggested a positive association between specific genotypes and PML.
To compare genotypes and adaptive mutations of JCV strains from Brazilian AIDS patients with and without PML.
The VP1 region of JCV was amplified by polymerase chain reaction from cerebrospinal fluid samples from 51 patients with PML and from urine samples of 47 patients with AIDS without central nervous system disease. Genotyping was done by phylogenetic analysis. Amino acid replacement and selection pressures were also investigated.
JCV genotype frequency distributions showed that genotypes 2 (32.7%), 1 (26.5%) and 3 (23.5%) were the most prevalent. Genotype 1 had a positive association (p<0.0001) and genotype 3 showed an inverse association (p<0.001) with PML. A previously undescribed point mutation at residue 91 (L/I or L/V) and (L/P), non-genotype-associated, was found in 5/49 (10.2%) and 2/47 (4.3%) JCV sequences from PML and non-PML patients, respectively. This mutation was under positive selection only in PML patients. A previously described substitution of T-A in position 128 showed a significant difference between PML and non-PML cases (70% versus 16%, respectively, p<0.0005).
In Brazilian patients with AIDS, JCV genotype 1 showed a strong association with PML (p<0.0001) and JCV genotype 3 showed an inverse association with PML. The possible association of aminoacids substitution in residues 91 and 128 with PML in patients with AIDS must be further investigated.
JC 病毒（JCV）是进行性多灶性白质脑病（PML）的病原体，分为 8 种不同的基因型。先前的报告表明，特定基因型与 PML 之间存在正相关关系。
比较巴西 AIDS 患者伴或不伴 PML 的 JCV 毒株基因型和适应性突变。
采用聚合酶链反应（PCR）从 51 例 PML 患者的脑脊液样本和 47 例无中枢神经系统疾病的 AIDS 患者的尿液样本中扩增 JCV 的 VP1 区。通过系统发育分析进行基因分型。还研究了氨基酸替换和选择压力。
JCV 基因型频率分布显示，基因型 2（32.7%）、1（26.5%）和 3（23.5%）最为常见。基因型 1 与 PML 呈正相关（p<0.0001），基因型 3 与 PML 呈负相关（p<0.001）。在 5/49（10.2%）和 2/47（4.3%）来自 PML 和非 PML 患者的 JCV 序列中发现了以前未描述的残基 91 处的点突变（L/I 或 L/V）和（L/P），与基因型无关。该突变仅在 PML 患者中受到正选择。以前描述的位置 128 处的 T-A 取代在 PML 和非 PML 病例之间存在显著差异（分别为 70%和 16%，p<0.0005）。
在巴西 AIDS 患者中，JCV 基因型 1 与 PML 呈强相关（p<0.0001），JCV 基因型 3 与 PML 呈负相关。必须进一步研究氨基酸残基 91 和 128 处的取代与 AIDS 患者 PML 的可能关联。
