Laboratório de Virologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, Sao Paulo, Brasil.
Divisão de Moléstias Infecciosas e Parasitárias, do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brasil.
J Med Virol. 2019 Jun;91(6):1136-1141. doi: 10.1002/jmv.25409. Epub 2019 Feb 4.
BK virus is the causative agent of polyomavirus-associated nephropathy, a major cause of kidney transplant failure affecting 1%-10% of recipients. Previous studies that investigated the viral source on the kidney recipient pointed that the donor is implicated in the origin of human polyomavirus BK (BKPyV) infection in recipients, but giving the low genetic variability of BKPyV this subject is still controversial. The aim of this study was to determine if BKPyV replicating in kidney recipients after transplantation is always originated from the donor. Urine and blood samples from 68 pairs of living donors and kidney recipients who underwent renal transplantation from August 2010-September 2011 were screened for BKPyV by real time polymerase chain reaction. Only three recipients presented viremia. When both donors and recipients were BKPyV positive, a larger fragment of VP1 region was obtained and sequenced to determine the level of similarity between them. A phylogenetic tree was built for the 12 pairs of sequences obtained from urine and high level of similarity among all sequences was observed, indicating that homology inferences for donor and recipient viruses must be cautiously interpreted. However, a close inspection on the donor-recipient pairs sequences revealed that 3 of 12 pairs presented considerably different viruses and 4 of 12 presented mixed infection, indicating that the source of BKPyV infection is not exclusively derived from the donor. We report that about 60% of the renal recipients shed BKPyV genetically distinct from the donor, confronting the accepted concept that the donor is the main source of recipients' infection.
BK 病毒是多瘤病毒相关性肾病的病原体，是导致 1%-10%肾移植受者移植肾失功的主要原因。既往研究表明，在受者中，供者是人类多瘤病毒 BK（BKPyV）感染的来源，但由于 BKPyV 的遗传变异性较低，这一观点仍存在争议。本研究旨在确定移植后肾移植受者中复制的 BKPyV 是否始终来源于供者。对 2010 年 8 月至 2011 年 9 月期间接受肾移植的 68 对活体供者和肾移植受者的尿液和血液样本进行了实时聚合酶链反应检测 BKPyV。仅 3 例受者出现病毒血症。当供者和受者均为 BKPyV 阳性时，获得了更大的 VP1 区片段并进行测序，以确定它们之间的相似性水平。对从尿液中获得的 12 对序列构建了系统进化树，所有序列均显示出高度相似性，表明对供者和受者病毒的同源性推断必须谨慎解释。然而，对供者-受者序列的仔细检查显示，12 对中有 3 对存在明显不同的病毒，4 对存在混合感染，表明 BKPyV 感染的来源并非完全来自供者。我们报告称，约 60%的肾移植受者排出的 BKPyV 在遗传上与供者不同，这与供者是受者感染的主要来源的公认概念相矛盾。
