BK virus salivary shedding and viremia in renal transplant recipients

Abstract Objectives: This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia. Material and Methods: We have conducted a cross-sectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman's correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients. Results: The mean age of the study group was 51.11±12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80±6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86±5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman's correlation coefficient=0.193). Conclusion: The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication.

【摘要】研究目的：本研究旨在验证肾移植受者唾液中是否存在BK多瘤病毒（polyomavirus BK, BKPyV），并探讨其与血液病毒血症的相关性。
材料与方法：本研究为横断面研究，纳入126名肾移植受者作为研究样本。从上述患者中采集唾液样本126份、血液样本52份。采用实时聚合酶链反应（real-time PCR）对BKPyV进行检测与定量分析。为比较血液与唾液中BKPyV的检出情况，采用二项比例检验；为分析唾液BKPyV排出情况与移植后时长（单位：月）的关联，采用曼-惠特尼U检验（Mann-Whitney test）；为探讨肾移植受者唾液与血液病毒载量的相关性，采用斯皮尔曼相关分析（Spearman's correlation）。
结果：本研究队列的平均年龄为51.11±12.45岁，其中69名受试者为女性（占比54.8%），移植后平均时长为4.80±6.04个月。在多份唾液与血液样本中均检测到BKPyV，其病毒载量中位数分别为1108拷贝/毫升与1255拷贝/毫升。仅16/52（30.8%）的受试者血液中检出BKPyV，而59/126（46.8%）的受试者唾液中可排出该病毒（p=0.004）。唾液中检出BKPyV的受试者移植后时长更短（3.86±5.25，p=0.100）。唾液与血液中的病毒载量仅存在弱相关性（斯皮尔曼相关系数=0.193）。
结论：本研究结果提示，尽管唾液中BKPyV的排出率高于血液，但唾液排毒与血液病毒血症之间无可靠相关性，提示二者为独立的病毒复制区域。