Wong A S Y, Cheng V C C, Yuen K-Y, Kwong Y-L, Leung A Y H
Department of Medicine, University of Hong Kong, Hongkong.
Bone Marrow Transplant. 2009 Jan;43(1):43-7. doi: 10.1038/bmt.2008.266. Epub 2008 Oct 6.
The polyoma BK virus (BKV) remains latent after primary infection and may reactivate during immunosuppression. The uroepithelium is the main latency site defined. This study addressed whether the gastrointestinal tract might be another latency site. To test this hypothesis, we prospectively quantified fecal BKV by quantitative PCR reaction in 40 patients undergoing hematopoietic SCT (HSCT). Urinary BKV was similarly quantified. Fecal BKV excretion was positive in 16/40 patients, of whom 10 were transient (<3 consecutively positive samples), six were persistent (> or =3 consecutively positive samples) and three were persistent with peaking (> or =10(3)-fold increase in viral load over baseline, reaching 5.11 x 10(6), 4.68 x 10(7) and 2.75 x 10(8) copies/sample at 14, 14 and 21 days post-HSCT, respectively). Urinary BKV excretion was positive in 25/40 patients. Fecal BKV excretion was significantly correlated with that of the urine (P=0.036) and was significantly associated with allogeneic HSCT (P=0.037) and persistent and peaking of urinary BKV excretion (P<0.001). Binary logistic regression showed that BKV viruria was the only significant risk factor for fecal BKV excretion (P=0.021). Fecal BKV excretion occurred in 40% patients undergoing HSCT, implicating the gastrointestinal tract as a BKV latency site.
多瘤BK病毒（BKV）在初次感染后会保持潜伏状态，并可能在免疫抑制期间重新激活。尿道上皮是已确定的主要潜伏部位。本研究探讨胃肠道是否可能是另一个潜伏部位。为了验证这一假设，我们通过定量PCR反应对40例接受造血干细胞移植（HSCT）的患者的粪便BKV进行了前瞻性定量分析。对尿液中的BKV也进行了类似的定量分析。40例患者中有16例粪便BKV排泄呈阳性，其中10例为短暂性阳性（连续阳性样本<3个），6例为持续性阳性（连续阳性样本≥3个），3例为持续性且病毒载量峰值升高（相对于基线病毒载量增加≥10³倍，在HSCT后第14天、第14天和第21天分别达到5.11×10⁶、4.68×10⁷和2.75×10⁸拷贝/样本）。40例患者中有25例尿液BKV排泄呈阳性。粪便BKV排泄与尿液BKV排泄显著相关（P = 0.036），与异基因HSCT显著相关（P = 0.037），与尿液BKV排泄的持续性和峰值显著相关（P<0.001）。二元逻辑回归显示，BKV病毒尿是粪便BKV排泄的唯一显著危险因素（P = 0.021）。40%接受HSCT的患者出现粪便BKV排泄，这表明胃肠道是BKV的一个潜伏部位。
