Early monitoring of the human polyomavirus BK replication and sequencing analysis in a cohort of adult kidney transplant patients treated with basiliximab
Early monitoring of the human polyomavirus BK replication and sequencing analysis in a cohort of adult kidney transplant patients treated with basiliximab
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DOI：
10.1186/1743-422x-8-407
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发表时间：
2011-08-17
期刊：
影响因子：
4.8
通讯作者：
Pietropaolo, Valeria
中科院分区：
文献类型：
--
作者：
Anzivino, Elena;Bellizzi, Anna;Pietropaolo, Valeria
背景资料：目前，更好的免疫抑制剂降低了肾移植中的急性排斥反应率，但也导致了BKV相关性肾病（BKVAN）的出现。因此，我们前瞻性地研究了接受巴利昔单抗联合基于吗替麦考酚酯的三联免疫治疗的肾移植患者队列中血浆和尿液样本中的BKV负荷，以评估移植后前3个月内BKV复制（以巴利昔单抗的非消耗作用为特征）与后3个月内BKV复制（其中维持治疗单独作用）之间的差异。我们还进行了测序分析，以评估是否一个特定的BKV亚型/亚组或转录控制区（TCR）的变种present.Methods：我们监测BK病毒尿和病毒血症的定量聚合酶链反应（Q-PCR）在12小时（Tx），1（T1），3（T2）和6（T3）个月移植后60例肾移植患者。用TCR和VP 1区特异性引物进行巢式PCR测序分析。采用卡方检验和Student t检验对数据进行统计学分析。Tx时，在4/60例尿液和16/60例血浆中检测到BKV，中位病毒载量分别为3.70 log GEq/mL和3.79 log GEq/mL，随后BKV阳性移植物（32/60）和病毒尿中位值均显著增加（5.78 log GEq/mL）和病毒血症（4.52 log GEq/mL）。相反，在T3时观察到病毒尿和病毒血症患者（17/60）显著减少，尿液和血浆中位病毒载量降低（分别为4.09 log GEq/mL和4.00 log GEq/mL）。BKV TCR序列分析总是显示原型序列的存在，具有一些单核苷酸取代和一个核苷酸插入，有趣的是，它们都代表了我们通过VP 1测序分析鉴定的特定亚型/亚组：I/B-2和IV/c-2。我们的结果证实了先前的研究表明，BKV复制可能发生在肾移植后的早期，在移植后第3个月达到最高，然后在第6个月内下降，可能是由于诱导治疗。此外，它可能成为临床上有用的特定BKV亚型或重排是否可以链接到一个特定的疾病状态，以检测他们之前BKVAN发作。
Background: Nowadays, better immunosuppressors have decreased the rates of acute rejection in kidney transplantation, but have also led to the emergence of BKV-associated nephropathy (BKVAN). Therefore, we prospectively investigated BKV load in plasma and urine samples in a cohort of kidney transplants, receiving basiliximab combined with a mycophenolate mofetil-based triple immunotherapy, to evaluate the difference between BKV replication during the first 3 months post-transplantation, characterized by the non-depleting action of basiliximab, versus the second 3 months, in which the maintenance therapy acts alone. We also performed sequencing analysis to assess whether a particular BKV subtype/subgroup or transcriptional control region (TCR) variants were present.Methods: We monitored BK viruria and viremia by quantitative polymerase chain reaction (Q-PCR) at 12 hours (Tx), 1 (T1), 3 (T2) and 6 (T3) months post-transplantation among 60 kidney transplant patients. Sequencing analysis was performed by nested-PCR with specific primers for TCR and VP1 regions. Data were statistically analyzed using chi(2) test and Student's t-test.Results: BKV was detected at Tx in 4/60 urine and in 16/60 plasma, with median viral loads of 3,70 log GEq/mL and 3,79 log GEq/mL, respectively, followed by a significant increase of both BKV-positive transplants (32/60) and median values of viruria (5,78 log GEq/mL) and viremia (4,52 log GEq/mL) at T2. Conversely, a significantly decrease of patients with viruria and viremia (17/60) was observed at T3, together with a reduction of the median urinary and plasma viral loads (4,09 log GEq/mL and 4,00 log GEq/mL, respectively). BKV TCR sequence analysis always showed the presence of archetypal sequences, with a few single-nucleotide substitutions and one nucleotide insertion that, interestingly, were all representative of the particular subtypes/subgroups we identified by VP1 sequencing analysis: I/b-2 and IV/c-2.Conclusions: Our results confirm previous studies indicating that BKV replication may occur during the early hours after kidney transplantation, reaches the highest incidence in the third post-transplantation month and then decreases within the sixth month, maybe due to induction therapy. Moreover, it might become clinically useful whether specific BKV subtypes or rearrangements could be linked to a particular disease state in order to detect them before BKVAN onset.