Badwal Sonia, Chopra G S, Varma P P, Hooda A K
Reader, Department of Pathology, AFMC, Pune.
MG (Med) HQ (Central Command) Lucknow.
Med J Armed Forces India. 2011 Apr;67(2):122-30. doi: 10.1016/S0377-1237(11)60009-9. Epub 2011 Jul 21.
BK polyoma viral nephropathy (BKVAN) has emerged as a significant cause of renal allograft loss. The literature on BK viral infection from India is scarce. The study was therefore undertaken to evaluate impact of BK polyoma viral (BKV) infection on renal allograft recipients in Indian scenario from a service renal transplantation centre.
Renal allograft recipients who underwent graft biopsy formed the part of this descriptive cross-sectional study group. The clinicopathological profile of the patients was analysed. The diagnostic modalities employed were histopathology, immunohistochemistry using antibody for Simian virus 40 large T antigen along with real time quantification of the BK viral DNA load in the urine and the serum.
One hundred forty seven renal allograft recipients were evaluated. 73.47 percent (108/147) patients presented with graft dysfunction and rest were protocol biopsies. There were 53 cases of rejection related diagnosis, 8 cases of graft pyelonephritis, 64 cases showed normal histology and rest exhibited miscellaneous causes. Nineteen percent (28/147) cases were positive for BKV DNA (viruria 26/147, 17.6% and viraemia 8/147, 5.44%. 3.4 percent (5/147) exhibited histological and immunohistochemical evidence of BKVAN. Nuclear enlargement, smudging and intranuclear inclusions along with plasma cell rich interstitial nephritis were important features observed on histopathology. Concomitant acute rejection was seen in 4/5 cases of BKVAN. All cases of BKVAN exhibited viraemia (> 2500 copies/mL), though cut-off values could not be defined statistically due to small sample size. Positive statistical correlation was observed between use of anti-thymocyte globulin (induction therapy and/or treatment of steroid resistant rejection, Pearson ×(2) value 6.9, P=0.008) and rejection episodes (Pearson ×(2) value 9.8, P = 0.007) with BKV infection.
BK polyoma nephropathy should be added to the list of differential diagnosis considered for a renal allograft dysfunction. Renal biopsy remains the gold standard for diagnosis supplemented by non-invasive molecular techniques for screening and monitoring of BKV infection.
BK多瘤病毒肾病（BKVAN）已成为肾移植失败的一个重要原因。来自印度的关于BK病毒感染的文献很少。因此，本研究旨在从一个肾脏移植服务中心评估在印度情况下BK多瘤病毒（BKV）感染对肾移植受者的影响。
接受移植肾活检的肾移植受者构成了这个描述性横断面研究组的一部分。分析了患者的临床病理特征。采用的诊断方法包括组织病理学、使用针对猴病毒40大T抗原的抗体进行免疫组织化学，以及对尿液和血清中BK病毒DNA载量进行实时定量分析。
对147例肾移植受者进行了评估。73.47%（108/147）的患者出现移植肾功能障碍，其余为方案活检。有53例与排斥反应相关的诊断，8例移植肾盂肾炎，64例组织学正常，其余表现为其他原因。19%（28/147）的病例BKV DNA呈阳性（病毒尿26/147，17.6%；病毒血症8/147，5.44%）。3.4%（5/147）表现出BKVAN组织学和免疫组织化学证据。组织病理学观察到的重要特征包括核增大、核模糊、核内包涵体以及富含浆细胞的间质性肾炎。5例BKVAN病例中有4例同时伴有急性排斥反应。所有BKVAN病例均出现病毒血症（>2500拷贝/mL），不过由于样本量小，无法进行统计学上的临界值定义。观察到使用抗胸腺细胞球蛋白（诱导治疗和/或治疗类固醇抵抗性排斥反应，Pearsonχ²值6.9，P = 0.008）以及排斥反应发作（Pearsonχ²值9.8，P = 0.007）与BKV感染之间存在正相关。
BK多瘤肾病应列入肾移植功能障碍的鉴别诊断清单。肾活检仍然是诊断的金标准，辅以非侵入性分子技术用于BKV感染的筛查和监测。
