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Abstract: SA-PO490

Predictive Value of the Combination of Peripheral Blood Lymphocyte Count and Urinary Cytology in the Diagnosis of Polyomavirus BK Nephropathy

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational


  • Masutani, Kosuke, Kyushu University, Fukuoka, Japan
  • Tsuchimoto, Akihiro, Kyushu University, Fukuoka, Japan
  • Matsukuma, Yuta, Kyushu University, Fukuoka, Japan
  • Okabe, Yasuhiro, Kyushu University Hospital, Fukuoka, Japan
  • Tsuruya, Kazuhiko, None, Fukuoka, Japan
  • Kitazono, Takanari, Department of Medicine and Clinical Science, Fukuoka, Japan

Screening of Polyomavirus BK (BKV) infection is recommended for kidney transplant (KT) patients. Graft biopsy is the gold standard for the diagnosis of BKV nephropathy (BKVN), and polymerase chain reaction for viral DNA is the most specific screening technique. However, the identification of non-invasive, and cost-effective marker is still important and can improve monitoring. Thus we investigated the predictive value of the peripheral blood lymphocyte (PBL) count and urinary cytology for the diagnosis of BKVN.


From July 2008 through May 2014, 492 adult patients received KT at Kyushu University Hospital. We investigated the PBL count and cytology results at graft biopsy in the patients with BKVN (BKVN group, n=21), acute T-cell mediated rejection (TCMR group, n=79), and no evidence of rejection (NoAR group, n=149). We performed univariate and multivariate logistic regression and receiver operating characteristics analyses to compare the test performance of PBL count alone, cytology alone, and their combination in the diagnosis of BKVN.


PBL count (mean ± SD) at graft biopsy was significantly lower in BKVN group than those in TCMR and NoAR groups (959 ± 290, 1433 ± 673, and 1531 ± 549 /μL, respectively, p<0.01). PBL count increased after the treatment of BKVN (at diagnosis, after 1, 2, and 3 months were 959 ± 290, 1123 ± 377, 1238 ± 419, and 1292 ± 491, respectively, p<0.05). On univariate logistic regression analysis, the area under the curve for prediction of BKVN was significantly higher in the combined model than those in PBL alone and cytology alone (0.930, 0.797 and 0.875, respectively, p<0.01). The improvement of predictive performance in the combined model remained significant after adjustment for the classical risk factors of BKVN (0.972, 0.844, and 0.928, respectively, p<0.01).


Decreased PBL count was found in the patients with BKVN. Although PBL count alone showed moderate accuracy, the predictive performance of the combination of PBL count and urinary cytology is significantly enhanced in the diagnosis of BKVN.