%0 Journal Article %T Immune Response following Liver Transplantation Compared to Kidney Transplantation: Usefulness of Monitoring Peripheral Blood CD4+ Adenosine Triphosphate Activity and Cytochrome P450 3A5 Genotype Assay %A Yu Nobuoka %A Shugo Mizuno %A Kouhei Nishikawa %A Kaname Nakatani %A Yuichi Muraki %A Tomomi Yamada %A Masahiro Okuda %A Tsutomu Nobori %A Yoshiki Sugimura %A Shuji Isaji %J Journal of Immunology Research %D 2013 %R 10.1155/2013/936063 %X Seventy living donor liver transplantation (LDLT) and 39 kidney transplantation (KT) patients were randomly screened by using the peripheral blood CD4+ adenosine triphosphate activity (ATP) assay (IMK assay). The patients were divided into 2 groups in each organ transplantation with low IMK ATP level (<225£¿ng/mL) or high (>225) (LT-L: , KT-L: , LT-H: , and KT-H: , resp.). The incidence of bacterial and/or viral infection was significantly higher in LT-L group than in LT-H group (74.0 versus 8.5%: ). Occurrence of total viral infection in KT-L was also significantly higher than that in KT-H (36.8 versus 10%: ). The sensitivity and specificity of the IMK assay for identifying risk of infection was 0.810 and 0.878 in LDLT patients and 0.727 and 0.607 in KT patients. The percentage of LDLT patients with cytochrome P450 3A5 (CYP3A5) or genotype (expressors) was significantly higher in LT-L group than in LT-H group (53.8 versus 20.7%: ). In both LDLT and KT patients, the IMK assay can be useful for monitoring immunological aspects of bacterial and/or viral infection. CYP3A5 expressors in LT-L group are related to postoperative infections. 1. Introduction In solid organ transplantation, including liver transplantation (LT) and kidney transplantation (KT), graft and patient survival has been greatly improved during recent two decades, mainly due to the introduction of a variety of immunosuppressive agents including calcineurin inhibitors (CIs) as well as the advances in surgical technique and perioperative management. However, CIs have a narrow therapeutic window, and too little use of immunosuppressive agent may increase the risks of acute and chronic rejection [1], whereas too much immunosuppression may cause infection, malignant disease, and other undesirable adverse effects [2, 3]. The measuring trough levels of CIs combined with laboratory data is widely accepted practice for monitoring solid organ transplants [4, 5], although neither of them is always sensitive or specific for assessing the current immunosuppressive status. The ImmuKnow (IMK) assay, which was approved by the Food and Drug Administration in 2002, can monitor CD4+ T cell function by measuring the intracellular concentration of adenosine triphosphate (ATP). This assay has been used for identifying transplant patients at risk for infection (with low IMK ATP levels) or rejection (with high IMK ATP levels) [6, 7], whereas others argue against its predictive usefulness [8, 9]. In each organ transplant recipient, the true benefit of IMK assay for monitoring of immunological aspects needs to be %U http://www.hindawi.com/journals/jir/2013/936063/