In vitro immune cell monitoring as a guide for long-term immunosuppression in adult liver transplant recipients

BACKGROUNDS/AIMS: We evaluated the clinical usability of immune cell monitoring in adult liver transplantation (LT) recipients. METHODS: This study was composed of two parts as using calcineurin phosphatase (CNP) activity assay and ImmuKnow assay independently as in vitro monitoring tools of immune cell function in adult LT recipients. RESULTS: There was a rough correlation between CNP activity and tacrolimus concentration in 33 patients. This association was evident in patients who were only administered tacrolimus, but disappeared after the co-administration of mycophenolate. In 118 healthy individuals, the mean proportion of helper T-cells was 37.4+/-8.1%. According to ImmuKnow assay, their immune responses were strong in 12 patients (10.2%), moderate in 92 patients (78.0%), and low in 14 patients (11.9%). In 85 patients waiting for LT, there was a rough correlation between the ImmuKnow ATP level and age. Their immune responses were strong in 0 patients (0%), moderate in 8 patients (9.4%), and low in 77 patients (90.6%). There was a difference in the ImmuKnow ATP levels between healthy individuals and patients with liver disease. In 137 LT recipients, there was no correlation between the ImmuKnow ATP levels and tacrolimus concentration. This trend did not change after grouping the patients according to co-administration with mycophenolate. Eight recipients experienced acute rejection, but none showed strong immune response. CONCLUSIONS: We think that both CNP activity assay and ImmuKnow assay are too limited to objectively determine the level of immunosuppression. Further studies should be performed to identify other methods for immune function monitoring.

Cylex ImmuKnow assay in Chinese stable liver transplant recipients / 中华肝胆外科杂志

Objective To identify the level of functional immunity as measured by the ImmuKnow assay in Chinese stable liver transplant recipients and to correlate these values with the dose and the trough levels of immunosuppressant, and with other clinical parameters of these patients. Methods Functional immune response was assessed by the ImmuKnow assay in 46 blood samples taken from 46 stable liver transplant recipients from Beijing Youan Hospital, Capital Medical University Liver Transplantation Center. Results The average ATP value in these stable liver transplant recipients was 203±114 ng/ml (range: 38.47 ATP ng/ml to 524.06 ATP ng/ml) at 22± 15 month post liver transplantation. There was no correlation either between ImmuKnow ATP values and the tacrolimus trough levels, or between ImmuKnow ATP values and the liver function (P<0. 05). Stepwise multiple regression analysis identified WBC and CD3+, CD3+ CD4+ as independent predictors of ImmuKnow assay levels when age, gender and underlying diagnosis were taken into account (P<0. 05). Five patients who were detected to have active HCV infection had lower ImmuKnow ATP values (<61 ng/ml). Conclusions The Cylex ImmuKnow assay ATP values were lower in Chinese stable liver transplant recipients compared with American patients. Further investigation is required to determine the role of the ImmuKnow assay in tailoring immunosuppressant therapy in liver transplant recipients.