Assessing Immunologic Function Through CD4 T-lymphocyte Ahenosine Triphosphate Levels by ImmuKnow Assay in Chinese Patients Following Renal Transplantation

Abstract

Objective Balancing immunosuppression to prevent rejection while minimizing infection/drug toxicity risk is a challenge in organ transplantation. Drug monitoring alone or with functional monitoring is inadequate to measure the immune response after transplantation. The Food and Drug Administration (FDA)-approved immune monitoring assay, ImmuKnow, offers an noninvasive method to assess the immune status of transplanted patients by measuring adenosine triphosphate (ATP) released from CD4 T cells. Herein, we have evaluated ATP levels reflecting the immune responses of Chinese kidney transplant recipients as a monitoring parameter to guide treatment after transplantation. Methods From October 2008 to March 2010, we recruited 259 kidney transplant patients who were divided into four groups: stable ( n = 174), postoperative infection ( n = 32), postoperative rejection ( n = 16), and high-dose corticosteroid treatment ( n = 33). The ImmuKnow assay was performed to measure CD4 T-cell ATP levels. No prisoners or organs from prisoners were used in the study. Results Receiver operating characteristics measurements indicated an ATP predictive range of 238 to 497 ng/mL to monitor immune responses after transplantation and immunosuppressive therapy. To identify patients with infection, we used a cutoff ATP value of 238 ng/mL with 100% specificity and positive predictive value and 92.9% sensitivity. To identify patients with rejection, we used a value of 497 ng/mL with 91.5% sensitivity. Compared with the 225 to 525 ng/mL ATP levels recommended by the FDA, our target values showed similar or better diagnostic accuracy. Conclusion We provide additional data to monitor immunosupressant treatment of Chinese kidney transplant patients.