Usefulness of Monitoring Cell-Mediated Immunity for Predicting Post-Kidney Transplantation Viral Infection

Background. Monitoring cell-mediated immunity (CMI) can be used to estimate the risk of viral infections in kidney transplant recipients. The Immuknow (IMK) assay measures CD4(+) T-cell adenosine triphosphate activity, assesses patient CMI status, and assists clinicians in determining the risk of viral infection. Methods. We retrospectively analyzed 224 IMK values in 39 kidney transplant recipients at our institution from April 2012 to January 2013. We analyzed the relationship between IMK value and viral infection during the early and late post-transplantation periods. Multiple regression analyses were performed, to determine which factors impacted the results of the IMK assay. Results. Eight patients developed viral infections, including BK virus, cytomegalovirus, herpes simplex, and shingles. Five infections occurred in the early post-transplantation period (<50 d) and 3 in the late period (>120 d). The IMK levels in patients who developed an infection in the early period were within normal limits; however, those in the late period were significantly lower than 200 ng/mL (421.0 +/- 062.6 for early vs 153.7 +/- 72.7 for late; P = .02). Our multiple regression analyses indicated that peripheral white blood cell and neutrophil counts affected IMK values (P = .03 and P = .02, respectively). Conclusions. The IMK assay is a useful test for identifying patients at risk for post-transplantation viral infections in the late transplant period.