Monitoring cell-mediated immunity during immunosuppression reduction in heart transplant recipients with severe systemic infections

Abstract

Background: Treatment for severe systemic infections in heart transplantation is reduction in immunosuppression while treating the infection. An assay that measures adenosine triphosphate production in activated lymphocytes (ImmuKnow^® ) objectively monitors cellular immunity of transplant recipients. In this study, we used ImmuKnow^® to adjust immunosuppression in heart transplant recipients with severe systemic infections.

Methods: Heart transplant recipients were followed with ImmuKnow^® at the time of biopsy and diagnosis of systemic infection. Patients who developed an infection were monitored by ImmuKnow^® assay with adjustments in immunosuppression based upon the results of the assay. Maintenance immunosuppression was reinstituted when the ImmuKnow^® increased to >225 ng/mL of ATP.

Results: Two or more ImmuKnow^® assays were performed in 80 patients. Thirteen patients developed severe systemic infections. ImmuKnow^® mean value at the time of diagnosis of infection was 109 ± 49.2 ng/mL. Reduction in immunosuppression and treatment of infection resulted in normalization of ImmuKnow^® level, resolution of infection, and no episodes of rebound rejection.

Conclusion: Heart transplant recipients with severe systemic infections presented with a decreased ImmuKnow^® , suggesting over immunosuppression. ImmuKnow^® can be used as an objective measurement in withdrawing immunosuppression in heart transplant recipients with severe systemic infections.

Keywords: ImmuKnow; WBC count; heart transplantation; immunosuppression; severe systemic infection.