Can Immune Cell Function Assay Identify Patients at Risk of Infection or Rejection? A Meta-Analysis

Background The Cylex ImmuKnow cell function assay (CICFA) is being considered as a possible tool for identification of infection and rejection in transplant recipients. However, the predictive capability of CICFA is still unclear. Methods Herein, we performed a meta-analysis to assess the efficacy of CICFA in identifying risks of infection and rejection posttransplantation. After a careful review of eligible studies, sensitivity, specificity, and other measures of the accuracy of CICFA were pooled. Summary receiver operating characteristic curves were used to represent the overall test performance. Results Nine studies met the inclusion criteria. The pooled estimates for CICFA in identification of infection risk were poor, with a sensitivity of 0.58 (95% confidence interval [CI]: 0.52-0.64), a specificity of 0.69 (95% CI: 0.66-0.70), a positive likelihood ratio of 2.37 (95% CI: 1.90-2.94), a negative likelihood ratio of 0.39 (95% CI: 0.16-0.70), and a diagnostic odds ratio of 7.41 (95% CI: 3.36-16.34). The pooled estimates for CICFA in identifying risk of rejection were also fairly poor with a sensitivity of 0.43 (95% CI: 0.34-0.52), a specificity of 0.75 (95% CI: 0.72-0.78), a positive likelihood ratio of 1.30 (95% CI: 0.74-2.28), a negative likelihood ratio of 0.96 (95% CI: 0.85-1.07), and a diagnostic odds ratio of 1.19 (95% CI: 0.65-2.20). Conclusion The current evidence suggests that CICFA is not able to identify individuals at risk of infection or rejection. Additional studies are still needed to clarify the usefulness of this test for identifying risks of infection and rejection in transplant recipients.