Implication of interleukin-2 receptor antibody induction therapy in standard risk renal transplant in the tacrolimus era: a meta-analysis

BACKGROUND: Interleukin-2 (IL-2) antagonist has been used as an induction therapy in many centres in calcineurin inhibitor-sparing regimens. Tacrolimus has overwhelmingly replaced cyclosporine in the maintenance immunosuppressive protocols in many transplant centres. The aim of our study and meta-analysis is to explore the effect of IL-2 induction therapy on the rate of rejection and patient and graft survival in standard-risk renal transplant patients with tacrolimus-based maintenance immunotherapy. Secondary aims included assessment of the effect of IL-2 induction therapy on creatinine change and the risk of cytomegalovirus (CMV) infection. METHODS: We conducted a systematic review in different databases to identify studies and research work that assessed the effect of IL-2 antibody induction therapy on renal transplant outcomes. Inclusion criteria for our meta-analysis were all studies that compared IL-2 induction therapy with placebo or no induction therapy in standard-risk renal transplant recipients on tacrolimus-based maintenance immunosuppressive therapy. Data collected were the name of the first author, journal title, year of publication, country where the study was conducted, number of patients in the IL-2 induction therapy arm and in the placebo arm, number of patients who had biopsy-proven rejection and graft survival in each arm. A random effects model was used for the meta-analysis. RESULTS: Of the 470 articles found in different databases, 7 were included in the meta-analysis. Forest plot analysis for rate of rejection during the follow-up period post-transplant showed no significant difference between the groups. There was no evidence of heterogenicity between included studies (I(2) = 21.8%, P = 0.27). The overall risk difference was −0.02 [95% confidence interval (CI) −0.05–0.01]. A random effects meta-analysis for patient and graft survival was performed using forest plot analysis and showed no significant effect of IL-2 receptor (IL-2R) antibody induction on patient or graft survival compared with placebo. The overall risk difference was −0.01 (95% CI −0.04–0.01) and 0.00 (95% CI −0.00–0.01), respectively. Three of the included studies showed no effect of basiliximab on creatinine change, two showed no effect on risk of CMV infection and two showed less risk of post-transplant diabetes in the basiliximab group. CONCLUSION: IL-2R antibody induction therapy has no significant effect on the rate of rejection or patient or graft survival in standard-risk renal transplant recipients on tacrolimus-based maintenance immunotherapy. More randomized controlled studies are needed.