Reduced progression of cardiac allograft vasculopathy with routine use of induction therapy with basiliximab

Novel Immunosuppression in Solid Organ Transplantation

Solid organ transplantation and survival has improved tremendously in the last few decades, much of the success has been attributed to the advancements in immunosuppression. While steroids are being replaced and much of the immunosuppressive strategies focus on steroid free regimens, novel agents have introduced in the induction, maintenance, and treatment of acute rejection phase. MTOR inhibitors have helped with the renal sparing side effect from the calcineurin inhibitors, newer agents such as rituximab have decreased the incidence of donor-specific antibodies which led to decreased incidence of acute rejection reactions. In this chapter we discuss the newer therapies directed specifically for solid organ transplantation.

Outcomes of Induction Therapy with Rabbit Anti-Thymocyte Globulin in Heart Transplant Recipients: A Single Center Retrospective Cohort Study

Background

Induction immunosuppression is used in transplantation to prevent early acute rejection. The survival benefit of rabbit anti-thymocyte globulin (rATG) induction has not been established yet. We sought to determine the role of rATG in preventing rejection and improving overall survival.

Material/Methods

A retrospective cohort study was conducted from 2005 to 2009 and data of consecutive 268 heart transplant recipients were reviewed.

Results

The data of 144 patients who received induction with rATG were compared to 124 patients who did not. Although overall survival was not different between the 2 groups (P=0.12), there was a significant difference in restricted mean survival time (RMST) at 5 years (RMST=4.8 months; 95% CI: 1.0–8.6, P=0.01) and 10 years (RMST=10.4 months; 95% CI: 1.6–19.3, P=0.02) in favor of the non-induced patients. No difference was observed between induced and non-induced patients who developed de novo donor specific antibodies. There was a significant difference in median days to first rejection in favor of the induced group (P<0.001).

Conclusions

Induction with rATG adds no survival benefit in heart transplant recipients. Patients who did not receive induction therapy had higher life expectancy at 5 years and 10 years. Although there was significant delay in the first rejection episode in favor of the rATG induced group, no difference was observed in donor specific antibodies. This study indicates a need for separate analysis of peri-transplantation co-morbidities and mainly the incidence of acute kidney injury, which could affect long-term survival.

Desensitization Strategies Pre- and Post-Cardiac Transplantation

OPINION STATEMENT

Panel reactive antibody (PRA) testing has become standard in the evaluation of patients prior to cardiac transplant. Sensitizing events such as blood transfusions, which result in the accumulation of pre-transplant antibodies, should be avoided as clinically feasible. Desensitization therapy might be considered in sensitized patients with cPRA > 50 % although distinct cutoff PRA values for initiating therapy pre-transplant are patient and transplant program dependent. Post-cardiac transplant, quantitative antibodies should also be periodically analyzed, at intervals individualized to the patient. Donor-specific antibodies (DSA) after cardiac transplantation have been shown to be associated with worsened survival. It appears that complement fixing DSA confer the greatest risk for antibody-mediated rejection post-transplant. Desensitization strategies aim to reduce the number of clinically important antibodies prior to and after transplant, both by removal of antibodies and cessation of further production. Current desensitization regimens include pharmacologic, procedural, and surgical modalities, and must be individualized to the patient. Currently, most cardiac transplant programs tailor the post-transplant immunosuppressive regimen based on clinical factors and immunologic assays and may include the use of cytolytic induction and/or intravenous immune gammaglobulin in higher risk patients.