INDUCTION IMMUNOSUPPRESSION

K. Samy¹, M. Rees², S. Selman², D. Malhotra¹, D. Kaw², S. Ratnam², J. Shapiro^2
1, University of Toledo, Toledo/OH/UNITED STATES OF AMERICA, ², University of Toledo Medical Center, Toledo/OH/UNITED STATES OF AMERICA

Body: Background: Alemtuzumab (Campath 1-H) is an antibody against CD52 that depletes T cells, B cells and macrophages. In our experience, Campath induction allowed for a steroid-free maintenance immunosuppression regimen. Initially, tacrolimus (Prograf) monotherapy was used for post-transplant immunosuppression; mycophenolic acid (Myfortic) was later added to the regimen. Here we evaluate the value of adding Myfortic to Prograf maintenance immunosuppresion following Campath induction with a two year follow-up.
Methods: Data was collected retrospectively from patients transplanted between 3/14/2006 to 12/31/2007. Exclusion criteria limited data to two transplant surgeons and the two described drug regimens following Campath induction, resulting in a study population of 143 patients. The first group was given Prograf (P) alone (47 patients) following transplantation, with the latter group receiving Prograf and Myfortic (P/M) (96 patients). Prograf target level was 8-12 ng/ml for both groups and Myfortic target dose was 720 mg PO bid adjusted for diarrhea and leukopenia. All patients were treated with Valcyte and Bactrim prophylaxis for 6-12 months. Data collected included demographics, graft/patient survival, biopsy proven rejection episodes, and creatinine levels. Rejections were assessed for Banff score and the presence of a humoral component. Data was analyzed using SAS statistical software.

Results: Review of the study populations showed no significance differences between the two immunosuppression groups for demographic details, death censored graft survival, patient survival, rejection rate, yearly creatinine level, severity of rejection (Banff score) or humoral rejection. Death censored graft survival rates after one year were 97.8% (P) and 89.4% (P/M). Two year death censored graft survival was 88.9% (P) and 85.6% (P/M). One year patient survival was 93.6% (P) vs 95.8% (P/M) and two year patient survival was 93.6% (P) vs 90.6% (P/M). Creatinine level at one year was 1.7+/-1.2 mg/dL (P) and 1.5+/-0.6 mg/dL (P/M) and at two years was 1.7+/-1.3 mg/dL (P) and 1.5+/-0.4 mg/dL (P/M). One year overall biopsy-proven rejection rates were 21.3% (P) vs 15.6% (P/M) and two year overall biopsy-proven rejection rates were 25.5% (P) vs 19.8% (P/M). Though not achieving statistical significance, our analysis demonstrated a trend toward differences in response to therapy based on ethnicity. At two years, rejection rates were 22.6% for Caucasians in both study groups, whereas in African-Americans, rejection rates were 45.5% (P) and 13% (P/M) (p=0.0789). While observing a 45% rejection rate in African-Americans treated with Prograf in the absence of Myfortic, this increased rejection rate did not correspond to worsening two year graft survival (90.9%).
Conclusion: There have been numerous approaches to immunosuppression after Campath induction. This study performed at a single institution with two surgeons compared the Pittsbugh (P) and Northwestern (P/M) approaches. In this retrospective study, graft survival, patient survival and rejection rates were not statistically different between Campath induction followed by Prograf alone or in combination with Myfortic in the absence of steroids. Like the Miami experience, our data suggests caution with Campath induction in African Americans, though increased rejection rates were only seen in the absence of Myfortic and did not impact two year graft survival.

Disclosure: All authors have declared no conflicts of interest.