Single Dose of Alemtuzumab Induction With Steroid-Free Maintenance Immunosuppression in Pancreas Transplantation

Alemtuzumab is a humanized anti-CD52 monoclonal antibody that is aimed for treatment of chronic lymphocytic leukemia and has now been increasingly used in organ transplantation (1). CD52 is a glycoprotein expressed on approximately 95% of peripheral blood lymphocytes, natural killer cells, monocytes, macrophages, and thymocytes; therefore, almost all mononuclear cells are affected (2). There does not seem to be any effect on plasma cells and similar to other induction agents, alemtuzumab seems to spare memory type cells (3). After binding to its target, alemtuzumab causes cell death through several mechanisms including complement-mediated cytolysis, antibody-mediated cytotoxicity, and apoptosis. Although the plasma elimination half-life of alemtuzumab is approximately 12 days, its clinical effects are far more persistent (1, 4). Lymphocyte depletion of more than 99% can be seen after a single dose with varying rates of cellular recovery depending on the subpopulation of interest (5). The first reports of renal transplantation recipients treated with alemtuzumab induction with low dose cyclosporine monotherapy were described by Calne et al. (6, 7). Subsequently, alemtuzumab has increased in popularity as an induction immunosuppression for organ transplantation (1, 8–11). Alemtuzumab induction has demonstrated its ability of low-dose maintenance immunosuppression without steroid with acceptable risk of early rejection or calcineurin inhibitor and steroid free (12, 13). The majority of the clinical experience with alemtuzumab has been primarily with renal transplantation, and the experience of alemtuzumab induction for pancreas transplantation is still limited. In this report, we describe our experience with a single dose of 30 mg alemtuzumab induction with steroid-free maintenance immunosuppression in pancreas transplantation.