The Role of Alemtuzumab in Solid Organ Transplantation
National registry data indicate a trend towards increasing use of lymphocyte-depleting antibody induction therapy into immunosuppressive regimens for solid organ transplantation. Depletional induction has been shown to reduce the risk of early acute rejection, but to increase the risk of immune incompetence. As such, it has recently been paired with reduced maintenance immunosuppression in an effort to curb excessive immunosuppression without sacrificing low rejection rates. Whether this strategy benefits patients long term remains to be seen. Alemtuzumab is a humanized CD52-specific monoclonal antibody that has been used in the setting of maintenance immunosuppression minimization. Although not FDA approved for use in organ transplantation, it is now used off-label as an induction agent in approximately 10% of transplant recipients in the USA. In general, alemtuzumab is well tolerated and substantially reduces the risk of acute rejection in the first 6 months post-transplant in nonsensitized recipients. There is little evidence to support the notion that it uniquely promotes tolerance, and growing evidence that it is ineffective in preventing antibody-mediated rejection in the setting of allosensitization. Alemtuzumab-treated patients clearly remain dependent on maintenance immunosuppression. Long-term outcome data will be required to determine the magnitude and type of maintenance therapy that makes best use of alemtuzumab's depletional effects. © 2012 Blackwell Publishing Ltd.