The increasing clinical importance of alloantibodies in kidney transplantation.

Historically, cellular rather than humoral immunity has gathered the most attention in kidney transplantation. As the specter of cellular acute rejection and early graft loss has faded due to the availability of highly effective immunosuppressive therapy, scientific and clinical studies now focus on improving long-term graft survival. It is increasingly appreciated that alloantibodies directed against HLA and non-HLA antigens are key factors in determining graft longevity. Significant efforts are now being made to better understand the critical impact that B cells and alloantibodies make on organ allocation and graft survival. Future therapies directed specific for the humoral alloresponse will undoubtedly lead to improved outcomes after kidney transplantation. This review will cover some of the advances in the understanding and management of the continuum of humoral immunity in renal transplantation in the pre, peri and post-transplant periods.