Abstract
Graft versus Host Disease (GVHD) is the principal cause of morbidity and mortality in patients undergoing allogeneic stem cell transplant. T cell depletion has been recognized as a method of reducing the incidence of GVHD in allogeneic transplants. Until recently, most T cell depletion methods were non-selective in reducing lymphocytes. Rhodamine purging is one method, which selectively reduces alloreactive T cells preventing GVHD. We review here the methods of non-selective and selective T cell depletion, particularly the newer method of photodynamic purging utilizing rhodamine.