IGM to IGG anti-HLA class II antibody switching in cardiac transplant recipients reflects T cell responses to donor HLA-DR peptides and is associated with increased risk of cellular rejection and coronary artery disease: K Lietz, D Baran, E Burke, T Tung, J Ankersmit, D Mancini, N Edwards, N Suciu-Foca, S Itescu. Columbia University, New York, NY, 10032