An update on graft-versus-host and graft-versus-leukemia reactions: a summary of the sixth International Symposium held in Schloss Ellmau, Germany, January 22-24, 2004.

The Sixth International Symposium on Graft-versus-Host and Graft-versus Leukemia Reactions was held in Schloss Ellmau (near Garmisch-Partenkirchen, Germany) between January 21 and 24, 2004. A total of 110 invited participants (scientists and clinicians working in the area of allogeneic stem cell transplantation) discussed current topics. Major topics of the 2004 meeting were: clinical results of donor lymphocyte infusions, basic biology, immunogenetics, function and clinical relevance of natural killer cells, haplo-identical stem cell transplantation, immune monitoring and immune modulation. Further highlights were: adoptive immunotherapy, vaccination and antibody-mediated strategies. As can be seen in the summaries of the individual presentations, important advances have occurred in our understanding of GVH and GVL reactions. Each session was followed by an animated discussion, which resulted in new ideas, insights and projects both for basic research and clinical transplantation. This year's symposium ('From Marrow Transplantation to Cell Therapy') was jointly organized by the Ludwigs-Maximilians-University of Munich (Sonderforschungsbereich 455), GSF (National Research Center for Environment and Health) and the EBMT Immunobiology Working Party. The organizers and authors of the conference proceedings would like to extend their gratitude to all participants for sharing their ideas, slides and manuscripts and making this event possible.