Immunological long-term follow-up of neuroblastoma stage IV patients after anti-GD2 CH14.18 antibody treatment.

3029 Background: Neuroblastoma stage IV is associated with low cure rates. Treatment with the GD2 antibody ch14.18 could improve the long-term overall survival. Apart from GD2 other tumor antigens (TA) are expressed in neuroblastoma and studies implicated that T-cell responses to TA are associated with a better outcome. For the present study we analyzed the immune response in long term neuroblastoma survivors treated with anti GD2 ch14.18. Methods: Blood and serum of 17 neuroblastoma long-term survivors after GD2 therapy with > 5 years follow up (patients group) and 17 age and gender matched healthy donors (control group) were analyzed. Serum was analyzed for antibodies binding to neuroblastoma cell lines and antibodies to a nominal antigen GD2. T cells were stimulated with overlapping peptides of the tumor antigens (TA) NY-ESO-1, WT-1, Survivin, MAGE-A1 and two mimotope peptides to GD2 for 10 days and analyzed for IFN-γ secretion in flow cytometry. Results: T-cell responses to at least one TA could be fo...