Immunotherapy With CD19ζ Gene-modified EBV-specific CTLs After Stem Cell Transplant in Children With High-risk Acute Lymphoblastic Leukaemia

All patients will be treated at the same total dose level of 2 x 10\^8/m2

The initial cohort of 5 patients (regardless of arm of study) will be treated as described. If transduced CTL infusion is safe in this initial cohort and real-time DNA PCR studies demonstrate that transduced CTL are undetectable in \> 50% of patients by 2 months post-infusion, the remaining 25 patients (in either arm of the study) will be treated as above but with an additional vaccination of CD19-zeta-transduced EBV-LCL infusion. Vaccination will consist of 3 doses of 5 x 10\^6 irradiated (70Gy) donor-derived EBV-lymphoblastoid cell line used to generate CTL and will be administered subcutaneously into the thigh (volume 0.3 ml) at day -2, week 4 and 8 post-transduced CTL infusion.