The recovery of the capability of T-helper cells to be induced to express CD69 upon nonspecific stimulation occurs in both the naive (CD4⁺CD45RA⁺) and the memory (CD4⁺CD45RA⁻) population at 6 to 9 months after completion of TCD therapy.

PBMCs were stimulated with immobilized anti-CD3 or PHA (patient 1) and the density of expression of CD69 was assessed in CD4⁺cells (○) and in CD4⁺CD45RA⁺ cells (▪) and in CD4⁺CD45RA⁻ cells (■) at 24 hours of culture. The mpc of CD69 expression in histogram plots is expressed as percent of control at 1 to 3 months (time point 1) and at 6 to 9 months (time point 2) after completion of TCD therapy. Patient 1: 8-year-old girl with stage IV neuroblastoma (patient 1), high-dose chemotherapy with autologous stem cell rescue; patient 2: 5-year-old boy with stage IV Ewing sarcoma (patient 15), high-dose chemotherapy with autologous stem cell rescue; patient 3: 12-year-old girl with Ewing sarcoma (patient 10), conventional high-dose chemotherapy; patient 4: 15-year-old girl with germ-cell tumor (patient 16), conventional high-dose chemotherapy.