One reason would be that CD4 and CD8 populations undergo major changes with age. There’s a shift towards exhausted phenotype. Immune system produces fewer and f

One reason would be that CD4 and CD8 populations undergo major changes with age. There’s a shift towards exhausted phenotype. Immune system produces fewer and fewer naive T cells in the bone marrow, thymus is less efficient in adulthood as well. I’d imagine CAR-Ts are less efficient in older adults. So getting in relapse after a decade would put a patient in a different position.