Modification of donor lymphocyte infusion: how to improve the outcome?

(HSCT),which has been acknowledged as a curative procedure,relapse of leukemia remains the leading cause of death following transplantation and is a disappointment to transplant physicians.Leukemic relapse occurs due to leukemia cell escape from immune-mediated killing (immune escape) by pre-transplantation conditioning and post-transplantation immune control.Immune exhaustion of donor T cells is one of the common causes of relapse,and donor lymphocyte infusions (DLIs) have the potential to reverse this immune exhaustion.Patients who are deemed eligible for intensive treatment at this point are offered either DLI or a second transplant.Contrary to the contemporary understanding,DLI results in the same response and survival obtained via a second transplant but with less toxicity (Kharfan- Dabaja et al.,2018).Starting in the mid-1990s,our group along with few others demonstrated the efficacy of DLI,which was initially confirmed by the Hadassah group in Jerusalem in the late 1980s.In the first four patients (with both acute and chronic leukemias) treated by us with DLI,the initial success rate was 100%,which encouraged us to pursue this treatment further.