Low‐dose methotrexate may preserve a stronger antileukemic effect than that of cyclosporine after modified donor lymphocyte infusion in unmanipulated haploidentical HSCT

To compare the impacts of low‐dose methotrexate ( MTX ) with cyclosporine ( CSA ) on graft‐versus‐host disease ( GVHD ) and graft‐versus‐leukemia ( GVL ) effect after haploidentical modified donor lymphocyte infusion ( DLI ). Fifty‐five consecutive patients who had relapsed acute leukemia after haploidentical hematopoietic stem cell transplantation ( HSCT ) and received modified DLI were retrospectively studied. Forty‐one patients received CSA and 14 received low‐dose MTX after DLI to prevent DLI ‐associated GVHD . The incidence of acute GVHD and grade 2–4 acute GVHD in MTX group showed a trend toward being higher than in CSA group (61.0% vs. 37.3%, p = 0.198 and 61.0% vs. 35.5%, p = 0.155). However, no significant difference in the incidence of grade 3–4 acute GVHD between two groups (p = 0.982) was observed. Moreover, compared with CSA , patients treated with MTX had lower re‐relapse rate (38.1% vs. 80.8%, p = 0.029), better disease‐free survival ( DFS ) (51.9% vs. 15.6%, p = 0.06), and higher absolute lymphocyte counts at 30, 45, 60, and 90 d after modified DLI (p < 0.05). This study suggested that after haploidentical modified DLI , low‐dose MTX is at least as effective as CSA in the prevention of DLI ‐associated GVHD and probably allowed stronger GVL effect than CSA . This phenomenon was probably due to a direct antitumor effect and a better reconstitution of lymphocytes after modified DLI induced by low‐dose MTX .