Acute Myeloblastic Leukemia and Myelodysplastic Syndrome: Azacitidine for Prophylactic and Preventive Purposes after Allogeneic Hematopoietic Stem Cell Transplantation

Aim. To evaluate the effectiveness of preventive and prophylactic post-transplantation therapy using azacitidine (5-AZA) in patients at high risk of post-transplantation relapse. Methods. 136 patients were included in the study performed by the pairwise comparison: 68 of them received 5-AZA after allo-HSCT and 68 patients were included in the historical control group. 5-AZA was prescribed for prophylactic or preventive purposes. The results were assessed according to the OS, RR, EFS, DUM, and relapse-free and GVHR-free survival. Results. 1-year OS was 76 % in the 5-AZA group (95% CI 60–84 %) and 44 % in the reference group (95% CI 33–55 %) (p = 0.001); 2-year OS was 63 % (95% CI 39–67 %) and 37 % (95% CI 26–48 %) (p = 0.007), respectively. The relapse rate (RR) in the 5-AZA group was 34 % (95% CI 22–46 %) during 1 year and 51 % (95% CI 38–64 %) in the reference group (p = 0.02). 1- and 2-year disease unrelated mortality (DUM) was similar: 5 % in the 5-AZA group (95% CI 0.1–14.0 %) and 25 % (95% CI 13–37 %) in the reference group (p = 0.005). 1-year EFS was 76 % in the 5-AZA group (95% CI 61–85 %) and 44 % in the reference group (95% CI 33–55 %) (p = 0.001); 2-year EFS was 63 % (95% CI 39–67 %) and 37 % (95% CI 26–48 %) (p = 0.01), respectively. 1-year relapse-free and GVHR-free survival was 55 % in the 5-AZA group (95% CI 41–69 %) and 28 % in the reference group (95% CI 17–39 %) (p = 0.001); 2-year relapse-free and GVHR-free survival was 47 % (95% CI 32–62 %) and 27 % (95% CI 17–37 %) (p = 0.002), respectively. Conclusion. The use of 5-AZA for prophylactic and preventive purposes after allo-HSCT does not increase the risk of GVHR and DUM, does not suppress the GVL effect and can be used in combination with the donor lymphocyte infusion (DLI). The therapy with 5-AZA is safe during the early period after allo-HSCT. The drug does not suppress the GVL effect and can be used in high risk patients to prevent early post-transplantation relapse. The use of 5-AZA in combination with DLI does not increase the incidence of severe GVHR

Imprinting superconducting vortex footsteps in a magnetic layer

Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconducting film (Nb), into a soft magnetic layer of permalloy (Py). In full analogy with the magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py board. The mutual interaction between superconducting vortices and ferromagnetic domains has been investigated by the magneto-optical imaging technique. For thick Py layers, the stripe magnetic domain pattern guides both the smooth magnetic flux penetration as well as the abrupt vortex avalanches in the Nb film. It is however in thin Py layers without stripe domains where superconducting vortices leave the clearest imprints of locally polarized magnetic moment along their paths. In all cases, we observe that the flux is delayed at the border of the magnetic layer. Our findings open the quest for optimizing magnetic recording of superconducting vortex trajectories