Haematopoietic Stem Cell Transplant Outcomes in Patients with Thalassemia Major from a Tertiary Care Center in South India.

Abstract

<h3>Background</h3> Hematopoietic stem cell transplant (HSCT) is widely used as a gene replacement therapy in Thalassemia patients for decades. Survival probabilities after HSCT have increased considerably with advancements in graft versus host disease (GVHD) preventive strategies and conditioning regimens. Here we report our HSCT experience in patients with Thalassemia major, with different graft sources, in terms of transplant outcomes such as neutrophil and platelet engraftment, acute and chronic graft versus host disease (GVHD), thalassemia free survival and overall survival. <h3>Methods</h3> We analysed the data of 164 Thalassemia patients who have undergone HSCT between Jan-2012 to Jun-2019 at our centre. We evaluated the demographic and clinical characteristics of patients, graft source on the HSCT outcomes, such as engraftment, graft versus host disease, day-100 survival, thalassemia-free survival and overall survival. <h3>Results</h3> Out of 164 patients, 100 (61%) were males, the mean age was 9.47±4.41 (range, 1 -24) years. Peripheral blood stem cell (50%) and bone marrow (47%) are the respective graft sources with predominant matched sibling donor transplants (60.4%). One third of the patients received Fludarabine/Busulfan/Cyclophosphamide based conditioning regimen. Twenty-eight percent of the patients developed acute GVHD (grades I-IV) and 7.3% developed chronic GVHD. The average time to neutrophil engraftment was 14 (range, 8-24) days and platelet engraftment was 18 (range, 8-72) days. The average time to neutrophil engraftment and platelets engraftment did not significantly differ between the HLA-donor type (Figure 1). There were 26 deaths (15.9%) and 7 (4.3%) graft rejections during the follow-up. Infections are the major cause of deaths. The day 100 survival was 89%, the overall survival was 84% and the thalassemia free survival was 74.4%. <h3>Conclusion</h3> HSCT with various preparative regimens, GVHD preventive strategies, and varied graft sources is certainly a unique curative option for the Thalassemia major patients in the developing world. The survival after HSCT in Thalassemia patients are similar regardless of stem cell source, donor-HLA type (Figure 2) and GVHD (Figure 3). However, the incidence of GVHD is more with matched unrelated donors.