ObjectivesWe evaluated the safety and outcome of allo-HSCTs in myelofibrosis (MF). MethodsA total of 27 patients with primary (n=20) or secondary (n=7) MF, aged 51 (21-63)yr, transplanted from HLA-matched related (59%) or unrelated (41%) donors were analyzed. Conditioning was reduced in 26 and myeloablative in one patient; and ATG was used in 25. Sources of stem cells were as follows: peripheral blood (21), bone marrow (4) or both (2). ResultsPrognostic factors that adversely affected overall survival (OS) in the multivariate analysis were as follows: recipient age >45yr (HR=10.55, P=0.025) and unrelated donor (HR=3.73, P=0.026). Post-transplant transfusion dependence adversely affected OS in the univariate analysis: dependence from either both RBCs and platelets (HR=33.26, P=0.001) or from either of them (HR=10.53, P=0.043). Of 16 JAK2V617F-positive patients evaluated post-transplant, it was eradicated in 69% and decreased in 25%. Acute GVHD III-IV developed in 19% and extensive chronic GVHD in 26% of patients; the relapse in four patients was treated with second allo-HSCT. Spleen decreased in all evaluated patients (n=24). Fibrotic changes improved or disappeared in 80% of evaluated patients (n=10). ConclusionsAllo-HSCT may prolong survival, provide disease regression and improve quality of life in MF, especially in patients 45yr transplanted from matched related donors. Achieving transfusion independence post-transplant indicates the favorable outcome.