[Clinical and laboratory features of SF3B1-mutated myeloproliferative neoplasms]

Objective: To explore the clinical and laboratory characteristics of SF3B1 gene mutations in myeloproliferative neoplasms (MPN) patients. Methods: The clinical data of 273 MPN patients who were diagnosed MPN and treated in the Second Hospital of Tianjin Medical University from November 2017 to March 2023 were retrospectively analyzed. There were 133 males and 140 females, with a median age M(Q₁,Q₃)of 56(46, 67) years. The molecular biology and cytogenetic characteristics were detected by second-generation sequencing (NGS) and R+G banding techniques, and the clinical and laboratory characteristics of patients with SF3B1 gene mutation were analyzed. Results: SF3B1 gene mutations were found in 13 patients (4.8%, 13/273).The types of SF3B1 mutations included missense (92.3%, 12/13) and nonsense mutations (7.7%, 1/13).Compared to the non-mutant cohort, patients in SF3B1 mutant cohort had older ages [68(51, 76) vs 56(45, 66)years,P=0.025], higher proportion of splenomegaly [46.2%(6/13) vs 15.8%(41/259),P=0.014]and secondary tumor [23.1%(3/13)vs 3.8%(10/260), P=0.018]with higher proportion of bone marrow blast [0.5%(0, 1.5%) vs 0(0, 0.5%),P=0.002] and lower hemoglobin[(104±36) vs (137±40) g/L,P=0.004] and hematocrit [31%(22%, 40%) vs 41%(35%, 52%),P=0.003]. All of the 10 patients in the SF3B1 mutant cohort whose ring sideroblast (RS) could be evaluated showed no RS formation. The overall survival, thrombosis-free survival and leukemia free survival of MPN patients in SF3B1 mutant cohort were 4.0 (2.0, 6.0), 2.0 (0.5, 4.5) and 4.0 (2.0, 6.0) years, respectively, while patients in the non-mutant cohort were 6.0 (3.0, 10.0), 5.0 (1.0, 8.0), 6.0 (3.0, 10.0) years, respectively, there were no statistical significance between two groups (Z=3.69, 1.66, 2.05, all P>0.05).The secondary tumor free survival of SF3B1 mutant cohort patients was 4.0 (2.0, 6.0) years, which was lower than that of non-mutant cohort patients [5.5 (3.0, 10.0) years, Z=18.18, P<0.001). Conclusions: MPN patients with SF3B1 gene mutations are older, more prone to splenomegaly and secondary tumors. They also have a higher proportion of bone marrow blast, lower hemoglobin and hematocrit, and show no RS formation.