Prevalence Of Definite Antiphospholipid Syndrome In Carriers Of The Jak2(V617f) Mutation

Introduction: Patients with Philadelphia-negative myeloproliferative neoplasms (MPNs), particularly those carrying the JAK2V617F mutation, are at increased risk of thrombosis. While an association of MPNs with autoimmune disorders has been established, the prevalence of inherited or acquired thrombophilias in JAK2V617Fpositive patients remains obscure. We therefore investigated the coincidence of the JAK2V617F mutation with additional thrombogenic risk factors.Methods: In a retrospective study, we analyzed all patients referred for thrombophilia work-up between 01/2011 and 08/2019, in whom additional JAK2(V617F) mutation analysis was performed because of thromboembolic events that were recurrent, atypically located and/or associated with abnormal blood counts.Results: Of 472 tested patients, 49 (10.4%) were JAK2(V617F)-positive. While the frequency of inherited thrombophilias (factor V Leiden and prothrombin G20210A mutation, deficiency of antithrombin, protein C, protein S) was not different between the two groups, the prevalence of definite antiphospholipid syndrome (APS), mostly associated with a moderateor high-risk antibody profile, was significantly higher in patients with (22.4%) than in those without (8.4%) JAK2(V617F) mutation (p < 0.01). All evaluable JAK2(V617F)-positive patients with APS were subsequently diagnosed with MPN. In patients with JAK2(V617F) mutation, presence of concomitant APS was associated with a significantly younger age (49 +/- 14 vs. 60 +/- 15 years) at the time of thrombophilia work-up (p < 0.05).Conclusion: We found a significant association between JAK2(V617F)-positive MPN and definite APS. The presence of concomitant APS in patients carrying the JAK2(V617F) mutation may lead to earlier manifestation of thromboembolic events and may warrant more aggressive antithrombotic treatment strategies to prevent recurrence.