LAUSR

Janus Kinases (JAK) are tirosin-kinases that can promote cytokine production in immune and hematopoietic cells. The JAK-2 (V617F) mutation is the most frequently detected mutation in myeloproliferative neoplasms (MPN) which include essential thrombocythemia (ET), polycythemia vera (PV), primary myelofibrosis (PMF) and undifferenciated MPN. JAK-2 (V617F) mutation displays a pro-inflammatory phenotype that may be associated to a higher risk of immune mediated diseases (IMID), thromboembolic complications or other cancers (1-3).To evaluate the presence of a) IMID (rheumatic and non-rheumatic), b) cancer and, c) Deep vein thrombosis/ Venous thromboembolism (DVT/VTE) events in a cohort of patients with a positive JAK-2 (V617F) mutation.We studied all the patients diagnosed with a positive JAK-2 (V16F) mutation in a single University Hospital between January, 2004 and December, 2019.The study included 130 patients (73 men/57 women; mean age, 70.1±14.5 years). They were diagnosed of ET (n=64, 49.2%), PV 46 (35.4%), undifferentiated MPN (n=12, 9.2%) and PMF (n=8, 6.1%). Of these patients, 54 (41.5 %) (44 non rheumatic and 10 rheumatic) were diagnosed with at least one IMID, 46 (35.4%) with other cancer different of MPN and 36 (27.7%) with DVT/VTE events. (Table 1/Figure 1).Due to its prevalence and potential complications, IMID should be taken into consideration when a patient is diagnosed with a positive JAK-2 (V617F) mutation.[1]Perner F, et al. Cells. 2019;8:854.[2]Xu Q, et al. Clin Rheumatol. 2020 Jul 16.[3]Hasselbalch HC, et al. 2020; 23;17(1):248.Table 1.Associated diseases in 130 patients with JAK2 (V617F) mutation. Data are n (%)Myeloproliferative neoplasms (MPN)130 (100) Essential thrombocythemia (ET)64 (49.2) Polycythemia vera (PV)46 (35.4) Undifferentiated MPN12 (9.2) Primary myelofibrosis (PMF)8 (6.5)Non-rheumatic IMID44 (33.8) Diabetes mellitus22 (50) Asthma10 (22.7) Psoriasis6 (13.6) Crohn disease2 (4.5) Autoimmune thyroiditis2 (4.5)Rheumatic IMID10 (7.7) Rheumatoid arthritis4 (40) Polymyalgia rheumatica3 (30) Sjögren disease1 (10) Antiphospholipid syndrome1 (10) Adult-onset Still’s disease1 (10)Malignancies different of MPN44 (33.8) Solid tumours // Hematologic malignancies // Skin cancer22 (50) // 13 (29.5) // 9 (20.4)Deep vein thrombosis/Venous thromboembolism (DVT/VTE) events35 (26.9)Figure 1.Associated diseases accordingly to the subtype of Myeloproliferative neoplasm. Data are n.ABBREVIATIONS: DVT/VTE: Deep vein thrombosis/ Venous thromboembolism. ET: Essential Thrombocythemia, IMID: Immune Mediated Diseases, PV: Polycythemia Vera; MPN: Myeloproliferative Neoplasms; PMF: Primary myelofibrosis; UMPN: Undifferenciated myeloproliferative neoplasms.Carmen Álvarez-Reguera: None declared, Lara Sanchez-Bilbao: None declared, Ana Batlle-López: None declared, Sara Fernández López: None declared, Miguel Á. González-Gay Speakers bureau: Abbvie, Pfizer, Roche, Sanofi and MSD., Grant/research support from: Abbvie, MSD, Janssen and Roche, Ricardo Blanco Speakers bureau: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen, Lilly and MSD., Grant/research support from: Abbvie, MSD and Roche