AB0825 JAK2 (V617F) MUTATION AND ASSOCIATION TO IMMUNE MEDIATED DISEASES. STUDY OF 130 PATIENTS FROM A SINGLE UNIVERSITY HOSPITAL
Authors: C. Álvarez-Reguera, L. Sanchez-Bilbao, A. Batlle-López, S. Fernández López, M. Á. González-Gay, R. Blanco
Journal: Annals of the Rheumatic Diseases (2021)

Background: 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). Objectives: 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. Methods: We studied all the patients diagnosed with a positive JAK-2 (V16F) mutation in a single University Hospital between January, 2004 and December, 2019. Results: 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 ). Conclusion: 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. References: [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 MPN 12 (9.2) Primary myelofibrosis (PMF) 8 (6.5) Non-rheumatic IMID 44 (33.8 ) Diabetes mellitus 22 (50) Asthma 10 (22.7) Psoriasis 6 (13.6) Crohn disease 2 (4.5) Autoimmune thyroiditis 2 (4.5) Rheumatic IMID 10 (7.7 ) Rheumatoid arthritis 4 (40) Polymyalgia rheumatica 3 (30) Sjögren disease 1 (10) Antiphospholipid syndrome 1 (10) Adult-onset Still’s disease 1 (10) Malignancies different of MPN 44 (33.8 ) Solid tumours // Hematologic malignancies // Skin cancer 22 (50) // 13 (29.5) // 9 (20.4) Deep vein thrombosis/Venous thromboembolism (DVT/VTE) events 35 (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. Disclosure of Interests: 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