A Study of Haemostatic Parameters in Patients with Philadelphia-Negative Myeloproliferative Neoplasms. Correlation with, Clinical, Laboratory, Molecular, and Treatment Characteristics

Introduction Patients with Philadelphia-negative myeloproliferative neoplasms (PN-MPN) namely polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (MF) are at a higher risk for arterial and venous thrombosis that constitute a major cause of morbidity and mortality. Global coagulation assays such as thromboelastography, may be more efficient to evaluate the patient's thrombotic risk. The aim of the present study was to examine the hemostatic profile of patients with PN-MPN and correlate it with clinical, laboratory, treatment, and molecular characteristics including mutational analysis of JAK2, MPL, CALR, and polymorphisms of poly(ADP ribose) polymerase (PARP1), since a correlation of specific mutations with PARP1 polymorphisms has been reported in the literature. Materials and methods The study included adult patients with a confirmed diagnosis of PN-MPN according to the revised 2016 WHO classification. A written informed consent was obtained from all patients. The presence of splenomegaly, vascular events, PN-MPN specific therapy, and anticoagulation treatment were recorded. All the patients were assessed with complete blood count, routine coagulation tests [PT, INR, aPTT and fibrinogen, D-Dimers analyzed with the automatic coagulation analyzer Sysmex (Siemens)], platelet function performed with PFA-100 (COL, EPI, ADP), and global hemostatic potential assessed with ROTEM® Tromboelastometry (EXTEM), recording clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), lysis index at 30 (LI30) and 60 (LI60) minutes, and α angle. Mutation profiles of JAK2, MPL and CALR were defined using peripheral blood DNA. JAK2 and MPL mutations were detected using a standard PCR and CALR mutations using an HRMA-PCR assay. The rs1136410/PARP-1 (V762A) single nucleotide polymorphism (SNP), was detected with an RFLP method using the enzyme AciΙ (New England Biolabs, USA) and the digestion products were evaluated by polyacrylamide gel electrophoresis. Statistical analysis was performed using IBM SPSS statistics, version 23.0 (IBM Corporation, North Castle, NY, USA). Results Seventy-four patients were included in the study (22 PV, 47 ET, 5 MF) with a median age of 63 years (25-87) and 68 healthy controls for the SNP/PARP1 study. At the time of sample collection, 71 (95.9%) patients were under treatment [hydroxyurea (HU), 57 (77.0%); anagrelide, 19 (25.7%); ruxolitinib, 9 (12.2%); interferon alpha, 2 (2.7%); an alkylating agent, 4 (5