Neutrophil-lymphocyte and platelet-lymphocyte ratios as predictors of atherosclerotic thrombotic risk in patients with myelofibrosis

Abstract Myelofibrosis (MF) isa chronic myeloproliferative neoplasm associated with risk of atherosclerotic cardiovascular disease (ASCVD), including myocardial infarction (MI) and stroke. It is reported that MF has chronic inflammation characterized by monocytosis. The monocytosis is responsible for accelerate atherosclerosis with arterial plaque formation. The atherosclerotic plaque may be reflected in peripheral blood by acute-phase reactans such as C-reactive protein (CRP). However, it is debated whether CRP has a causal role in the development of cardiovascular disease in MF. As it is reported that acute-phase reactants such as neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are predictors of thrombotic risk in patients with MI, we measured NLR and PLR in association with the absolute neutrophil (ANC), lymphocyte (ALC), and platelet count in 20 JAK2V617F-negative lower-risk IPSS (low-intermediate-1) patients with diagnosis of MF according to ICC/WHO criteria and thrombosis. As it is reported that acute-phase reactans are present in atherosclerotic plaques, we measured internal carotid artery intima-media thickness (ICA-IMC). Nobody had infiammatory disease, chronic kidney disease or cardiovascular risk factors. The mean age was 58 years (35-60 years). 12/20 and 8/20 were low- and intermediate-1-risk IPSS, respectively. 6/20 low-risk had MI and 5/20 intermediate-risk had stroke. ANC, ALC and platelets were measured by automated hematology counter (Mindray BC-6800). ICA-IMC was measured by ultrasonography. Analysis were performer separately for with thrombosis and without thrombosis patients. ANC was higher in patients with thrombosis vs patients without thrombosis (>9.3x109/L vs >8.3x109/L) as well as ALC (>3.0x109/L vs <1.5x109/L). Platelets were higher (650x109/L) in patients with thrombosis in comparison to patients without thrombosis (350x109/L). NLR values were higher in patients with thrombosis vs patients without thrombosis (>4.5 vs >3.0) as well as PLR values (350 vs 200). An association there was between high NLR/PLR and size of carotid plaque in patients with thrombosis vs patients without thrombosis (>1.5 mm vs <1.5 mm). We speculate that high NLR/PLR ratios in MF with overt ASCVD underlie a higher degree of systemic and arterial inflammation which may contribute to atherosclerotic plaque and promote the occurrence of ischemic events in more vulnerable MF patients.