Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio as novel prognostic biomarkers in BCR-ABL negative myeloproliferative neoplasms.

Higher neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been associated with increased risk of thrombosis, cardiovascular mortality, but their role in myeloproliferative neoplasms (MPN) remains unclear. We analyzed NLR and PLR as prognostic markers for thrombosis and overall survival (OS) in the study that included 461 consecutive MPN patients who were diagnosed from 2018 to 2022 at University center. Twenty age-matched patients without hematological disorder were used as controls. NLR and PLR were significantly increased in whole MPN group compared to controls. NLR was highest in PV > PMF > ET (p < 0.001) while PLR was highest in ET > PMF > PV (p < 0.001). Thrombosis occurrence during follow-up correlated with NLR, NLR ≥ 4.5, presence of ≥ 2 CV factors and previous thrombosis. Arterial thrombosis was associated with previous thrombosis, NLR and NLR ≥ 4.5. Similarly in venous thrombosis previous thrombosis was risk factor, together with NLR, NLR ≥ 4.5, PLR, but also secondary malignancy and female gender. In multivariate Cox model, most important factors for thrombosis development during follow-up were previous thrombosis, NLR ≥ 4.5 and PLR ≥ 500; for arterial thrombosis, NLR ≥ 4.5 and previous thrombosis; for venous thrombosis PLR ≥ 500 and previous thrombosis. Patients with pre-PMF had significantly higher NLR than ET patients. In multivariate Cox regression model, most important factors associated with survival were NLR ≥ 4.5 and PLR ≥ 500. This study highlights strong prognostic correlation of NLR ≥ 4.5 and PLR ≥ 500 with development of thrombosis and OS in MPN. Besides previous thrombosis, most important factor associated with development of arterial thrombosis is NLR ≥ 4.5 and for venous PLR ≥ 500. Our results revealed that NLR ≥ 4.5 could be used as additional marker to distinguish ET from prePMF.