High absolute basophil count is a powerful independent predictor of inferior overall survival in patients with primary myelofibrosis

Objectives: To investigate the clinical and prognostic significance of absolute basophil count (ABC) in patients with primary myelofibrosis (PMF).

Methods: We retrospectively investigated 58 patients with PMF treated in our institution in the period from 2006 to 2017. ABC was obtained in addition to other hematological and clinical parameters. Patients were separated into high and low ABC groups using the Receiver operating characteristic curve analysis.

Results: ABC was higher in PMF patients than in healthy controls (P?P?P?=?0.035), higher lactate dehydrogenase (P?P?P?=?0.030) and massive splenomegaly (P?=?0.014). ABC was also positively correlated with absolute monocyte count (AMC) (P?P?P?=?0.009) in a multivariate Cox regression model adjusted for age, gender, Dynamic International Prognostic Scoring System (HR 2.6, P?=?0.001) and AMC (HR 8.45, P?=?0.002).

Discussion: High ABC reflects higher disease activity and stronger proliferative potential of disease. ABC and AMC independently predict survival and therefore seem to reflect different underlying pathophysiologic processes. Hence, both have a potential for improvement of current prognostic scores.

Conclusion: Basophils represent a part of malignant clone in PMF and are associated with unfavorable disease features and poor prognosis which is independent of currently established prognostic scoring system and monocytosis.