A more aggressive disease phenotype and poorer clinical outcomes were associated with higher baseline basophil levels among patients with myeloproliferative neoplasms (MPNs), according to the results of a retrospective study published in the American Journal of Hematology.
In the study, researchers analyzed data from 195 patients who were diagnosed with an MPN between 2008 and 2019 at a single center. Cases of chronic myeloid leukemia, chronic eosinophilic leukemia, and chronic neutrophilic leukemia were excluded. Basophilia was defined as a relative or absolute increase in peripheral blood or bone marrow aspirate within 6 months of the patient’s first diagnostic biopsy.
Of the 195 patients, 40.5% had essential thrombocythemia (ET), 23.1% had overt fibrotic phase primary myelofibrosis (PMF), 10.8% had post-ET myelofibrosis (MF), 8.2% had pre-fibrotic PMF, 8.2% had MPN-unclassifiable (MPN-U), 7.2% had polycythemia vera (PV), and 2.1% had post-PV MF.
Basophilia were present among 22% of patients. The lowest level of basophilia was present among patients with ET and PV at 8% compared with 35% among patients with pre-PMF, F-PMF, post-ET MF, post-PV MF, or MPN-U (P <.0001). There were 9% of patients who demonstrated basophilia in the bone marrow, but not the blood.
Of the patients without basophilia at baseline, researchers found that 12% developed basophilia within a median of 19.6 months after diagnosis. Older age (P <.001), higher white blood cell count (P <.001), higher reticulin grade (P =.0007), lower hemoglobin levels (P =.01), and lower platelet counts (P <.001) were significantly associated with basophilia.