Increased Mast Cell Numbers in Bone Marrow of Patients with Myeloproliferative Neoplasms (MPN) and Pruritus
Maud Hermans1, Peter Westerweel2, Thierry van den Bosch3, Willem Dik4, King Lam3, Sanne Van Den Meerendonk4, Francien Nederveen5, Vincent van der Velden4, Peter te Boekhorst61Department of Internal Medicine, section Allergy & Clinical Immunology, Erasmus MC, Rotterdam, The Netherlands2Department of Internal Medicine, section Hematology, Albert Schweitzer hospital, Dordrecht, The Netherlands
3Department of Pathology, Erasmus MC, Rotterdam, The Netherlands
4Laboratory of Medical Immunology, Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
5PAL Dordrecht, The Netherlands
6Department of Hematology, Erasmus University Medical Center, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
Pruritus might be a debilitating symptom in myeloproliferative neoplasms (MPN). Since mast cells (MC) play a pivotal role, we hypothesized that bone marrow (BM) MC contribute to the cause of pruritus. In this exploratory study, untreated MPN patients were included. BM aspirate/biopsy/blood and MPN-SAF questionnaires were obtained. Thirty-two patients were included (Essential Thrombocythemia n=19, Polycythemia Vera n=7 and Primary Myelofibrosis n=6). Eleven had clinically significant pruritus (35%). The absolute MC count and proportion/total nucleated BM-cells were significantly higher in patients with pruritus compared to those without (mean 25.5 vs. 58.1 MC/mm2, p 0.032, and 0.59 vs 1.66%, p 0.041, respectively). The MC immunophenotype and serum levels of tryptase, IL-6, TNF-α and sCD117 were not correlated.
The absolute and relative MC numbers are increased MPN patients with pruritus. Whether MC play a athophysiological role in causing pruritus, or are bystanders remains to be determined
Keywords: Myeloproliferative Neoplasms, Mast cells, Pruritus
Manuscript Language: English
Copyright © 2026 Turkish Journal of Hematology