Prevalence of Paroxysmal Nocturnal Hemoglobinuria Clones in Myeloproliferative Neoplasm Patients: A Cross-Sectional Study.

The myeloproliferative neoplasms (MPN) are clonal diseases that confer an increased risk of thrombohemorrhagic complications. Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disease associated with an increased thrombotic risk. Small PNH clones are prevalent in aplastic anemia and myelodysplastic syndrome patients, but their prevalence in MPN patients is unknown.Consecutive patients with MPN followed up at a single center were recruited. PNH clones were analyzed in erythrocytes and white blood cells by flow cytometry.PNH clones were detected in 2% of patients and were more common in JAK2 V617F positive patients. We could not detect any differences in clinical manifestations or complications in patients either with or without PNH clones because of the small patient numbers.The prevalence of PNH clones in MPN is similar to that described in myelodysplastic syndromes. Whether PNH clones influence MPN phenotype and complications should be studied prospectively in larger patient cohorts and over long-term follow-up.