Limitations of fibrosis grade as diagnostic criteria for post polycythemia vera and essential thrombocytosis myelofibrosis

作者：Gowin K; Verstovsek S; Daver N; Pemmaraju N; Valdez R; Kosiorek H; Dueck A; Mesa R^*

来源：Leukemia Research, 2015, 39(7): 684-688.

DOI：10.1016/j.leukres.2015.04.004

• Myeloproliferative
• Myelofibrosis
• Primary
• Polycythemia
• Essential thrombocytosis

Background: The clinical phenotype of patients with myeloproliferative neoplasms (MPNs) including primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocytosis (ET) whom manifest WHO grade 1 marrow fibrosis is poorly defined. Current IWG-MRT criteria require 2+ marrow fibrosis for diagnosis of post PV/ET myelofibrosis (MF). In contrast, the 2008 WHO definition of PMF does not require a minimum fibrosis threshold.
Methods: We retrospectively analyzed the clinical characteristics of 91 MPN patients with 1+ marrow fibrosis. We compared the clinical phenotype of sub threshold fibrosis PV/ET with that manifested by PMF. We applied the IWG-MRT criteria for post-PV/ET MF with the fibrosis component omitted and evaluated for percentage of criteria fulfillment.
Results: When IWG-MRT criteria were applied to the PV/ET group, 38158 (66%) of patients fulfilled criteria for diagnosis of post-PV/ET myelofibrosis except for the 2+ fibrosis requirement. Comparison of sub threshold fibrotic PV/ET clinical phenotype to PMF revealed similar characteristics including heavy symptomatic burden (57% and 52%), presence of splenomegaly (43% and 55%), leukoerythroblastic blood smear (38% and 45%), and median hemoglobin (12.8 g/dL and 11.1 g/dL).
Conclusion: MPN progression represents a biological spectrum and definitions of progression in ET/PV may benefit from criteria not restricted by degree of fibrosis.

• 出版日期2015-7