Objective: To determine the autonomous proliferation of erythroid stem cells in in vitro colony formation in the diagnosis of PV.
Material and Methods: Bone marrow (15 ml) was collected from thirty-five patients with suspected of PV (Hct > 50%) from the Hematology Clinic of Songklanagarind Hospital between January 2000 and December 2003. Mononuclear cells were isolated for colony assay, cultured at 4x10⁶cell/ml with and without erythropoietin in alpha modification media and fetal calf serum incubated at 37^๐C in 5% CO2. Erythroid colonies were stained with benzidine and scored on the 7^th day of culture for the CFU-E (colony forming unit-erythroid) and on the 14^thday of culture for the BFU-E (burst forming unit-erythroid).
Results: Thirty-one of the 35 patients with PV showed spontaneous in vitro colony formation (CFU-E, BFU-E) by erythroid stem cells, and colony growth without the addition of exogenous erythropoietin in the culture - a common finding in myeloproliferative disorder. The other four patients with secondary erythrocytosis had no autonomous growth of in vitro colony formation.
Conclusion: The results showed a diagnostic use for autonomous proliferation of erythroid stem cells in in vitro colony formation (CFU-E, BFU-E) in PV, even though patients were treated with phlebotomy, and other secondary erythrocytosis could be separated from PV.