title: In vitro studies of human pluripotential hematopoietic progenitors in polycythemia vera. Direct evidence of stem cell involvement.
abstract: Previous in vitro studies on committed hematopoietic progenitors have suggested that polycythemia vera (PV) is a clonal disorder arising in a pluripotential hematopoietic stem cell. In this study, recently developed technics for clonal assay of a human multipotential progenitor cell (CFU-GEMM) were used to assess the functional characteristics of CFU-GEMM in 19 PV patients. These studies showed: (a) increased numbers of detectable CFU-GEMM in blood and bone marrow samples of PV patients as compared with normals (P less than 0.002 and P less than 0.02, respectively); (b) erythropoietic differentiation of PV CFU-GEMM without exogenous erythropoietin (Ep) in culture (in marked contrast to CFU-GEMM of both normals and subjects with secondary erythrocytosis which require exogenous Ep for terminal hemoglobinization of their erythroid component), a property shown by experiments with an anti-Ep antiserum to be related to increased sensitivity of PV CFU-GEMM to Ep; (c) increased megakaryocyte formation by PV CFU-GEMM as compared with normals (P less than 0.025); and (d) a linear relationship, extrapolating to the origin, between CFU-GEMM detected and cells cultured. These studies demonstrate that at least two clinical features of PV, increased erythropoiesis and megakaryocytopoiesis, are reflected in corresponding functional characteristics of PV CFU-GEMM, and provide direct evidence of distinctive pluripotential stem cell activity in this disorder.
mesh_terms: D001853:Bone Marrow / Q000473:pathology; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D004920:Erythropoiesis; D004921:Erythropoietin / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008533:Megakaryocytes / Q000502:physiology; D011087:Polycythemia Vera / Q000473:pathology* / Q000503:physiopathology
chemical_list: D004921:Erythropoietin