title: Quantitation of RNA-dependent platelet DNA polymerase in patients with myeloproliferative disorders.
abstract: Platelets from 28 patients with the myeloproliferative diseases (MPD) polycythaemia vera (9), essential thrombocythaemia (6), myelofibrosis with myeloid metaplasia (5) and chronic myelogenous leukaemia (8) were examined for an RNA-dependent DNA polymerase activity using standardized conditions permitting highly reproducible quantitation. Low levels of activity were detected in platelets of normal individuals, but platelets of nearly all MPD patients (25/28) possessed higher levels. The polymerase activity correlated with diagnosis (P = 0.001) and did not correlate with platelet counts (P greater than 0.2). Quantitation of this RNA-dependent DNA polymerase activity may be a useful parameter in the diagnosis of myeloproliferative disorders.
mesh_terms: D001792:Blood Platelets / Q000201:enzymology*; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D007951:Leukemia, Myeloid / Q000201:enzymology; D009196:Myeloproliferative Disorders / Q000201:enzymology*; D011087:Polycythemia Vera / Q000201:enzymology; D055728:Primary Myelofibrosis / Q000201:enzymology; D012194:RNA-Directed DNA Polymerase / Q000097:blood*; D013347:Subcellular Fractions / Q000201:enzymology; D013922:Thrombocytosis / Q000201:enzymology
chemical_list: D004247:DNA; D012194:RNA-Directed DNA Polymerase