title: Thrombopoietin levels increased in patients with severe acute respiratory syndrome.
abstract: Hematological changes in patients with Severe Acute Respiratory Syndrome (SARS) are common and frequently include thrombocytopenia. Using a ELISA method, we found an increase in thrombopoietin (TPO) levels in the plasma of convalesced SARS patients (290+/-53 pg/ml) and active SARS patients (251+/-23 pg/ml) comparing to that from normal control patients (228+/-17 pg/ml). In addition, the plasma from active SARS patients had an inhibitory effect on CFU-MK formation, which could be neutralized by anti-TGF-beta antibodies. In the experiment to determine whether SARS-CoV can directly infect hematopoietic stem cells and megakaryocytic cells, incubation of the cells with SARS-CoV did not show active infection. Our findings of increased TPO levels in the plasma of SARS patients provide a possible explanation for the genesis of thrombocytosis, which frequently develops from thrombocytopenia in SARS patients.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China. yangmo@hkucc.hku.hk
authors.forename: Mo
authors.initials: M
authors.lastname: Yang
authors.forename: Margaret H L
authors.initials: MH
authors.lastname: Ng
authors.forename: Chi Kong
authors.initials: CK
authors.lastname: Li
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.forename: Jie Yu
authors.initials: JY
authors.lastname: Ye
authors.forename: Beng H
authors.initials: BH
authors.lastname: Chong
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D012044:Regression Analysis; D045473:Severe acute respiratory syndrome-related coronavirus / Q000378:metabolism; D045169:Severe Acute Respiratory Syndrome / Q000097:blood* / Q000821:virology; D013234:Stem Cells; D013921:Thrombocytopenia / Q000097:blood / Q000235:genetics; D013926:Thrombopoietin / Q000096:biosynthesis*; D016212:Transforming Growth Factor beta / Q000276:immunology
chemical_list: D018952:Antigens, CD34; D016212:Transforming Growth Factor beta; D013926:Thrombopoietin