title: The effect of costimulatory factors in the pathogenesis of chronic idiopathic thrombocytopenic purpura.
abstract: To investigate the effect of costimulatory factors in the pathogenesis of chronic idiopathic thrombocytopenic purpura (CITP), we examined the expression of CD80 on platelets and megakaryocytes in patients with CITP and the controls by FACS. By using CD80 monoclonal antibody (McAb) to inhibit interaction among cells which is mediated by costimulatory factors, we observed the effect of CD80 McAb on the growth and maturation of megakaryocytic progenitors of patients with CITP in vitro. The results showed the expression of CD80 on platelets and megakaryocytes in CITP group was significantly higher than that in controls (P<0.01). There was a significantly positive correlation between the expression of CD80 on platelets and serum PAIgG in CITP (r=0.86, P<0.05). The mean of various clone numbers (CFU-MK, BFU-MK and mCFU-MK) in CITP were all lower than those in controls (P<0.05). In megakaryocytes co-cultured with CD80 McAb, there was an increasing tendency of the number of CFU-MK and big CFU-MK (the number of megakaryocyte with GP IIIa positive was more than 20) and mediate CFU-MK (the number of megakaryocyte with GP IIIa positive was 11-20). When the concentration of CD80 McAb was 10 microg/L, there was a significant difference in the number of megakaryocytic colony formation (CFU-MK, BFU-MK and mCFU-MK) between the group with CD80 McAb and that without it (P<0.05). These showed the abnormality of costimulatory factors had important effect in the pathogenesis of CITP.
authors.affiliation: Institute of Hematology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
authors.forename: Guohui
authors.initials: G
authors.lastname: Cui
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Liu
authors.forename: Junxia
authors.initials: J
authors.lastname: Yao
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen / Q000096:biosynthesis*; D001792:Blood Platelets / Q000378:metabolism*; D002478:Cells, Cultured; D002908:Chronic Disease; D003115:Colony-Stimulating Factors / Q000378:metabolism*; D005260:Female; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D008297:Male; D008533:Megakaryocytes / Q000166:cytology / Q000378:metabolism; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000209:etiology* / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen; D003115:Colony-Stimulating Factors