Both splenic CD5(+) B and CD5(-) B cells produce platelet glycoprotein-specific autoantibodies in chronic ITP.
The objective of the present study is to determine splenic B-cell subsets and the ability of splenic CD5(+) B and CD5(-) B cells to produce platelet glycoprotein-specific autoantibodies in chronic idiopathic thrombocytopenic purpura (ITP). Splenic CD5(+) B cells were identified by two-color flow cytometric analysis in eight ITP patients. Magnetic activated cell sorting (MACS) purified splenic CD5(+) B cells and CD5(-) B cells were cultured separately in vitro. Glycoprotein-specific autoantibodies in culture supernatants and plasma were measured by modified monoclonal antibody immobilization of platelet antigen (MAIPA) assay. The percentage of splenic CD5(+) B cells in ITP patients was slightly higher than that in controls, with no statistical significance. Four ITP patients displayed plasma IgG autoantibodies against both GPIIb/IIIa and GPIb. Moreover, splenic CD5(+) B cells and CD5(-) B cells from these four ITP patients also produced high level of IgG anti-GPII(b)/III(a) and anti-GPI(b) antibodies. However, we were unable to detect IgM GP-specific autoantibodies in culture supernatant and plasma in these ITP patients. It is concluded that both splenic CD5(+) B cells and CD5(-) B cells produce platelet IgG GP-specific autoantibodies, and may all play a role in the pathogenic process of ITP.
Hou
Ming
M
Department of Haematology, Qilu Hospital, Shandong University, Jinan, Shandong, 250012, PR China. houming2@hotmail.com
Lv
Baojun
B
He
Qingsi
Q
Lu
Lu
L
Shi
Yan
Y
Ji
Xuebin
X
Ma
Daoxin
D
Zhang
Maohong
M
D000293:Adolescent; D000328:Adult; D000918:Antibody Specificity; D001323:Autoantibodies / Q000096:biosynthesis* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D018956:CD5 Antigens / Q000032:analysis; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000276:immunology*; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D013154:Spleen / Q000473:pathology*; D013156:Splenectomy
D001323:Autoantibodies; D001324:Autoantigens; D018956:CD5 Antigens; D007074:Immunoglobulin G; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex