Two human monoclonal antiplatelet autoantibodies established from patients with chronic idiopathic thrombocytopenic purpura.
Two human hybridomas secreting antiplatelet autoantibodies were established by somatic cell fusion using splenocytes from two patients with chronic idiopathic thrombocytopenic purpura (ITP). These monoclonal antibodies, HT7F and HT8C, were of the IgM isotype and reacted with autologous and allogeneic platelets fixed with paraformaldehyde (PFA). They also bound to fresh platelets. An elution study showed that eluates from allogeneic platelets reacted with autologous platelets. These results indicated that HT7F and HT8C were autoantibodies recognizing a site on the platelet surface. Both monoclonal antibodies were able to induce complement activation in vitro. HT7F was demonstrated to bind to a platelet protein having a molecular mass of 105 kDa under both nonreducing and reducing conditions. No human hybridoma synthesizing antibody against 105 kDa platelet protein has been reported to date. These antibodies may play a role in the pathogenesis of thrombocytopenia in some ITP patients.
Department of Internal Medicine and Clinical Research, Kure National Hospital, Japan.
S
S
Honda
T
T
Tsubakio
Y
Y
Tomiyama
H
H
Take
T
T
Furubayashi
H
H
Mizutani
Y
Y
Kurata
T
T
Yonezawa
S
S
Tarui
D000328:Adult; D000911:Antibodies, Monoclonal / Q000096:biosynthesis*; D001323:Autoantibodies / Q000096:biosynthesis*; D001792:Blood Platelets / Q000276:immunology*; D001798:Blood Proteins / Q000378:metabolism; D002908:Chronic Disease; D003176:Complement C3 / Q000378:metabolism; D000939:Epitopes / Q000032:analysis; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007963:Leukocytes, Mononuclear / Q000276:immunology; D011696:Purpura, Thrombocytopenic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D001798:Blood Proteins; D003176:Complement C3; D000939:Epitopes