Effects of anti-platelet glycoprotein Ib and/or IIb/IIIa autoantibodies on the size of megakaryocytes in patients with immune thrombocytopenia.
To determine whether anti-platelet autoantibodies react with megakaryocytes, as well as with platelets, in immune thrombocytopenia (ITP), 38 ITP patients were studied. They were classified into four groups; anti-platelet glycoprotein Ib-positive (group A, n = 5), anti-platelet glycoprotein II/b/IIIa-positive (group B, n = 2), positive to both antibodies (group C, n = 3), and negative to both antibodies (group D, n = 28). The number and size of megakaryocytes in each group were compared. The number of megakaryocytes in groups A, B, C, and D was 12.8 +/- 8.9, 75.2, 29.1, and 17.0 +/- 21.7/mm2, respectively. The mean cytoplasmic area of megakaryocytes in groups A, B, C, and D was 1001 +/- 26.3, 1621, 1109, and 1311 +/- 235.6/micrograms2, respectively. This finding indicated that, in the presence of anti-platelet glycoprotein Ib, megakaryocytes were not increased in number and were small in size, whereas, in the presence of anti-platelet glycoprotein IIb/IIIa, megakaryocytes were increased in number and in cytoplasmic area. Our study suggested that anti-platelet glycoprotein Ib may impair platelet production by megakaryocytes in ITP.
Hasegawa
Y
Y
Division of Hematology, University of Tsukuba, Ibaraki, Japan.
Nagasawa
T
T
Kamoshita
M
M
Komeno
T
T
Itoh
T
T
Ninomiya
H
H
Abe
T
T
D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000097:blood*; D002470:Cell Survival; D003593:Cytoplasm / Q000473:pathology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008533:Megakaryocytes / Q000276:immunology / Q000473:pathology*; D010976:Platelet Count; D010980:Platelet Membrane Glycoproteins / Q000276:immunology*; D013921:Thrombocytopenia / Q000097:blood / Q000276:immunology*
D001323:Autoantibodies; D007074:Immunoglobulin G; D010980:Platelet Membrane Glycoproteins