Acquired Bernard-Soulier syndrome. Evidence for the role of a 210,000-molecular weight protein in the interaction of platelets with von Willebrand factor.
A patient with a lymphoproliferative disorder developed bleeding associated with a prolonged bleeding time and a selective defect of platelet aggregation in response to ristocetin. The patient's purified IgG was shown to inhibit aggregation of washed normal platelets by ristocetin and von Willebrand factor (F VIII:vWF). By Western blotting, it was shown that antibody bound specifically to an antigen of Mr 210,000 present on normal platelets but missing on platelets from patients with congenital Bernard-Soulier syndrome (BSS). Binding was effected by the F(ab)2 portion of the IgG, indicating the presence of an autoantibody rather than an immune complex. These results suggest that the 210,000-Mr protein is involved in the interaction of F VIII:vWF with platelets. Furthermore, we have demonstrated the apparent absence of an additional protein on congenital BSS platelets. Heat-aggregated IgG was also shown to bind to the 210,000-Mr protein, suggesting that this protein may function as an Fc receptor on platelets. The relationship of the 210,000-Mr protein to glycoprotein Ib and the precise role of this protein in the interaction of platelets with F VIII:vWF need to be characterized.
Stricker
R B
RB
Wong
D
D
Saks
S R
SR
Corash
L
L
Shuman
M A
MA
D000328:Adult; D001323:Autoantibodies / Q000502:physiology; D001606:Bernard-Soulier Syndrome / Q000097:blood* / Q000276:immunology; D001666:Binding Sites, Antibody; D001760:Bleeding Time; D001791:Blood Platelet Disorders / Q000097:blood*; D001792:Blood Platelets / Q000276:immunology / Q000502:physiology*; D006023:Glycoproteins / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G / Q000502:physiology; D008297:Male; D008565:Membrane Proteins / Q000276:immunology / Q000502:physiology*; D008970:Molecular Weight; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins; D014841:von Willebrand Factor / Q000502:physiology*
D001323:Autoantibodies; D006023:Glycoproteins; D007074:Immunoglobulin G; D008565:Membrane Proteins; D010980:Platelet Membrane Glycoproteins; D014841:von Willebrand Factor