title: Acquired Glanzmann's thrombasthenia caused by glycoprotein IIb/IIIa autoantibodies of the immunoglobulin G1 (IgG1), IgG2 or IgG4 subclass: a study in six cases.
abstract: BACKGROUND
  Acquired Glanzmann's thrombasthenia (GT) is an uncommon bleeding disorder caused by glycoprotein (GP) IIb/IIIa-specific autoantibodies. Covering of the fibrinogen binding site of GPIIb/IIIa results in a moderate-to-severe bleeding tendency.
  
  
  METHODS
  We performed a diagnostic evaluation and evaluated the underlying risk factors in six patients with a bleeding tendency caused by acquired GT.
  
  
  RESULTS
  One patient, with GPIIb/IIIa autoantibodies of the immunoglobulin G2 (IgG2) subclass, used diclophenac and recovered after discontinuation of this drug. A second patient was primarily diagnosed with multiple angiodysplastic lesions. In this patient, the acquired GT was caused by GPIIb/IIIa autoantibodies of the IgG4 subclass that was treated with DDAVP and platelet transfusions. A third patient with Hodgkin's lymphoma and anti-GPIIb/IIIa of the IgG2 subclass was treated for haemorrhagic diathesis with corticosteroids and azathioprin. A fourth patient, with IgG2 anti-GPIIb/IIIa autoantibodies, diagnosed with mantle cell lymphoma, responded well to treatment of an axillary mass with local radiotherapy. The fifth and sixth patients, with IgG1 anti-GPIIb/IIIa autoantibodies, appeared to have GT after splenectomy because of autoimmune thrombocytopenia. They were treated with corticosteroids, intravenous immunoglobulin and Rituximab.
  
  
  CONCLUSIONS
  Although it might be a rare event, one should be aware of acquired GT as a cause of an unexpected primary disorder of haemostasis in patients with lymphoma or autoimmune disease. The lack of platelet destruction in these cases of acquired GT can be explained, either by the subclass of the autoantibodies (i.e. IgG2 or IgG4) or by the arrested platelet destruction by IgG1 (or IgG3) autoantibodies after splenectomy.
authors.affiliation: Immunohematology Diagnostic Services Department, Sanquin Diagnostic Services, Amsterdam, The Netherlands. l.porcelijn@sanquin.nl
authors.forename: L
authors.initials: L
authors.lastname: Porcelijn
authors.forename: E
authors.initials: E
authors.lastname: Huiskes
authors.forename: R
authors.initials: R
authors.lastname: Maatman
authors.forename: A
authors.initials: A
authors.lastname: de Kreuk
authors.forename: M
authors.initials: M
authors.lastname: de Haas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology; D005260:Female; D006487:Hemostasis; D006801:Humans; D007074:Immunoglobulin G; D008223:Lymphoma / Q000150:complications; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology*; D013915:Thrombasthenia / Q000209:etiology* / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D019039:Platelet Glycoprotein GPIIb-IIIa Complex