title: Acquired Factor XIII inhibitor associated with mantle cell lymphoma.
abstract: Acquired Factor (F)XIII deficiency is a very rare bleeding diathesis with a potentially fatal outcome, previously described in the context of autoimmune disorders and leukemias. There is minimal information on autoantibody characterization and the role of antifibrinolytic therapy in patient management.
  
  
  
  A 79-year-old woman with a 3-month history of bruising and heavy menorrhagia presented with ongoing vaginal bleeding, symptomatic anemia, and a right thigh hematoma. Initial management included an axillary lymph node biopsy and coagulation evaluation. Pathologic examination of the biopsy specimen revealed mantle cell lymphoma. Clot solubility assay was consistent with a FXIII activity of less than 3%. An anti-FXIII inhibitor was suspected, the epitope specificity of which was mapped by micropeptide array analysis to regions in the β-sandwich and catalytic core domain of the FXIII-A subunit. Management with cryoprecipitate, steroids, rituximab, and antifibrinolytic therapy resolved the bleeding diathesis and suppressed the inhibitor.
  
  
  
  This is the first reported case of an acquired FXIII inhibitor associated with mantle cell lymphoma in which the epitope specificity of the pathologic autoantibody was accurately defined. Antifibrinolytic therapy played a prominent role in the prevention of bleeding complications in the window period between initiation of immunosuppression and disappearance of the pathologic anti-FXIII autoantibody.
authors.affiliation: Center for International Health Research, Rhode Island Hospital and Alpert Medical School of Brown University.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Nixon
authors.affiliation: Department of Hematology & Oncology, Rhode Island Hospital and The Miriam Hospitals.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Prsic
authors.affiliation: Department of Coagulation, Rhode Island Hospital.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Guertin
authors.affiliation: Department of Hematology & Oncology, Rhode Island Hospital and The Miriam Hospitals.
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Stevenson
authors.affiliation: Department of Transfusion Medicine, Rhode Island Hospital and The Miriam Hospitals, Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Sweeney
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D019774:Blood Coagulation Factor Inhibitors / Q000097:blood / Q000276:immunology; D000939:Epitopes / Q000097:blood / Q000276:immunology; D005176:Factor XIII / Q000276:immunology / Q000378:metabolism; D005177:Factor XIII Deficiency / Q000097:blood / Q000209:etiology / Q000276:immunology; D005260:Female; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000097:blood / Q000276:immunology
chemical_list: D001323:Autoantibodies; D019774:Blood Coagulation Factor Inhibitors; D000939:Epitopes; D005176:Factor XIII