title: Bleeding tendency caused by IgG inhibitor to factor XIII, treated successfully by cyclophosphamide.
abstract: A case exhibiting bleeding tendency caused by an acquired inhibitor to factor XIII is reported. The patient, a hitherto healthy 87-year-old Japanese man, presented with a massive subcutaneous bleeding, leading to severe anaemia. The routine coagulation study was normal except for a decreased plasma factor XIII level, which was 3% of the control level by the dansylcadaverine incorporation assay. An inhibitor of factor XIII was demonstrated to be present in the IgG fraction of the patient's plasma; by immunoblotting this inhibitor was shown to bind specifically the a and a' subunits of factor XIII. The IgG fraction suppressed the transglutaminase activity of activated factor XIII, but did not inhibit the molecular transformation of subunit a to a' in the activation process. Massive infusion of plasma and factor XIII concentrate was effective for controlling the bleeding temporarily. In the long-term prednisolone was ineffective for suppressing the plasma inhibitor level and bleeding episodes recurred. A small daily dose (50 mg) of cyclophosphamide, however, effectively decreased the inhibitor level and controlled bleeding.
authors.affiliation: First Department of Medicine, Tokyo Medical/Dental University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: A
authors.initials: A
authors.lastname: Kato
authors.forename: Y
authors.initials: Y
authors.lastname: Sakata
authors.forename: N
authors.initials: N
authors.lastname: Aoki
mesh_terms: D000368:Aged; D003520:Cyclophosphamide / Q000627:therapeutic use*; D015944:Factor VIIIa; D005176:Factor XIII / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006474:Hemorrhagic Disorders / Q000188:drug therapy*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology* / Q000378:metabolism; D008297:Male
chemical_list: D007074:Immunoglobulin G; D015944:Factor VIIIa; D003520:Cyclophosphamide; D005176:Factor XIII