title: Acquired factor VIII deficiency: two case reports and a review of literature.
abstract: BACKGROUND
  Acquired factor VIII (FVIII) deficiency, or acquired hemophilia A (AHA), is a rare autoimmune disorder involving antibody-mediated depletion of coagulation FVIII, leading to severe, life-threatening bleeding. The condition is often associated with other autoimmune disorders, and its treatment involves replacement of FVIII and various modes of immunosuppression. Recently, a few noteworthy therapeutic advances have been made. We present two cases of severe AHA in Chinese women. One of these women developed this disorder in the setting of possible parvovirus B19 infection, which has not yet been reported in association with AHA. Other notable features of her case included paradoxical venous thrombosis and possible association with Sjogren's syndrome and myositis. The other woman failed to respond to usual first-line therapies despite exhibiting a less severe clinical course, illustrating the varied but potentially stubborn behavior of this disorder.
  
  
  METHODS
  An 87-year-old woman presented with diffuse ecchymoses, melena, vaginal bleeding. Labs showed hemoglobin (Hgb) nadir of 5.7 mg/dL, elevated partial thromboplastin time (PTT), FVIII level <1%, mixing study consistent with an inhibitor, elevated anti-Sjogren's-Syndrome-related antigen A antibody, elevated creatinine kinase, and elevated parvovirus IgM and IgG. Imaging of her arm showed diffuse myositis and deep venous thrombosis. After intravenous and oral steroids, her FVIII levels normalized, and her symptoms subsided.
  
  
  METHODS
  A 59-year-old woman presented with recurrent ecchymoses and hematomas in her extremities. Labs showed Hgb of 11.7 mg/dL, elevated PTT, FVIII level of 3%, and mixing study consistent with an inhibitor. Despite receiving a long course of steroids, several courses of IVIG, and a few courses of Rituximab, her FVIII level remained critically low.
  
  
  CONCLUSIONS
  The rarity of AHA limits our understanding of this disease and the ability to perform trials to discover optimal therapies. We hope that these case reports and discussion will shed further light on the varied clinical manifestations and natural histories of this disorder to guide better recognition and treatment of AHA.
authors.affiliation: Weill Cornell Medicine, New York-Presbyterian Lower Manhattan Hospital, 170 William Street, New York, NY 10038 USA.
authors.forename: Lan
authors.initials: L
authors.lastname: Mo
authors.affiliation: Weill Cornell Medicine, New York-Presbyterian Lower Manhattan Hospital, 170 William Street, New York, NY 10038 USA.
authors.forename: George C
authors.initials: GC
authors.lastname: Bao
keywords: Acquired factor VIII deficiency; Acquired hemophilia A; Glucocorticoids; Immunosuppression; Intravenous Immunoglobulin; Myositis; Parvovirus B19; Rituximab