Case Presentation:
A 79‐year‐old man with a history notable for hyperlipidemia and stage I prostate cancer presented to his physician with fatigue and easy bruising for 3 weeks after returning from a recent 2‐month trip to Europe.
He had first noticed extensive bruising on his arms and legs while in the shower. He denied any falls or trauma to those areas.. He also denied fever, weight loss, abdominal symptoms, shortness of breath, sick contacts, or unusual exposures during his trip. On admission, his hematocrit was 21.4 mg/dL (decreased from 42.9 mg/dL 1 year previously), aPTT 66.5 seconds, total bilirubin 1.7 mg/dL with an indirect fraction > 50%, lactate dehydrogenase 339 IU/L, and haptoglobin < 5 mg/dL. Fibrinogen, fibrin degradation products, platelets, white blood cell count, and chemistry panel were within normal limits. Coombs test was negative, and a thrombin time was normal. Results of a mixing study were consistent with factor inhibition, and factor VIII levels returned at <1.5% with a high inhibitor titer of 1:819. The patient was started on prednisone and cyclo‐phosphamide for a diagnosis of acquired hemophilia A. His anemia was treated symptomatically with blood transfusions, and he was discharged with close follow‐up.
Discussion:
Acquired hemophilia, an autoimmune bleeding disorder characterized by inhibitors to factor VIII, must be considered in a patient with soft‐tissue bleeding and an elevated aPTT. The condition is rare, with an incidence of 0.2–1 case per 1 million people/year. There is a bimodal age distribution, with a small peak at 20–30 years and a larger peak at 68–80 years. Although acquired hemophilia can be associated with the postpartum period, autoimmune diseases, hematologic or solid cancers, and medications, up to 50% of cases are idiopathic. Diagnosis is made by a mixing study that does not correct with normal serum and with measurement of factor VIII levels with inhibitor activity (using the Bethesda assay). Bleeding in acquired hemophilia can often be quite severe, and patients may require transfusional support. Treatment of acute hemorrhage also entails correction of the bleeding diathesis with either replacement of factor VIII (if Bethesda Units < 5 units/mL) or with “factor VIII bypassing agents” such as recombinant activated factor VII. The long‐term management of acquired hemophilia involves inhibitor eradication with cyclophos‐phamide and prednisone. New evidence suggests a role for rituximab, an anti‐CD20 monoclonal antibody, in the treatment of acquired hemophilia. However, sufficient data have yet to support this agent's use as first‐line treatment.
Conclusions:
Acquired hemophilia is a rare autoimmune bleeding disorder that should be considered in patients with soft‐tissue bleeding and elevated aPTT. The cause is idi‐opathic in half the cases. Treatment is aimed toward inhibitor eradication and correction of the bleeding diathesis.
Disclosures:
R. Karp ‐ none; A. Vanka ‐ none