A 94-year-old Female with chronic kidney disease (stage 4), recurrent urinary tract infections (UTIs), and hypertension presented with a 3 day history of worsening general weakness, left thigh soreness, and a left thigh hematoma which was noted by the home health aide. The patient had a hospitalization 1 month prior in which she was noted to have a UTI and a drop in hemoglobin (from admission Hg of 10.6g/dL to 6.7g/dL) requiring blood transfusion. The patient deferred GI work-up at the time. On arrival to the emergency department vital signs were stable. Physical exam revealed a posterior left thigh hematoma expanding from the bottom of the buttock to the knee. Blood results revealed a hemoglobin of 9.6g/dL, an elevated PTT of 71.0 sec (upper limit of normal: 37.4 s), and a normal INR and aPTT. The patient required two units of blood and her hemoglobin remained stable. A mixing study revealed partial correction with a PTT of 65.2. Further workup demonstrated a Factor VIII assay as <1, and normal levels of Von Willebrand factors. These studies indicate the presence of an acquired factor VIII inhibitor. The patient was started on a steroid taper (starting dose 1mg/kg daily) and her red blood cell indices remained stable throughout the remainder of the hospital course.
Discussion:
Acquired Hemophilia A (AHA) is a rare disease, with 1.5 cases per million patients. AHA occurs more commonly in older age. Typical conditions associated with AHA are autoimmune disorders, malignancy, and pregnancy, but 50% of cases can be idiopathic. Patients typically present with spontaneous hemorrhages, including hematoma into muscles and soft issue, epistaxis, and hematuria. Early diagnosis is crucial as significant bleeding is what attributes to its high mortality. There are two parts to treatment: hemostatic therapy and elimination of the inhibitor. Depending on the severity of the bleeding, DDAVP, recombinant factor VIII or VIIa, or activated prothrombin complex concentrate can be used. Patients are still prone to bleeding until the inhibitor is eliminated with immunosuppressive therapy. Treatment with cyclophosphamide in addition to steroids has been shown to be superior in achieving remission compared to steroids alone, however no differences in survival were found. Ongoing research is investigating alternative therapy options, such as rituximab, as a second line treatment. Prompt treatment and recognition of the disorder is vital in order to stabilize the bleeding.
Conclusions:
While older patients are more likely to have AHA, they are more likely to go undiagnosed. This is particularly important in older adults who often present with hematomas often attributed to falls and medications. Hospitalists should think of AHA when a patient is presenting with an unexplained bleed and isolated elevated PTT levels.