ISSN 2997-1036
International Journal of Hematology | Vol. 7, No. 5, May 2016 | pp. 33–40
DOI: 10.46882/2016/IJH/000077
Case Report
Title: Spontaneous retroperitoneal hemorrhage secondary to acquired Factor IX inhibitor development in an elderly patient
Names of Authors: K. L. Musa¹, M. N. Lawal², O. P. Dikko³
Authors’ Affiliations: ¹Department of Haematology, Federal Medical Centre, Katsina, Nigeria; ²Department of Surgery, Bayero University, Kano, Nigeria; ³Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
Abstract: Acquired hemophilia B is an exceptionally rare autoantibody-mediated bleeding disorder characterized by the development of inhibitors against coagulation Factor IX. We report a 72-year-old male who presented with sudden, severe left flank pain, lower abdominal distension, and hypovolemic shock. Abdominal computed tomography revealed a massive retroperitoneal hematoma measuring 12.4 × 8.5 cm without a history of trauma or anticoagulant exposure. Coagulation screens demonstrated an isolated, markedly prolonged activated partial thromboplastin time of 92.4 seconds that did not correct following a 1:1 mixture with normal pooled plasma, pointing to a circulating inhibitor. Factor IX activity was severely reduced to 2.0%, and a Bethesda assay quantified a Factor IX inhibitor titer of 18.0 Bethesda Units. Immediate hemostasis was achieved using recombinant activated Factor VII bypassing agents (90 μg/kg every 3 hours), combined with packed cell support. Epigenetic immunosuppressive therapy utilizing oral prednisone (1 mg/kg) paired with low-dose cyclophosphamide cleared the inhibitor by week 8. This case demonstrates that acquired Factor IX autoantibodies can cause life-threatening retroperitoneal bleeding in elderly individuals, requiring prompt deployment of bypassing therapeutics.
Keywords: Acquired hemophilia B, Factor IX inhibitor, retroperitoneal hemorrhage, Bethesda assay, bypassing agents
Manuscript Timeline: Received: February 15, 2016; Revised: March 24, 2016; Accepted: April 11, 2016; Published: May 19, 2016