HEPATIC VEIN THROMBOSIS
A 14-year-old male presents with sudden onset of left upper quadrant abdominal pain. Doppler ultrasound reveals a hepatic vein thrombosis. His past medical history is significant for aplastic anemia, which was diagnosed at age 10. He was treated with antithymocyte antiglobulin and cyclosporine, with good recovery of his counts. His current blood counts are all within normal ranges.
What laboratory test will be likely to reveal an etiology for his thrombosis?
A. Protein C
B. Factor V Leiden
C. Bone marrow biopsy
D. Homocysteine levels
E. Flow cytometry
ANSWER ON TUESDAY 10 AM
E
ReplyDeleteIdiopathic thrombosis in males is extremely rare. The differential diagnosis includes underlying genetic thrombophilias and drug effects, but should also include paroxysmal nocturnal hemoglobinuria (PNH), a clonal disease characterized by chronic intravascular hemolysis and recurrent thrombosis. This patient most likely has PNH.
ReplyDeleteOnly about 25% of patients present with classic nocturnal hemoglobinuria. Patients with aplastic anemia and thromboses involving unusual sites should all be screened for PNH. In particular, PNH has been shown to develop more commonly in patients successfully treated with an antithymocyte antiglobulin and cyclosporine. Diagnosis has traditionally been made with a Ham acid test, which detects complement mediated hemolysis. However, flow cytometry has become the standard for diagnosis.
Protein C, factor V Leiden, and homocysteine levels are associated with prothrombotic states; however, given this patient’s history of aplastic anemia, PNH is the more likely diagnosis.
SO CORRECT ANSWER IS ‘E’