Successful resolution of bowel obstruction in a patient with hereditary angioedema

Hereditary angioedema (HAE), a rare genetic disorder caused by a deficiency of the C1 esterase inhibitor, leads to an episodic, self-limiting increase in vascular permeability. Related symptoms commonly include recurrent, intractable abdominal pain, vomiting, and/or diarrhea. DX-88 (ecallantide), a 60-amino acid recombinant protein discovered through phage display technology, is a highly specific, potent inhibitor of human plasma kallikrein that has been used successfully in the treatment of patients experiencing acute HAE attacks. This case study involves a 65-year-old woman who presented with severe abdominal pain, cramping, and nausea. The study describes the use of a video obtained by capsule endoscopy for the direct imaging of bowel occlusion in a patient with HAE that resolved upon treatment with DX-88. After administration of DX-88, 80 mg intravenously, abdominal pain and nausea resolved within 30 min. Capsule endoscopy demonstrated a coincident resolution of the bowel wall edema, with a return to normal within approximately 1.5 h of DX-88 administration. This case study demonstrates that DX-88 can produce dramatic clinical benefits in a patient with an acute abdominal HAE attack, resolving both symptoms and pathologic signs. Furthermore, it illustrates the usefulness of videos obtained from capsule endoscopy in identifying the presence of bowel occlusion and demonstrating its subsequent rapid resolution upon administration of DX-88.