JPGN Reports · 3 authors, 3 centres
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A 16-year-old girl developed hereditary angioedema (HAE) after receiving a liver transplant as an infant, likely acquired from the donor. Her symptoms—severe episodic abdominal pain—resolved with C1 esterase inhibitor replacement therapy. This case highlights that liver transplantation can transmit inborn errors of metabolism from donor to recipient, and that recurrent abdominal pain in children may be a presentation of HAE.
**Background:** Liver transplantation is standard for end-stage liver disease and increasingly used for inborn errors of metabolism (IEM). However, transplantation can also inadvertently transmit IEM from donor to recipient. Hereditary angioedema (HAE) is a rare autosomal dominant disorder (incidence 1:70,000) caused by C1 esterase inhibitor (C1-INH) deficiency, typically due to SERPING1 mutations. C1-INH is primarily produced in the liver. HAE presents with episodic nonpruritic edema of the skin, submucosal edema of the upper airways (potentially fatal), and submucosal bowel edema causing abdominal pain, nausea, vomiting, or bowel obstruction. Diagnosis is often delayed 8–22 years from first episode.
**Methods:** This is a single case report of a 16-year-old Caucasian girl who received a whole graft liver transplant at 12 months of age for end-stage liver disease due to Progressive Familial Intrahepatic Cholestasis type 3. The donor was a neonate with anencephaly who died from global cerebral hypoxia. The patient developed intermittent colicky abdominal pain at age 7 (6 years post-transplant), occurring at least weekly, lasting about an hour, and resolving spontaneously. Pain was unrelated to meals or exercise and not associated with nausea, vomiting, or diarrhea. Episodes became increasingly frequent and disruptive in adolescence. No peripheral swelling or rashes were observed. Investigations including full blood count, inflammatory markers, pancreatic enzymes, abdominal Doppler ultrasound, upper gastrointestinal endoscopy, and barium meal with follow-through were all normal. Graft function remained stable (AST 61 U/L [10–50], ALT 41 U/L [0–45], GGT 15 U/L [0–45]), though serum albumin was slightly low at 32 g/L [35–51]). Complement C4 was low at 0.06 g/L [0.13–0.52]; C3 was normal at 0.75 g/L [0.75–1.75]. C1-INH level was low at 0.12 g/L [0.19–0.40] with abnormal function, confirming HAE. Parents had normal C4 levels (father 0.17 g/L, mother 0.29 g/L).
**Key Results:** Treatment with C1-INH replacement therapy (Berinert, 1000 units intravenously twice weekly) was started at age 14, resulting in complete resolution of abdominal pain. Therapy was weaned to weekly injections after 8 months and ceased after 4 more months. Symptoms recurred 4 months after cessation and responded to reinstitution of treatment. The patient currently uses C1-INH therapy on demand. Notably, transaminases increased when C1-INH therapy was stopped and improved after restarting. Liver biopsy at that time showed no significant evidence of acute cellular rejection.
**Clinical Implications:** This case illustrates that HAE can be acquired via liver transplantation from an asymptomatic donor, as the patient's parents had normal C4 levels and no HAE. Two other publications have reported HAE acquired via liver transplant: one abstract reporting a series of 18 patients with acquired HAE (one via liver transplant) and one report of an adult developing C1-INH deficiency after liver transplant. The case highlights two key points: (1) liver transplantation can transfer rare hepatic-derived synthetic proteins and enzymes, especially when the donor has subtle or no symptoms; (2) recurrent severe abdominal pain in children can be a manifestation of HAE. C1-INH replacement therapy was effective in controlling symptoms and appeared to improve liver transaminase levels, possibly reflecting hepatic involvement in HAE.