title: C1-esterase inhibitor deficiency in pediatric heart transplant recipients: incidence and findings on ultrasound.
abstract: BACKGROUND
  Acquired angioedema of the bowel caused by a deficiency of C1-esterase inhibitor can lead to severe abdominal pain with sudden onset, mimicking an acute surgical abdomen. In contrast to hereditary angioedema, which usually manifests in childhood, acquired angioedema is broadly recognized to affect people older than 40 years.
  
  
  OBJECTIVE
  To determine the incidence of acquired angioedema in a cohort of pediatric heart transplant recipients and assess imaging findings on ultrasonography.
  
  
  METHODS
  A cohort of 207 children and adolescents who had undergone heart transplantation were assessed at regular follow-up examinations for incidence of acquired angioedema. All patients received ACE inhibitors and immune inhibitors. Control examinations carried out in 3-month intervals included history, assessment of clinical symptoms, physical examination, US of the abdomen and laboratory blood analysis. In addition, if clinical symptoms were newly encountered, children were admitted between regularly scheduled intervals. We analyzed results of abdominal US for pathological findings of the bowel, and we assessed imaging findings in children diagnosed with acquired angioedema.
  
  
  RESULTS
  Acquired angioedema was diagnosed in 3/207 patients (2 girls ages 16 and 17 years and 1 boy age 9 months). These children presented with sudden onset of severe abdominal pain. The bowel wall was thickened in the presence of ascites. After a mean of 72 h, abdominal pains resolved. Thickening of bowel loops dissolved and ascites disappeared.
  
  
  CONCLUSIONS
  Single episodes of acquired angioedema were encountered in 1.4% of our series of pediatric heart transplant recipients. Radiologists should be familiar with this disease so they can diagnose it on US imaging.
authors.affiliation: Department of Pediatric Radiology, University Hospital Giessen, Justus Liebig University Giessen, Klinikstrasse 33, 35392, Giessen, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Pabst
authors.forename: Nadja
authors.initials: N
authors.lastname: Hamscho
authors.forename: Fritz
authors.initials: F
authors.lastname: Roller
authors.forename: Holger
authors.initials: H
authors.lastname: Stracke
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schranz
authors.forename: Claudia
authors.initials: C
authors.lastname: Lämmler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Alzen
authors.forename: Gabriele A
authors.initials: GA
authors.lastname: Krombach
mesh_terms: D000006:Abdomen, Acute / Q000175:diagnosis / Q000453:epidemiology*; D000293:Adolescent; D054179:Angioedemas, Hereditary / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015984:Causality; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D005858:Germany / Q000453:epidemiology; D016027:Heart Transplantation / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007410:Intestinal Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014463:Ultrasonography / Q000706:statistics & numerical data*