title: Acquired myopathic intestinal pseudo-obstruction may be due to autoimmune enteric leiomyositis.
abstract: We describe a previously healthy boy who developed intestinal pseudo-obstruction following an episode of gastroenteritis at age 2 years. At presentation, the patient had mildly raised erythrocyte sedimentation rate and C-reactive protein level, and elevated antineutrophil cytoplasmic antibodies, antinuclear anti-DNA, and anti-smooth muscle antibodies. His electrogastrography was myopathic with no dominant frequency. First full-thickness intestinal biopsies showed a T lymphocytic myositis, particularly in the circular muscle. Steroid therapy resulted in clinical remission; cessation of steroids, in relapse. Further full-thickness biopsies showed an initial reduction in alpha-smooth muscle actin immunostaining in circular muscle myocytes and later atrophy and disappearance of many myocytes. Vascular and the remaining enteric smooth muscle cells showed HLA-DR and intercellular adhesion molecule 1 expression. These observations demonstrate the ability of enteric myocytes to take part in an inflammatory response and to change their phenotype, allowing them to act as antigen-presenting cells and to activate T cells. This and possible cytokine production by the myocytes play a role in their own destruction. This process responded to immunosuppressive therapy.
authors.affiliation: Department of Paediatric Gastroenterology, Great Ormond Street Hospital, London, England.
authors.forename: Tarja H
authors.initials: TH
authors.lastname: Ruuska
authors.forename: Riitta
authors.initials: R
authors.lastname: Karikoski
authors.forename: Virpi V
authors.initials: VV
authors.lastname: Smith
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Milla
mesh_terms: D001327:Autoimmune Diseases / Q000150:complications*; D001706:Biopsy; D002675:Child, Preschool; D003106:Colon / Q000473:pathology; D005759:Gastroenteritis / Q000150:complications / Q000276:immunology / Q000473:pathology; D006801:Humans; D007082:Ileum / Q000473:pathology; D007418:Intestinal Pseudo-Obstruction / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D008297:Male; D009220:Myositis / Q000150:complications* / Q000276:immunology / Q000473:pathology