title: Demonstration of TGF-β and XIIIαin Endocardial Biopsies of Carcinoid Heart Disease Patients: an Immunofluorescence Study.
abstract: BACKGROUND
  Serotonin and other vasoactive substances play a critical role in the development of carcinoid heart disease, but the exact etiology of the illness is still unknown.
  
  
  METHODS
  By using immunofluorescence microscopy, we investigated the expression of transforming growth factor-β (TGF-β) and the presence of fibrin-stabilizing factor (XIIIα) in endomyocardial biopsy specimens of patients with carcinoid heart disease. In addition, the tissue integrity of the specimens was studied by staining for laminin.
  
  
  RESULTS
  Both TGF-β and XIIIαco-localized in the endocardium beneath carcinoid plaques: while TGF-β was found within myocytes, XIIIαwas detected on the surface of cells in fibrotic lesions stretching out into the tissue. Laminin staining revealed that the integrity of the endocardium was dissolved and that the tissue consisted of hypertrophic and hypotrophic myocytes.
  
  
  CONCLUSIONS
  The results suggest that the presence of TGF-β and XIIIαin carcinoid heart lesions indicates that endocardial damage induced by serotonin and other vasoactive substances gives rise to an overshooting wound healing process.
authors.affiliation: Internal Medicine - Cardiology, Philipps University, Marburg, Germany; Group Practice for Cardiology Papenburg, Papenburg, Germany.
authors.forename: Dorgrit
authors.initials: D
authors.lastname: Diepholz
authors.affiliation: Internal Medicine - Cardiology, Philipps University, Marburg, Germany; Group Practice for Cardiology Papenburg, Papenburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wilke
authors.affiliation: Internal Medicine - Cardiology, Philipps University, Marburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Maisch
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, U.K.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Steverding
keywords: Carcinoid heart disease; Fibrin-stabilizing factor; Transforming growth factor-β