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Cardiac xenotransplantation technology provides materials for improved bioprosthetic heart valves.
McGregor, Christopher G A; Carpentier, Alain; Lila, Nermine; Logan, John S; Byrne, Guerard W.
Afiliação
  • McGregor CG; Department of Cardiothoracic Surgery, University College London, London, United Kingdom. mcgregor.christopher@mayo.edu
J Thorac Cardiovasc Surg ; 141(1): 269-75, 2011 Jan.
Article em En | MEDLINE | ID: mdl-21168032
OBJECTIVES: Human subjects and Old World primates have high levels of antibody to galactose-α-1,3 galactose ß-1,4-N-acetylglucosamine (α-Gal). Commercially available bioprosthetic heart valves of porcine and bovine origin retain the Gal antigen despite current processing techniques. Gal-deficient pigs eliminate this xenoantigen. This study tests whether binding of human anti-Gal antibody effects calcification of wild-type and Gal-deficient glutaraldehyde-fixed porcine pericardium by using a standard subcutaneous implant model. METHODS: Expression of α-Gal was characterized by lectin Griffonia simplicifolia-IB4 staining. Glutaraldehyde-fixed pericardial disks from Gal-positive and Gal-deficient pigs were implanted into 12-day-old Wistar rats and 1.5-kg rabbits with and without prelabeling with affinity-purified human anti-Gal antibody. Calcification of the implants was determined after 3 weeks by using inductively coupled plasma spectroscopy. RESULTS: The α-Gal antigen was detected in wild-type but not Gal-deficient porcine pericardium. Wild-type disks prelabeled with human anti-Gal antibody exhibited significantly greater calcification compared with that seen in antibody-free wild-type samples (mean ± standard error of the mean: 111 ± 8.4 and 74 ± 9.6 mg/g, respectively; P = .01). In the presence of anti-Gal antibody, a significantly greater level of calcification was detected in wild-type compared with GTKO porcine pericardium (111 ± 8.4 and 55 ± 11.8 mg/g, respectively; P = .005). Calcification of Gal-deficient pericardium was not affected by the presence of anti-Gal antibody (51 ± 9.1 and 55 ± 11.8 mg/g). CONCLUSIONS: In this model anti-Gal antibody accelerates calcification of wild-type but not Gal-deficient glutaraldehyde-fixed pericardium. This study suggests that preformed anti-Gal antibody present in all patients might contribute to calcification of currently used bioprosthetic heart valves. Gal-deficient pigs might become the preferred source for new, potentially calcium-resistant bioprosthetic heart valves.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Pericárdio / Trissacarídeos / Bioprótese / Calcinose / Próteses Valvulares Cardíacas / Antígenos Heterófilos / Implante de Prótese de Valva Cardíaca Tipo de estudo: Prognostic_studies Limite: Animals / Humans Idioma: En Ano de publicação: 2011 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Pericárdio / Trissacarídeos / Bioprótese / Calcinose / Próteses Valvulares Cardíacas / Antígenos Heterófilos / Implante de Prótese de Valva Cardíaca Tipo de estudo: Prognostic_studies Limite: Animals / Humans Idioma: En Ano de publicação: 2011 Tipo de documento: Article