Cardiac valve endothelial cells: relevance in the long-term function of biologic valve prostheses.
OBJECTIVE
For reasons that are still unclear, biologic heart valve prostheses undergo degeneration after implantation. We studied the possible role of the immune system in this process.


METHODS
We examined the expression of immunologically relevant molecules by human cardiac valve endothelium in situ and in vitro and studied re-endothelialization of implanted allogeneic and xenogeneic valvular surfaces using explanted bioprostheses and valves obtained from donor hearts at cardiac retransplantation.


RESULTS
We demonstrate that human cardiac valve endothelial cells express molecules capable of initiating immune responses and might therefore play a role in the degeneration of viable cardiac valve prostheses. Also, we show evidence of re-endothelialization on the surfaces of xenografts and allografts but not on valves obtained from previously transplanted hearts.


CONCLUSIONS
Inasmuch as valves from previously transplanted hearts seem to be free from degeneration, we conclude that reduction of the immunogenicity of allograft valve prostheses by HLA matching or immunosuppressive treatment might further improve long-term results after allograft valve replacement.
Department of Cardiovascular Surgery, University Hospital, Christian Albrechts Universität zu Kiel, Germany.
A
A
Simon
M
M
Wilhelmi
G
G
Steinhoff
W
W
Harringer
P
P
Brücke
A
A
Haverich
D015703:Antigens, CD / Q000032:analysis; D001022:Aortic Valve Insufficiency / Q000276:immunology / Q000601:surgery; D001705:Bioprosthesis; D002478:Cells, Cultured; D004699:Endocardium / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology*; D019544:Equipment Failure Analysis; D006084:Graft Rejection / Q000276:immunology / Q000601:surgery; D016027:Heart Transplantation / Q000276:immunology; D006350:Heart Valve Prosthesis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006650:Histocompatibility Testing; D006801:Humans; D007124:Immunoenzyme Techniques; D011183:Postoperative Complications / Q000276:immunology*; D012086:Reoperation; D014841:von Willebrand Factor / Q000032:analysis
D015703:Antigens, CD; D000949:Histocompatibility Antigens Class II; D014841:von Willebrand Factor