Alpha-Gal specific IgG immune response after implantation of bioprostheses

Thorac Cardiovasc Surg. 2009 Jun;57(4):191-5. doi: 10.1055/s-0029-1185395. Epub 2009 May 20.


Background: We have previously shown that the alpha-Gal (Galalpha1.3-Galbeta1-4GlcNAc-R) epitope is a relevant xenoantigen present on bioprostheses utilized in cardiac surgery and elicits an alpha-Gal specific IgM immune response. We sought to investigate whether that immune response continues after valve implantation.

Materials and methods: We collected plasma samples from patients who underwent bioprosthesis implantation (n = 19) or mechanical valve replacement (n = 8), respectively, prior to, at 10 days and at 3 months after cardiac surgery. ELISA was utilized to quantify alpha-Gal specific IgG and IgG subclasses. 3 bioprosthetic tissue samples were obtained from patients who had to undergo re-operation within 1 week (n = 1) or at 12-15 months (n = 2) after the initial operation. We utilized confocal laser scanning microscopy (CLSM) to detect the presence of alpha-Gal epitopes (IB4) and cell nuclei (DAPI).

Results: alpha-Gal specific IgG was significantly increased 3 months after implantation of bioprostheses compared to preoperative values (p < 0.001) and was significantly higher than alpha-Gal specific IgG levels of the control group (p < 0.05). IgG3 was the major subclass directed against alpha-Gal (p < 0.05, pre- vs. postoperative values). In CLSM analysis we demonstrated that bioprostheses explanted 1 week after implantation contained IB4/DAPI positive cells within the collagen matrix. In contrast, in patients who underwent reoperation after 12 months, porcine tissue showed a complete lack of IB4/DAPI.

Conclusion: Our results indicate that the implantation of bioprostheses elicits a specific humoral immune response against alpha-Gal bearing cells compared to controls within 3 months after cardiac surgery. The complete absence of IB4/DAPI positive structures 12 months after implantation indicates a specific degradation of alpha-Gal bearing cells through previous exposure to the human blood circuit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Animals
  • Antibody Specificity
  • Bioprosthesis*
  • Cattle
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes
  • Heart Valve Prosthesis*
  • Heart Valves / surgery*
  • Humans
  • Immunoglobulin G / biosynthesis*
  • Immunoglobulin G / immunology*
  • Immunohistochemistry
  • Middle Aged
  • Postoperative Period
  • Swine
  • Time Factors
  • alpha-Galactosidase / immunology*


  • Epitopes
  • Immunoglobulin G
  • alpha-Galactosidase