Humoral Reactivity of Renal Transplant-Waitlisted Patients to Cells From GGTA1/CMAH/B4GalNT2, and SLA Class I Knockout Pigs.

Published

Journal Article

BACKGROUND:Antipig antibodies are a barrier to clinical xenotransplantation. We evaluated antibody binding of waitlisted renal transplant patients to 3 glycan knockout (KO) pig cells and class I swine leukocyte antigens (SLA). METHODS:Peripheral blood mononuclear cells from SLA identical wild type (WT), α1, 3-galactosyltransferase (GGTA1) KO, GGTA1/ cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) KO, and GGTA1/ CMAH /b1,4 N-acetylgalactosaminyl transferase (B4GalNT2) KO pigs were screened for human antibody binding using flow cytometric crossmatch (FCXM). Sera from 820 patients were screened on GGTA1/CMAH/B4GalNT2 KO cells and a subset with elevated binding was evaluated further. FCXM was performed on SLA intact cells and GGTA1/SLA class I KO cells after depletion with WT pig RBCs to remove cell surface reactive antibodies, but leave SLA antibodies. Lastly, human and pig reactive antibodies were eluted and tested for cross-species binding and reactivity to single-antigen HLA beads. RESULTS:Sequential glycan KO modifications significantly reduce antibody binding of waitlisted patients. Sera exhibiting elevated binding without reduction after depletion with WT RBCs demonstrate reduced binding to SLA class I KO cells. Human IgG, eluted from human and pig peripheral blood mononuclear cells, interacted across species and bound single-antigen HLA beads in common epitope-restricted patterns. CONCLUSIONS:Many waitlisted patients have minimal xenoreactive antibody binding to the triple KO pig, but some HLA antibodies in sensitized patients cross-react with class I SLA. SLA class I is a target for genome editing in xenotransplantation.

Full Text

Duke Authors

Cited Authors

  • Martens, GR; Reyes, LM; Li, P; Butler, JR; Ladowski, JM; Estrada, JL; Sidner, RA; Eckhoff, DE; Tector, M; Tector, AJ

Published Date

  • April 2017

Published In

Volume / Issue

  • 101 / 4

Start / End Page

  • e86 - e92

PubMed ID

  • 28114170

Pubmed Central ID

  • 28114170

Electronic International Standard Serial Number (EISSN)

  • 1534-6080

International Standard Serial Number (ISSN)

  • 0041-1337

Digital Object Identifier (DOI)

  • 10.1097/tp.0000000000001646

Language

  • eng