Background: We aimed to investigate (a) the long-term survival of corneal grafts from α1,3-galactosyltransferase gene-knockout miniature (GTKOm) pigs in non-human primates as a primary outcome and (b) the effect of anti-CD20 antibody on the survival of corneal grafts from GTKOm pigs as a secondary outcome. Methods: Nine rhesus macaques undergoing full-thickness corneal xenotransplantation using GTKOm pigs were systemically administered steroid, basiliximab, intravenous immunoglobulin, and tacrolimus with (CD20 group) or without (control group) anti-CD20 antibody. Results: Graft survival was significantly longer (P =.008) in the CD20 group (>375, >187, >187, >83 days) than control group (165, 91, 72, 55, 37 days). When we compared the graft survival time between older (>7- month-old) and younger (≤7-month-old) aged donor recipients, there was no significant difference. Activated B cells were lower in the CD20 group than control group (P =.026). Aqueous humor complement C3a was increased in the control group at last examination (P =.043) and was higher than that in the CD20 group (P =.014). Anti-αGal IgG/M levels were unchanged in both groups. At last examination, anti-non-Gal IgG was increased in the control group alone (P =.013). Conclusions: The GTKOm pig corneal graft achieved long-term survival when combined with anti-CD20 antibody treatment. Inhibition of activated B cells and complement is imperative even when using GTKO pig corneas.
- anti-CD20 antibody
- non-human primate
- α1,3-galactosyltransferase gene-knockout miniature (GTKOm) pig