Preliminary finding in corneal allograft rejection in patient with keratoconu

Purpoe Claically , corneal allograft rejection i thought to be a TH1-mediated phenomenon. However, TH2-mediated allograft rejection ha been reported in other tranplanted organ ytem, including the heart and kidney. We previouly reported a form of TH2-mediated corneal allograft rejection in a murine model with a TH2 immune bia. In thi tudy we ought to determine if there wa any evidence for thi form of corneal allograft rejection in human. Deign Experimental tudy with an interventional cae erie. Method The clinical record of all keratoconu patient undergoing penetrating keratoplaty at the Univerity of Texa, outhwetern Medical Center from 1994 to 1999 were reviewed. Careful attention wa paid to a clinical hitory of atopy. Atopic patient were elected, becaue thee patient have been hown to have a “TH2 immune bia.” The corneal graft rejection rate in thee patient and the number of repeat corneal tranplant performed wa determined. The experimental group conited of patient with a clinical hitory of atopy and keratoconu who had at leat one repeat penetrating keratoplaty for an immunologically rejected corneal tranplant. Any patient with evidence of primary allograft failure wa excluded from thi tudy. Tiue pecimen from thee patient were embedded in paraffin, erially ectioned, tained with Giema tain, and examined hitologically. The control group conited of patient without a clinical hitory of allergy (and therefore no TH2 immune bia) who underwent corneal tranplantation for Fuch corneal endothelial dytrophy, or aphakic/peudophakic bullou keratopathy. Failed graft from thee control patient were alo paraffin embedded, erially ectioned, tained, and examined hitologically. The human experimental and control corneal pecimen were compared with data obtained in a murine model of TH2-mediated corneal allograft rejection. Briefly, full-thickne penetrating C57BL/6ByJ corneal allograft were tranplanted onto Balb/cByJ and Balb/c-IFN-γtm1T (Balb/c-IFN-γ knockout) mice. Additionally, full-thickne Balb/cByJ corneal allograft were tranplanted onto C57BL/6ByJ and C57BL/6ByJ-IFN-γtm1T mice. Corneal allograft rejection rate and mean rejection time were calculated and compared between wild-type and interferon gamma (IFN-γ) knockout hot. The rejected allograft were examined hitologically by the ame method ued in the human tiue. Reult There were 84 penetrating keratoplatie performed from 1994 to 1999 for keratoconu. even of thee 84 patient rejected their corneal graft. Of the 7 patient who rejected their corneal allograft, 4 had repeat penetrating keratoplaty. Of thee 4 repeat corneal allograft, 3 howed eoinophilia when compared with rejected graft in control patient. Atopic keratoconu patient had a mixed inflammatory cellular infiltrate in the rejected corneal tiue pecimen with a ignificantly greater denity of eoinophil (P = .001) compared with patient who did not have a pre-exiting TH2 bia. The inflammatory infiltrate in thee patient without a TH2 immune bia wa mononuclear. In the murine model, corneal allograft rejection did occur in the abence of IFN-γ, a critical TH1 cytokine in both fully allogeneic donor–hot combination. Hitologically, rejection in thee (“TH2 mice”) wa characterized by a predominant eoinophilic infiltrate in the rejected graft bed when compared with wild-type animal (“TH1 mice”) that had a predominately mononuclear infiltrate in the rejected corneal graft bed. Concluion Preliminary finding how that corneal allograft rejection in patient with a pre-exiting TH2 phenotype i imilar to what i een in the murine model of TH2-mediated corneal allograft rejection. Baed on thi mall ample, it appear that eoinophil may play a role in corneal allograft rejection in thi group of patient. However, further tudy i neceary to determine the importance of thee cell in allograft rejection.