97th DOG Annual Meeting 1999

V557

THE EFFECT OF CORTICOSTEROID AND CYCLOSPORIN A ON MURINE CORNEAL ALLOGRAFT REJECTION

F. Hoffmann, E.-P. Zhang

Our aim was to compare the corticosteroid and Cyclosporin A (Cy A) effect on corneal allograft survival and possibly to induce tolerance.

Methods: Female BALB/c mice received corneal buttons from minor and major MHC antigen different C3H mice. The animals were divided into the following groups (n=6): (1) untreated; (2) intramuscular (i.m.) injection of Cy A daily at a total dose of 11 mg in 2 weeks; (3) corticosteroid treatment for 40 days: 1 mg dexamethasone i.m. from the day of operation until day 4, dexamethasone eye drops 5 times daily from day 5 to 9, 3 times daily from day 10 to 19, twice daily from day 20 to 29, once daily from day 30 to 39; (4) combined treatment of group 2 and 3; (5) corticosteroid treatment for 90 days as follows: glucocorticoid ointment from the day of operation until day 4, dexamethasone eye drops 5 times daily from day 5 to 9, 3 times daily from day 10 to 19, twice daily from day 20 to 59 and then once daily. Following surgery the assessment of the graft opacity was performed by slit lamp microscopy using a score of 0-5 point.

Results: All grafts were clear on the second postoperative day. The allograft reaction occurred in group (1) on day 13,6 ± 1,63 (mean ± S); in group (2) on day 15,3 ± 1,5; in group (3) on day 48 ± 6,57; in group (4) on day 56,16 ± 17,6; in group (5) on day 88,7 ± 2,9. Cy A had no significant effect on graft survival. Corticosteroid treatment (3) significantly prolonged allograft survival (p < 0,01). The higher dose of corticosteroid treatment (5) had a significant larger effect in comparison to group 3 (p < 0,01).

Conclusion: Our results indicate that the corticosteroid treatment very effectively suppresses the immune response in a dose dependent manner. However, tolerance could not be achieved in this animal model by dexamethasone. Cy A had no significant effect on allograft survival.

Augenklinik, Universitaetsklinikum Benjamin Franklin, Hindenburgdamm 30 D - 12200 Berlin

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