The therapeutic effectiveness of a parenteral corticosteroid regimen in suppressing the immunogenic rejection of corneal grafts in a model experimental system was studied. The regimen used was 3 mg/kg/day intramuscularly. Therapy terminated on the 42nd postgraft day and observations were continued for another 42 to 60 days. The results indicate that systemic steroid therapy effectively suppresses immunogenic rejection of corneal grafts during the period of drug administration. Furthermore, prolonged follow up after terminiation of drug therapy suggested that systemic corticosteroids are capable of inducing a state of tolerance or "graft adaptation" in a high percentage of recipient animals. Despite the many known pharmacologic actions of corticosteroids, the precise mechanism by which they abrogate transplantation immunity remains obscure.
Kern M, Leibowitz HM, Elliott JH. Chemotherapeutic Immunosuppression of the Corneal Graft ReactionIV. Systemic Corticosteroids. Arch Ophthalmol. 1967;78(6):769-773. doi:10.1001/archopht.1967.00980030771015