Influence of cyclophosphamide on homograft rejection

Abstract

A histological study of ear-skin homografts exchanged between dissimilar strains of rabbits was carried out, comparing the rejection response between animals receiving 25 mg/kg/day of cyclophosphamide and those which received no drug. The animals were killed at staged intervals after operation while their grafts were still viable. The histological sequence of events was found to be: great dilatation of small blood vessels, formation of cellular thrombi, perivascular cuffing, and infiltration and destruction of epidermal appendages by mononuclear cells. The epidermis proper was the last to be invaded. In the control animals rejection took place swiftly, and the basic mononuclear cell infiltrate was obscured by large numbers of heterophiles responding to necrosis of graft tissue. In the drug-treated animals rejection was slowed, the swift purulent response did not appear, the mononuclear cell response was more leisurely, and its significance more clearly apparent.