Among major histocompatibility complex (MHC) mismatched dogs, bone allografts of the vascularized tibia with short-term immunosuppression drugs were done.
This preliminary study was divided into three groups using twelve dogs as follows:
1. Allograft with Cyclosporin (CyA) in three pairs.
2. Allograft with FK506 (FK) in three.
3. Autograft without immunosuppression in one dog served as a control.
Radiological evaluations after operation were analyzed by plane X-ray, angiogram and bone scintigram.
Allograft with CyA had union at about three months as early as autograft, but allograft with FK did not have nonunion yet. Because two of three dogs given high dose of FK506 (1.0mg/kg/day) died approximately three weeks after transplantation and another dog under low dose of FK506 (0.32mg/kg/day) showed rejection by Tc-P bone scintigram. The graft rejected showed no callus formation in the plane radiogram. Bone scintigram indirected the definit process of rejection, differentiating between vascular thrombosis of the anastomosed vessel and rejection.