Intragraft CD45 RO gene expression is an early marker to detect small bowel allograft rejection in rats

Wistar Furth (WF) intestinal allografts were transplanted into Sprague-Dawley (SD) rats. Recipients were randomly allocated into the following groups: (1) no treatment; (2) cyclosporine (CsA) 6 mg/kg/day, daily, subcutaneously (s.c.; full-dose therapy); (3) CsA 3 mg/kg/day, daily, s.c. (half-dose therapy); and (4) CsA 3 mg/kg/day, daily, s.c. + Tripterygium Wilfordii Hook. WF (TW) 3 mg/kg/day, daily, s.c. WF rats with intestinal autografts were used as controls. CD45RO intragraft expression and its index (CD45RO/CD45), measured by reverse transcription polymerase chain reaction (RT-PCR), were significantly elevated in untreated and half-dose CsA-treated allografts as early as postoperative day (POD) 4, when rejection of intestinal allografts was not detected by routine pathology. Intestinal permeability measured by Tc-DTPA radioassay was significantly elevated in untreated allografts on POD 6. Histology showed that there was severe rejection in untreated intestinal allografts and mild rejection in allografts treated with a half dose of CsA on POD 6. There was a normal CD45RO expression, permeability, and histology in intestinal allografts treated with either a full dose of CsA or a half dose of CsA + TW. These data indicate that CD45RO intragraft gene expression is an early marker to detect intestinal allograft rejection in rats.