Objective   To evaluate dynamic changes of chemokine CXCL9 and chemokine receptor CXCR3 to predict the early acute rejection in rats after renal transplantation.    Methods   Renal allogeneic grafting was performed on Brown Norway or Lewis rats as donors and Lewis rats as recipients. CXCL9 in serum was measured by ELISA and CXCR3 mRNA in peripheral blood lymphocytes by RT-PCR at the time points of just before and 1

3

5

and 7 d after operation. Serum creatinine (Cr) was measured simultaneously.    Results   The serum contents of CXCL9 and Cr

and CXCR3 mRNA level in allograft group were significantly higher than those in isograft group (P0.01). There was no significant difference on CXCL9 content and CXCR3 mRNA level in both allograft and isograft groups before operation

and the difference become significantly higher on the day 1

3

5 and 7 after operation in allograft group than that in isograft group (P0.05). No difference was seen on the serum Cr level in allograft and isograft groups before and 1 d after operation

but the difference was observed on 3

5 and 7 d after operation between the 2 groups (P0.05).    Conclusion   Serum CXCL9 content and CXCR3 mRNA level in peripheral blood lymphocytes are sensitive predictors for the early diagnosis of acute rejection.