Evaluation of the clinical and histologic features of renal allograft rejection in cats.
OBJECTIVE
To describe the clinical signs and histopathologic features of renal allograft rejection in cats, and to provide a historical, untreated control group for use in future studies of feline renal allograft rejection.


METHODS
Fourteen adult research cats.


METHODS
Renal transplantation and bilateral nephrectomy were performed in pairs of immunogenically mismatched cats. A physical examination was performed, and packed cell volume, total protein, and plasma creatinine concentrations were measured each day after surgery. The cats were euthanatized when plasma creatinine concentration exceeded 7 mg/dL or when weight loss exceeded 20%. Renal histopathology was scored according to the Banff 97 criteria by 3 pathologists.


RESULTS
Nine cats completed the study. Plasma creatinine exceeded 7 mg/dL in 5 cats, weight loss exceeded 20% in 3 cats, and 1 cat was found dead. Clinical signs in cats with rejection were nonspecific or absent. Rectal temperature decreased by 0.8 +/- 0.5 degrees C in the 24 hours before euthanasia. The pathologists agreed on the allograft histopathologic category in 6 of 9 cats. The histologic consensus was acute/active rejection in 8 cats and normal in 1 cat. Median survival time of the 8 cats with histologically confirmed allograft rejection was 23 days (range, 8-34 days).


CONCLUSIONS
Renal allograft rejection is associated with minimal clinical signs. Therefore, plasma creatinine concentration should be measured routinely in patients with a functioning allograft. An increase in plasma creatinine concentration is highly suspicious for allograft rejection, although a biopsy of the renal allograft is needed for definitive diagnosis.
Kyles
Andrew E
AE
School of Veterinary Medicine, Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA 95616, USA.
Gregory
Clare R
CR
Griffey
Stephen M
SM
Galvez
Jose
J
Ramsamooj
Rajen
R
Morris
Randall E
RE
D000818:Animals; D002371:Cat Diseases / Q000401:mortality* / Q000601:surgery*; D002415:Cats; D003404:Creatinine / Q000097:blood; D006084:Graft Rejection / Q000473:pathology / Q000662:veterinary*; D016030:Kidney Transplantation / Q000401:mortality / Q000662:veterinary*; D016019:Survival Analysis
D003404:Creatinine