[Experimental study on usefulness of fine-needle aspiration cytology as a diagnostic tool of acute rejection]

The value of fine-needle aspiration cytology (FNAC) for the diagnosis of acute rejection in canine allotransplantation was determined. To reduce the surgical stress associated with repeated anesthesia and operations, the contra-lateral kidney was left intact. FANC, open biopsy and peripheral blood sampling were performed on day 0, 3, 5, postoperatively. Cytocentrifuged cell smear was prepared from each FNAC specimen, and stained with Giemsa. Specimen on day 3 had an increased number of mono-nuclear cells mainly composed of monocytes, and plasmacytes appeared, but they were not clearly identified. To exclude the contamination of peripheral blood from the specimen, we established an index, increased infiltrate score, to evaluate the percentage gap between the transplanted kidney and the normal own kidney. This score revealed that some kind of mono-nuclear cells increased on day 3, prior to the appearance of plasmacytes which were usually seen on day 5. On the other hand the specimen from the open renal biopsy on day 3 showed little change. We concluded that the FNAC is valuable in the early diagnosis of acute rejection of canine renal allotransplantation.