The importance of eosinophil cells in kidney allograft rejection.

The composition of the intragraft cellular infiltrate was studied in 83 renal allograft recipients with the technique of fine-needle aspiration cytology in the first four weeks following kidney transplantation. We found a significantly (P less than 0.05) higher mean tissue eosinophil percentage in patients who had irreversible rejections with transplant loss than in those who had reversible rejections (12.54 +/- 2.31 versus 3.79 +/- 1.14, mean +/- SEM). Patients who had serious, dialysis-requiring rejections also showed a significantly (P less than 0.05) higher mean tissue eosinophil percentage than those who had reversible rejections (21.40 +/- 5.98 versus 3.79 +/- 1.14, mean +/- SEM). The frequency of the HLA B8 antigen was 46.2% in patients who had excessive tissue eosinophilia, whereas its frequency in all the studied patients was 18.3%. Based on our observations, the presence of more than 4% eosinophils in the tissue inflammatory exudate is a specific (91%) and fairly sensitive (78%) indicator of irreversible and severe acute rejections.