The role of apoptosis in acute kidney transplantation rejection (clinicopathologic study).

초록

Apoptosis is an active form of cell death and mediates the deletionof unwanted cells with little inflammation and tissue injury. The influence of apoptosis and abnormalities of this process on various renal disease, including renal inflammation and autoimmunity to renal tissue, are nowbeing investigated; however, the relationship of rejection after kidneytransplantation (KT) and apoptosis is unknown. To evaluate the degree of apoptosis and the relationship with the clinical parameters in acutetransplant rejection, in situ end labelling (ISEL) technique was used toidentify the apoptotic process in kidney tissues which was pathologicallyconfirmed as acute rejection. For quantitation of apoptotic cell number, 200 randomly selected tubular epithelial cells were counted. We definedthe high group if the percentage of apoptotic cells was more than 23%(N = 7) and the low group if that was less than 25% (N = 5). The relationships of apoptosis and clinical data, including the degree of HLAmismatching, underlying disease, mean serum cylosporine level, and peak creatinine level, were also analyzed. The results were as follows: (1) The mean age and male:female ratio of the patients were 39.4 (range 19—65) and 7:5, respectively. (2) Seven of 12 patients showed high staining pattern and 5 of them were low staining pattern. The mean percentage of apoptotic cells was 33.75 24.23%. (3) In the high group, there was significant increase in the mean serum cyclosporine A level and lower prednisolone dose (cyclosporine A level: 320.96 147.49 ng!ml vs. 176.70 51.33 ng/ml, p = 0.027; prednisolone dose: 2.112 0.706 vs. 3.015 0.831 mg/kg/day, P = 0.074 in the high and low groups, respectively). (4) There were no significant differences between the 2groups in age, sex, degree of HLA mismatching, ischemic time, peak BUNand creatinine concentration. These results suggest that apoptosis mayoccur in acute transplant rejection and the apoptotic rate seems to be related to serum cyclosporine A level, but further studies are required toreveal the role of apoptosis in kidney transplantation rejection.