[Morphological study of renal changes with age: the possibility of kidney donations by the elderly]

Samples from seventy autopsy cases ranging from 27 to 79 years of age who had shown no evidence of renal or malignant diseases were examined histologically to clarify renal changes with age. We evaluated scores for renal histological change and referred the scores to clinical laboratory data; blood pressure, complete blood counts (RBC count, hematocrit, hemoglobin), serum chemistry values (creatinine, urea nitrogen, total cholesterol, total protein, sodium, potassium, chloride) and urinalysis (protein, sediment). We found the score to be related to serum creatinine level, blood urea nitrogen level and the degree of hematuria but not related to the other factors. The progression of arteriosclerosis, tubulo-interstitial change and global sclerosis were found to be severe with ageing. Also renal weight decreased with increasing age. However there were great differences among individuals in the extent of changes. We could not assume histological changes were generally severe in those of more than 55-65 years of age. It was impossible to clarify renal states only with clinical findings. Some kidneys had severe histological changes though less than 2.0 mg/dl of serum creatinine level. It suggests that living relatives and cadavers over 60 years old can be donors for renal transplantation when there are no significant findings of abnormality in preoperative evaluations of their physical state. If insufficient examinations are done, we cannot determine which of them will be good donors. Therefore preoperative biopsy is the best way to evaluate donor suitability. To evaluate only clinical data, it is necessary that serum creatinine level be less than 1.2 mg/dl, blood urea nitrogen level be less than 23 mg/dl and there be no hematuria.