STUDIES ON LEUCINE AMINOPEPTIDASE (LAP) IN UROLOGICAL DISEASES

REPORT II. EARLY DIAGNOSIS OF REJECTION REACTIONS

Abstract

To date the rejection crises of renal homografts have been detected mainly by the clinical signs of patients after renal homotransplantation. As the author has reported in the previous paper, it is possible to detect rejection reactions of the homografts by the measurement of urinary LAP activities. Further studies have been made on urines of patients after renal transplantation in order to establish the classification of the rejection stages, rejection reactions, and standardization for urinary LAP values as well as to obtain a measure for the prognosis. From the results obtained through the observations for about 21 months in the 9 cases of renal homotransplantation performed and followed at the Tokyo University Hospital, the following conclusions were obtained:
1) The enzymatic rejection reaction occurs 5 days to 2 weeks prior to the clinical rejection reaction. 2) The initial rejection reaction will occur within 2 weeks after the renal homotransplantation. 3) The rejection reaction will last for a week to a month. 4) The temporary increase of urinary LAP activities observed in the first day of homotransplantation does not mean the rejection reaction. 5) No interrelationship between leucocytosis and increasing values of urinary LAP activities was observed. The leucocytosis within one week to two weeks after the renal homotransplantation is unworthy for detecting the initial rejection reaction. 6) The measurement of the urinary LAP activities will give a standard pattern for the administration of immunosuppressive drugs. 7) The prognosis of the cases with enzymatic rejection reaction is good because the clinical symptoms in these cases are mild. 8) The prognosis of cases with chronic rejection reaction is generally unfavorable and when the chronic rejection reaction moves to the refusal type, the prognosis promptly becomes grave. 9) The sudden decrease of urinary LAP activity in the steady stage means the developement of complications. When the urinary LAP activity fails to return to the level of the steady stage, or when the rejection reaction moves to the refusal type, the death is considered to be imminent. 10) When the rejection reaction moves to the critical stage without passing the steady stage and indicate the pattern of the sudden decrease of LAP activity, a direct death caused by the rejection reaction will be observed.