In a patient with
hyperargininemia,
enzyme replacement therapy such as
whole blood exchange transfusion or
erythrocyte transfusion was performed, and its effect was confirmed in vitro as well as in vivo. The patient has been treated with the restriction of
protein intake,
oral administration of an
essential amino acid mixture, and
sodium benzoate or
phenylacetic acid. With these treatments, his plasma
ammonia levels were controlled. On the other hand, plasma and CSF concentrations of
arginine were not so well controlled. With
whole blood exchange transfusion and
erythrocyte transfusion, plasma
arginine concentrations and plasma
ammonia levels were controlled. These effects have continued for about 3 months. Furthermore, the effect of exchanged erythrocytes on the blood
arginine levels was also confirmed by in vitro experimentation that mixes
arginine with erythrocytes in the medium RPMI 1640.
Arginine concentration of the medium did not decrease when
arginine was mixed with erythrocytes of the patient, but when
arginine was mixed with erythrocytes of mother or normal controls, it decreased rapidly. In calculation, 10(7) of erythrocytes of the mother or normal controls was presumed to metabolize 4-5 nmole of
arginine per day. From these results, the erythrocyte exchange transfusion is considered to be effective for the control of clinical and biochemical abnormalities in this disorder.