Studies on the Pseudouridinuria of Chronic Lymphocytic Leukemia

This paper reports a group of investigations attempting to explain the elevated pseudouridine excretion in the presence of normal uric acid excretion which occurs in chronic lymphocytic leukemia (CLL). Studies with isotopically labeled uric acid and adenine indicated that diversion of body purines from uric acid does not occur. Similarly the chemical analysis of the white cells in CLL did not reveal any excess content of pyrimidines, nor did the turnover of the ribonucleotides show any selective retention of purines as compared with pyrimidines. Studies with isotopically labeled orotic acid, however, indicated on overproduction of other pyrimidines as well as pseudouridine. Though no explanation has yet been found for the selective pyrimidine overproduction seen in CLL, a major portion of these pyrimidines appear to be derived from rapidly renewing sources.