Deficiency of pyrimidine 5′‐nucleotidase in human leukocytes

Abstract

Both erythrocytes and leukocytes from a patient with erythrocyte pyrimidine 5'-nucleotidase (P5N) deficiency were shown to contain increased amounts of pyrimidine nucleotides. These findings suggested that the leukocytes were also deficient for P5N. Measurement of the P5N activity in lysates from lymphocytes or granulocytes, in the presence of inhibitors for non-specific 5'-nucleotidase or alkaline phosphatase, indeed showed a deficiency for P5N in lymphocytes and granulocytes of the patient with erythrocyte P5N deficiency. However, the P5N deficiency in the leukocytes did not cause clinical disturbances in addition to the weak haemolytic anaemia.

Nucleotide Degradation

“…In the developing erythrocyte, UMPH-1 hydrolyses nucleotides to the corresponding nucleosides, that can be transported to other tissues for recycling. The defect results in substantial accumulation of cytidine and uridine nucleotides, which can be demonstrated in lymphocytes, granulocytes (De Korte et al, 1989) and erythrocytes. However, the defect is seemingly only harmful to erythrocytes, resulting in nonspherocytic haemolytic anaemia with prominent basophilic stippling.…”