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Recommended methods for an additional red cell enzyme (pyrimidine 5′-nucleotidase) assay and the determination of red cell adenosine-5′-triphosphate, 2,3-diphosphoglycerate and reduced glutathione

1989; Wiley; Volume: 11; Issue: 2 Linguagem: Inglês

10.1111/j.1365-2257.1989.tb00195.x

1365-2257

Shiro Miwa, Lucio Luzzatto, R Rosa, D.E. Paglia, W. Schröter, Antonio De Flora, H Fujii, PG Board, Ernest Beutler,

Acute Lymphoblastic Leukemia research

In 1977 the Red Cell Enzyme Expert Panel of the International Committee for Standardization in Haematology (ICSH) issued recommended methods for red cell enzyme analysis (Beutler et al. 1977).These methods have made it possible to measure red cell enzyme activity with reliable and convenient techniques, and to compare results obtained in different laboratories.After the publication of the ICSH recommended methods, pyrimidine 5'-nucleotidase (P5N) deficiency came to our attention.This enzyme was first described by Valentine et al. (1974) as a cytosolic enzyme in human red cells.Hereditary deficiency results in nonspherocytic haemolytic anaemia.This syndrome is characterized by haemolytic anaemia, pronounced basophilic stippling of red cells, and marked increase in both red cell reduced glutathione (GSH) and pyrimidine-containing nucleotides.To date, more than 40 cases have been reported (Miwa & Fujii 1985).P5N deficiency appears to be one of the more common causes of hereditary nonspherocytic haemolytic anaemia.It may also be important in the aetiology of the anaemia of lead intoxication because lead markedly inhibits P5N activity.Two enzymes involved in glutathione synthesis, y-glutamylcysteine synthetase (GC-S) and glutathione synthetase (GSH-S), were not included in the ICSH recommendations because the assay methods were complicated.GC-S deficiency and GSH-S deficiency both appear to be associated with moderate haemolytic anaemia and a marked decrease of red cell GSH (Beutler 1978) and thus the measurement of red cell GSH levels is useful as a screening procedure in diagnosing these two rare enzyme deficiencies.Diminished GSH stability is also a consistent finding in glucose 6-phosphate dehydrogenase (G6PD) deficiency, although the initial decreased GSH content of red cells is not marked.