Elevated erythrocyte adenosine deaminase activity in a patient with primary acquired sideroblastic anemia

Erythrocyte enzyme activities in myelodysplastic syndromes: elevated pyruvate kinase activity

The erythrocyte enzyme activities in twenty-six cases of myelodysplastic syndromes were determined. There were remarkably abnormal levels in seven cases; namely, four cases showed increased hexokinase activity, three cases showed increased pyruvate kinase activity, and two cases showed increased adenosine deaminase activity. Among these, one case with elevated pyruvate kinase activity showed the novel expression of M2-type pyruvate kinase activity, in addition to the R-type pyruvate kinase activity normally found in erythrocytes. Southern blotting of peripheral leucocyte DNA revealed only an amplified PK-LR genome, which derived from the chromosomal abnormality of a 1;7 translocation. The mechanism responsible for switching M2-type to R-type during erythroid maturation was considered to be partially disrupted in this case.

Genetic analysis of adenosine deaminase expression in adult T-cell leukemia

We investigated the genetic basis for the increased adenosine deaminase (ADA) expression in adult T-cell leukemia (ATL). We found a correlation between the levels of ADA-specific mRNA and ADA immunoreactive protein in ATL. Southern blot analysis revealed no gene amplification or rearrangement of the ADA gene. These findings indicate that increased ADA expression in ATL cells reflects increased transcriptional activity for the ADA gene or increased stability of ADA mRNA.