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

Abstract

We report a case of primary acquired sideroblastic anemia (PASA) associated with elevated erythrocyte adenosine deaminase (ADA) activity. The patient was an 85-year-old Japanese male. Analysis of the peripheral blood revealed pancytopenia, and the bone marrow findings showed marked ringed sideroblasts and chromosomal deletion (46XY, 11q-). The erythrocyte ADA activity was 17 times higher than that of normal control, the leukocyte ADA activity was within the normal range, and the plasma ADA activity was 2 times higher than the normal mean. The adenine nucleotides in the patient's erythrocytes were within normal range. According to starch gel electrophoresis, ADA isozyme of the patient was ADA 1. Western blotting showed an increased amount of ADA protein in the patient's erythrocytes. Southern blotting revealed no gene amplification or large structural change. Dot blot analysis of the reticulocyte mRNA showed no increase in the amount of ADA mRNA in the patient's reticulocytes compared with those of reticulocyte-rich controls. We considered that the mechanism of elevated ADA activity in this acquired defect was similar to that found in hereditary hemolytic anemia associated with ADA overproduction.

Erythrocyte enzyme activities in myelodysplastic syndromes: Elevated pyruvate kinase activity

“…The molecular analysis of case S.H., with its remarkable elevation of ADA, has already been reported elsewhere [23].…”

“…and case K.K., the expression of M2-type PK was not dem-onstrated, and another mechanism should be considered for the elevated erythrocyte PK activity. As for the elevation of ADA activity, the abnormalities at the translational level was suspected [23,27]. Recently, we have isolated human L-type [ 151 and MZtype PK cDNA(K. Tani et al, in preparation).…”

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

“…The resolved proteins were transferred to nitrocellulose paper [5]. The filter was then incubated with anti-ADA rabbit antibody and peroxidase-conjugated anti-rabbit IgG and was stained [6].…”