Elevated red cell adenosine deaminase activity: a marker of disordered erythropoiesis in Diamond-Blackfan anaemia and other haematologic diseases.
Red-cell adenosine deaminase (ADA) activity in children with Diamond-Blackfan anaemia is significantly increased (1.91 +/- 0.90 U/g Hb) compared to that seen in transient erythroblastopenia of childhood (0.80 +/- 0.16 U/g Hb) or normal individuals (0.61 +/- 0.13 U/g). These data thus further support that measurement of this purine metabolic enzyme is useful in diagnosing the cause of pure RBC aplasia in children. Of interest, however, elevated RBC-ADA activity also is seen in some children with acute leukaemia and other haematologic disorders. In children with acute lymphoblastic leukaemia (ALL), the increase in RBC-ADA activity is proportional to the degree of anaemia. However, the elevated RBC-ADA activity in this leukaemic population is not related to the fetal haemoglobin concentration. These data suggest increased RBC-ADA activity may be a non-specific manifestation of abnormal erythroid stem cell function, an alteration distinct from that seen with reactivation of fetal erythropoiesis. However, since almost all patients with Diamond-Blackfan anaemia manifest elevated RBC-ADA activity, this chemical alteration yet may reflect the specific erythroid differentiation lesion in this disorder.
Glader
B E
BE
Department of Pediatrics, Stanford University School of Medicine, California.
Backer
K
K
D000208:Acute Disease; D000243:Adenosine Deaminase / Q000378:metabolism*; D000741:Anemia, Aplastic / Q000201:enzymology*; D002648:Child; D004912:Erythrocytes / Q000201:enzymology*; D004913:Erythrocytes, Abnormal; D004920:Erythropoiesis; D006402:Hematologic Diseases / Q000201:enzymology*; D006801:Humans; D007938:Leukemia / Q000201:enzymology; D009700:Nucleoside Deaminases / Q000378:metabolism*
D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase