Adenosine Deaminase, Blood

CPT CODE:

USEFUL FOR:

Evaluation of hemolytic anemia of obscure cause
Evaluation of severe combined immunodeficiency syndrome

SPECIMEN REQUIRED:

Draw blood in a yellow-top (ACD) tube(s), and send 4 mL ofACD whole blood refrigerated. (Green-top [heparin] tube is notacceptable.)

TRANSPORT TEMPERATURE:

Refrig\Ambient OK\Frozen NO

CLINICAL INFORMATION:

This reaction appears to be an important mechanism for regulating the quantity of adenosine nucleotides (e.g., ATP) within the red cell. Afew cases have been described of congenital hemolytic anemia withmarkedly elevated (50-70 x normal) adenosine deaminase (AD) activity,associated with reduced concentrations of ATP. This hemolyticdisorder is inherited as an autosomal dominant, in contrast to all othererythrocyte enzymopathies. It is probably due to an abnormality of thegenetic regulatory mechanisms, rather than to a mutation of the enzymestructural gene. In some cases of severe combined immunodeficiencydisease (SCID), there has been an associated deficiency of AD whichcan also be tested for by this assay.

CLINICAL INTERPRETATION:

Hemolytic anemia due to AD excess:  AD 48 IU/g hemoglobin to100 IU/g hemoglobin
SCID AD <0.6 IU/g hemoglobin

REFERENCE VALUES:

0.3-1.5 IU/g Hb