G6PD Enzyme Activity Test in Arizona

What this test measures

Glucose 6-phosphate dehydrogenase is an enzyme in the red blood cell pathway that regenerates molecules needed to neutralize oxidative damage. When activity is low, red blood cells are more vulnerable to stresses such as infection, certain foods, or some medications, and they can rupture in a process called hemolysis. The result is reported as a quantitative activity level rather than a simple positive or negative.

A blood sample is drawn from a vein, and the laboratory measures enzyme activity in the red cells. Because a recent episode of hemolysis or a recent blood transfusion can distort the result, the ordering provider should be told about any such event. In some situations, testing may be repeated once the blood count has stabilized.

A low activity level supports a diagnosis of G6PD deficiency, but results are always interpreted with the full clinical picture, including hemoglobin, bilirubin, and evidence of red cell breakdown. A qualified healthcare provider determines what the value means for an individual and whether additional testing is needed.