Glucose 6-Phosphate Dehydrogenase (G-6-PD)
G6PD, Quantitative, Blood and RBC
Evaluate glucose 6-phosphate dehydrogenase (G6PD) deficiency.G6PD deficiency, an X-linked disorder, is the most common enzymatic disorder of red blood cells in humans, affecting more than 400 million people worldwide. The clinical expression of G6PD variants encompasses a spectrum of hemolytic syndromes. Affected patients are most often asymptomatic, but many patients have episodic anemia, while a few have chronic hemolysis.
G6PD hemolysis is associated with formation of Heinz bodies in peripheral red blood cells. It is the older erythrocytes that are most G6PD-deficient in affected individuals. These cells are first eliminated in a hemolytic crisis. The younger cells and reticulocytes contain more G6PD. For these reasons, after a hemolytic crisis, when only younger erythrocytes and reticulocytes are present, the G6PD values may be spuriously normal.
8 mL (4 mL in each of two tubes)
Minimum Volume RBC: Two 500-μL lavender-top Microtainer™ tubes filled to at least 50% of tube capacity. (Note: If any other size lavender tube is used, the tube must be filled to at least 50% capacity of tube fill volume. Insufficient volume may limit the extent of procedures performed.) and G6PD: One lavender-top (EDTA) tube, green-top (heparin) tube, or yellow-top (ACD) tube (0.1 mL) whole blood.
Two lavender-top (EDTA) tubes; or one green-top (heparin) tube and one lavender-top (EDTA) tube; or one yellow-top (ACD) tube and one lavender-top (EDTA) tube
RBC: Stable refrigerated for 72 hours. G6PD: stable refrigerated for seven days.
RBC: Hemolysis; tube not filled with minimum fill volume; specimen drawn in any anticoagulant other than EDTA; specimens diluted or contaminated with IV fluid; clotted specimen; improper labeling; transfer tubes with whole blood; lavender-top (EDTA) tubes received with plasma removed; samples more than 72 hours old. G6PD: Frozen specimen; clotted specimen.