Glucose 6 phosphate dehydrogenase
(G6PD)

Sample type:

whole blood (EDITA tube) or(heparin tube)

uses:

we use this test to diagnosis hereditary hemolytic anemia Because of a genetic problem. Due to deficiency in CD55 and CD59.

Precaution:

1) The diagnosis of G6PD deficiency is made by a quantitative spectrophotometric analysis

2) Sampling on EDITA tube

3) Giving the patient the necessary instructions before performing the analysis

4) The diagnosis of G6PD deficiency is made by a quantitative spectrophotometric analysis

Interfering factors:

1) Marked reticulocytosis may give a falsely high G6PD.

2) G6PD may be falsely normal for 6 to 8 weeks after a hemolytic episode, especially in black persons with the type A variant. Retest after the patient recovers from the episode of anemia.

3) Drugs that cause hemolysis in G6PDdeficient persons inflict oxidative damage to erythrocytes leading to erythrocyte destruction. Hemolysis typically occurs 24 to 72 hours after ingestion, with resolution within four to seven days. Oxidative drugs ingested by a woman who is breastfeeding may be transmitted in breast milk and can cause acute hemolysis in a G6PDdeficient child.

Pre analytical errors:

1) In patients with acute hemolysis, testing for G6PD deficiency may be falsely negative because older erythrocytes with a higher enzyme deficiency have been hemolyzed.

2) Patient eating fava beans

3) The clotting of blood after collection or during collection is found to be major cause of rejection of blood sample.

Corrective action:

1) Consultation with the patient’s physician, what should we do in this case?

2) Preventing the patient from eating fava beans for two weeks before doing the tests.

3) Fill the EDITA tube by blood at the mark on the tube.

Post analytical error:

Changing the results due to the exchange of patients’ names. Writing false results in report

Corrective action:

Use codes that contain all patient data or write the patient’s name correctly.

Reference range:

Adults: 8.6–18.6 U/g Hb or 0.14–0.31 nkat/g Hb

Children: 6.4–15.6 U/g Hb or 0.11–0.26 nkat/g Hb