Glucose 6-phosphate dehydrogenase (G6PD), quantitative, blood and RBC

Alphabetical Test listing

Glucose 6-phosphate dehydrogenase (G6PD), quantitative, blood and RBC-13506

  
Glucose 6-phosphate dehydrogenase (G6PD), quantitative, blood and RBC
  
13506
  
LAB13506
  
G6P
  
Glucose 6-phosphate dehydrogenase (G6PD), quant, whole blood and RBC
G6PD, quant, blood
G6PD, quantitative, blood and RBC
G6PDH
G6PD
  

Evaluate glucose 6-phosphate dehydrogenase (G6PD) deficiency.

  
EDTA whole blood
  
  
8 mL (4 mL in each of two tubes)
  
RBC: Two 500 ┬ÁL Microtainer - lavender (EDTA)
  

Lavender (EDTA), 4mL

  
Heparin whole blood and EDTA whole blood
ACD whole blood and EDTA whole blood
  

Dk green heparin (Li or Na), no gel and Lavender (EDTA), 4mL

 or  AND

or

Yellow ACD (A or B) and Lavender (EDTA), 4mL

 or  AND

  
4 mL each Heparin and EDTA OR ACD and EDTA
  

Heparin whole blood and one EDTA whole blood

 or  

ACD whole blood and EDTA whole blood

  

RBC:

Refrigerated - 72 hours

G6PD:

Refrigerated - 7 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
  
LabCorp Burlington (001917): R-LC
  
Daily
  
2 - 4 days
  

Kinetic - 340 nm

  

Age

Male

Unit/trillion RBC's

Female

Unit/trillion RBC's

0 - 30 days

119 - 734

260 - 728

31 days - 6 months

4 - 535

59 - 511

7 months - 12 years

58 - 384

112 - 366

13 - 17 years

108 - 368

155 - 399

18 - 30 years

156 - 397

155 - 399

>30 years

127 - 427

127 - 427

 

  

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.
With the most prevalent G6PD variants (G6PD A- and G6PD Mediterranean), hemolysis is induced in children and adults by the sudden destruction of older, more deficient erythrocytes after exposure to drugs having a high redox potential (including the antimalarial drug primaquine and certain sulfa drugs) or to fava beans, selected infections, or metabolic abnormalities. In the neonate with G6PD deficiency, however, decreased bilirubin elimination may play an important role in the development of jaundice.
G6PD deficiency should be suspected in any subject with an episode of nonimmune hemolytic anemia, especially if occurring after drug ingestion, infection, or an episode of diabetic ketoacidosis.
 
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.
These "false-negative" (ie, spuriously normal or high) results are a potential concern because the most severely deficient red cells have already been removed from the circulation via hemolysis.
This problem is usually not important when testing male Caucasians but is a concern in some Caucasian females and blacks of both sexes, especially during the reticulocytosis following acute hemolysis. When a false-negative test is suspected, the best approach is to reëvaluate the patient three months after the hemolytic episode, a time at which the red cell mass will have been repopulated with red cells of all ages.
To prevent future hemolytic episodes, subjects with G6PD deficiency should avoid drugs and chemicals with oxidant potential. A partial list of safe and unsafe drugs is given in following table.
 
Partial List of Drugs and Chemicals in Glucose-6-Phosphate Dehydrogenase Deficiency
**Note: This is a partial list only. 
Source: Beutler E. G6PD deficiency. Blood. 1994 Dec 1; 84(11):3613-3636.
 
Unsafe for Class I, II, and III Variants         Safe for Class II and III Variants
Acetanilid                                                                   Acetaminophen
Dapsone                                                                      Aminopyrine
Furazolidone                                                             Ascorbic acid (except in very high doses)
Methylene blue                                                       Aspirin
Nalidixic acid                                                             Chloramphenicol
Naphthalene (mothballs, henna)                     Chloroquine
Niridazole                                                                   Colchicine
Nitrofurantoin                                                          Diphenhydramine
Phenazopyridine                                                     Isoniazid
Phenylhydrazine                                                      L-Dopa
Primaquine                                                               Menadione
Sulfacetamide                                                          Para-aminobenzoic acid
Sulfamethoxazole (Δ)                                           Phenacetin
Sulfanilamide                                                           Phenytoin
Sulfapyridine                                                            Probenecid
Thiazolesulfone                                                       Procainamide
Toluidine blue                                                          Pyrimethamine
Trinitrotoluene                                                        Quinidine
Uricase (rasburicase, pegloticase)                   Quinine
                                                                                        Streptomycin
                                                                                        Sulfamethoxypyridazine
                                                                                        Sulfisoxazole
                                                                                        Trimethoprim
                                                                                        Tripelennamine 
                                                                                        Vitamin K
  
82955
85041
  
Result 49502-8
  
04/05/2019
  
05/20/2019
  
02/23/2021