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Test ID SDEX Hemoglobin S, Screen, Blood

Useful For

Screening for hemoglobin S (sickle cell trait)

Method Name

Hemoglobin S Solubility

Reporting Name

Hemoglobin S, Scrn, B

Specimen Type

Whole Blood EDTA

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: ACD (solution B), heparin

Specimen Volume: 1 mL

Additional Information:

1. Patient's age is required.

2. Include recent transfusion information.

Forms: If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

Oncology Test Request Form (T729) (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)

Benign Hematology Test Request Form (T755) (http://www.mayomedicallaboratories.com/it-mmfiles/benign-hematology-test-request-form.pdf)

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood EDTA Refrigerated 7 days

Clinical Information

Homozygous hemoglobin S (sickle cell disease) is a serious chronic hemolytic anemia most commonly found in those of African or Middle Eastern descent.

 

Hemoglobin S is freely soluble when fully oxygenated; when oxygen is removed, polymerization of the abnormal hemoglobin occurs, forming tactoids that are rigid and deformed cells. This leads to sickling of the cells, hemolysis, and many other complications.

 

Heterozygous hemoglobin S (sickle cell trait) is the most common hemoglobinopathy in the United States. This condition is present in about 8% of African Americans. Usually, hemoglobin S trait exhibits no clinical or hematological effects. A small fraction of people with sickle cell trait have recurrent hematuria.

Reference Values

Negative

Precautions: The procedure does not distinguish hemoglobin S trait from homozygous sickle cell disease nor any of the following combinations: S/C, S/D, S/G, S/E, S/thalassemia, S/O-Arab, S/New York and C-Georgetown trait (Hb C-Harlem).

Cautions

A positive test is presumptive evidence for hemoglobin (Hb) S. However, rare sickling hemoglobins such as Hb C-Harlem (C-Georgetown) and Hb I will also produce a positive result.

 

This test only detects the presence of Hb S. It cannot differentiate sickle cell trait (heterozygous Hb S) from sickle cell disease (homozygous Hb S), or Hb S in combination with other abnormalities (eg, S/C, S/D, S/G, S/E, S/beta-thalassemia, S/O-Arab, S/New York, and C-Georgetown trait).

 

The use of packed RBCs instead of whole blood significantly reduces false negatives due to anemia and false positives due to hypergammaglobulinemia (eg, multiple myeloma).

 

False positives can occur due to large numbers of nucleated RBCs.

 

False negatives can occur due to an insufficient quantity of Hb S due to age (neonates) or transfusion. Hb S concentrations 15% to 20% or less may give a negative result.

Day(s) Performed

Monday through Saturday

Report Available

1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

85660

NY State Approved

Yes