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Test Code UNHB Unstable Hemoglobin, Blood

Performing Laboratory

Mayo Medical Laboratories in Rochester

Reporting Name

Unstable Hemoglobin, B

Specimen Type

Whole Blood EDTA


Specimen Required


Only orderable as part of a profile or as a reflex. For more information see HAEVP / Hemolytic Anemia Evaluation; or HBELC / Hemoglobin Electrophoresis Cascade, Blood; or THEVP / Thalassemia and Hemoglobinopathy Evaluation; or REVE / Erthrocytosis Evaluation; or MEVP / Methemoglobinemia Evaluation.


Specimen Stability Information

Specimen Type Temperature Time
Whole Blood EDTA Refrigerated 7 days

Specimen Minimum Volume

1 mL

Reference Values

Only orderable as part of a profile or as a reflex. For more information see HAEVP / Hemolytic Anemia Evaluation; or HBELC / Hemoglobin Electrophoresis Cascade, Blood; or THEVP / Thalassemia and Hemoglobinopathy Evaluation; or REVE / Erthrocytosis Evaluation; or MEVP / Methemoglobinemia Evaluation.

 

Normal (reported as normal [stable] or abnormal [unstable])

Useful For

Work-up of congenital hemolytic anemias

Method Name

Only orderable as part of a profile or as a reflex. For more information see HAEVP / Hemolytic Anemia Evaluation; or HBELC / Hemoglobin Electrophoresis Cascade, Blood; or THEVP / Thalassemia and Hemoglobinopathy Evaluation; or REVE / Erthrocytosis Evaluation; or MEVP / Methemoglobinemia Evaluation.

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

83068

LOINC Code Information

Test ID Test Order Name Order LOINC Value
UNHB Unstable Hemoglobin, B In Process

 

Result ID Test Result Name Result LOINC Value
9095 Hemoglobin, Unstable, B 4639-1

Clinical Information

Unstable hemoglobin disease is rare and may be caused by any 1 of a large number of hemoglobin variants. They are inherited as an autosomal dominant trait. The severity of the disease varies according to the hemoglobin variant; there may be no clinical symptoms or the disease may produce a mild, moderate, or severe hemolytic anemia.

 

The stained peripheral blood smear shows anisocytosis, poikilocytosis, basophilic stippling, polychromasia and, sometimes, hypochromia. The reticulocyte count may be increased. Splenomegaly and Heinz bodies may also be present.

Interpretation

An abnormal or unstable result is indicative of a hemoglobin variant present. Other confirmatory tests should be performed to identify the hemoglobinopathy (HBELC / Hemoglobin Electrophoresis Cascade, Blood).

Cautions

False positives will be obtained in blood specimens containing >5% fetal hemoglobin or in specimens >1 week old.

Clinical Reference

Hoyer JD, Hoffman DR: The thalassemia and hemoglobinopathy syndromes. In Clinical Laboratory Medicine. Second edition. Edited by KD McMlatchey. Philadelphia, Lippincott Williams and Wilkins, 2002, pp 866-895

Method Description

Unstable hemoglobins precipitate in dilute solutions of isopropanol. Washed erythrocytes are hemolyzed and cleared by centrifugation. Isopropanol is added. The hemolysate is incubated at 37° C for 20 minutes and examined for turbidity. There is no turbidity with normal hemoglobins.(Schmidt RM: Laboratory diagnosis of hemoglobinopathies. In Hematology Clinical and Laboratory Practice. Edited by RL Bick. St. Louis, Mosby-Year Book Inc, 1993, pp 327-389)