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HelpTest ID RBCME Red Blood Cell Membrane Evaluation, Blood
Useful For
Investigation of suspected red cell membrane disorder such as hereditary spherocytosis or hereditary pyropoikilocytosis
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| FRAGO | Osmotic Fragility | No, (Order FRAG) | Yes |
| SCTRL | Shipping Control Vial | No | Yes |
| HSEV | Spherocytosis Interpretation | No | Yes |
| BND3 | Band 3 Fluorescence Staining, RBC | No | Yes |
| SMPB | Peripheral Blood Smear Review | No | Yes |
Testing Algorithm
A consultative interpretation will be provided.
Special Instructions
Method Name
HSEV: Consultative Interpretation
FRAGO: Osmotic Lysis
BND3: Flow Cytometry
SMPB: Consultant Review
Reporting Name
RBC Membrane Evaluation, BSpecimen Type
ControlWhole Blood EDTA
Whole Blood Slide
Specimens must arrive within 72 hours of draw.
A whole blood EDTA specimen, an EDTA control specimen, and 2 well-made peripheral blood smears (Wright stained or fixed in absolute methanol) are required for testing.
Forms:
1. Red Cell Membrane Disorders Information Sheet (Supply T706) is available in Special Instruction.
2. If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/benign-hematology-test-request-form.pdf)
Patient:
Specimen Type: Blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 4 mL
Collection Instructions:
1. Immediately refrigerate specimen after draw. Refrigerate at 0 to 4° C. Do not freeze. Freezing causes sample lysis, and tests will not be performed on hemolyzed specimens.
2. Send specimen in original tube. Do not aliquot.
3. Rubber band patient specimen and control vial together. Control must accompany the patient sample at all times to ensure the reliability of testing results.
4. Be sure specimen and control are stored and transported together at refrigerate temperature, carefully following proper handling and shipping instructions.
Additional Information: Patient's age and sex are required.
Patient:
Specimen Type: Slides
Container/Tube: Blood smears
Specimen Volume: 2 well-made peripheral blood smears
Collection Instructions: Collect 2 well-made peripheral blood smears (Wright stained or fixed in absolute methanol).
Additional Information: Patient's age and sex are required.
Normal Shipping Control:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 4 mL
Collection Instructions:
1. Draw a control specimen from a normal (healthy), unrelated, nonsmoking person at the same time as the patient.
2. Label clearly on outermost label normal control.
3. Immediately refrigerate specimen after draw. Refrigerate at 0 to 4° C. Do not freeze. Freezing causes sample lysis, and tests will not be performed on hemolyzed specimens.
4. Send specimen in original tube. Do not aliquot.
5. Rubber band patient specimen and control vial together. Control must accompany the patient sample at all times to ensure the reliability of testing results.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Control | Refrigerated | 72 hours |
| Whole Blood EDTA | Refrigerated | 72 hours |
| Whole Blood Slide | Refrigerated | |
Clinical Information
The hemolytic anemias are a group of anemias that are characterized by an increased destruction of RBCs. Anemias may be divided into inherited or acquired. Hereditary spherocytosis (HS) is inherited as a non-sex-linked dominant trait. HS is caused by a RBC membrane defect. The RBCs are spherocytic in shape and show an increased rate of destruction. HS can result from abnormalities involving several red cell membrane proteins, such as band 3, spectrin, and ankyrin.
Most often HS is diagnosed in childhood, adolescence, or early adult life. The diagnosis of HS is usually made by a combination of patient and family history, laboratory evidence of hemolysis, and review of a peripheral blood smear. The osmotic fragility test is usually markedly abnormal in these cases. However, factors such as age, sex, and medications can affect the osmotic fragility test.
This evaluation combines osmotic fragility testing with a flow cytometry assay to provide complementary information in the evaluation of patients with suspected HS.
Reference Values
≥12 months:
0.50 g/dL NaCl (unincubated): 3-53 % hemolysis
0.60 g/dL NaCl (incubated): 14-74 % hemolysis
0.65 g/dL NaCl (incubated): 4-40 % hemolysis
0.75 g/dL NaCl (incubated): 1-11 % hemolysis
An interpretive report will be provided.
Reference values have not been established for patients who are <12 months of age.
Cautions
This test is not very useful for hereditary elliptocytosis.
Interfering factors:
-Recent transfusion
-Oral contraceptives
-H2 blockers
Infrequently, other hemolytic disorders may also be associated with positive results, as in patients with congenital nonspherocytic hemolytic anemia due to glucose-6-phosphate dehydrogenase or pyruvate kinase deficiency.
Patients with an immunohemolytic anemia, or who have recently received a blood transfusion may also have increased RBC lysis.
The shipping control specimen is required to adequately interpret these cases, as temperature extremes can increase fragility of the specimen.
Resulting Cautions:
Osmotic fragility results will be reported if the shipping control is normal.
If the shipping control is abnormal and the osmotic fragility results are within normal range, the results will be reported; however, a comment will be added to the report indicating that the shipping control was not entirely satisfactory.
The test will be cancelled if the patient specimen and shipping control are both abnormal.
Day(s) Performed
Monday through Saturday
Report Available
4 days (not reported on Saturday or Sunday)Performing Laboratory
Mayo Medical Laboratories in Rochester
CPT Code Information
85557-Osmotic fragility
88184-Flow cytometry; first cell surface, cytoplasmic or nuclear marker x 1
85060-Morphology review