Test ID RBCME Red Blood Cell Membrane Evaluation, Blood
Useful For
Investigation of suspected red cell membrane disorders such as hereditary spherocytosis or hereditary pyropoikilocytosis
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
FRAGO | Osmotic Fragility | Yes, (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
Osmotic fragility and eosin-5-maleimide (EMA) binding (Band3) flow cytometry testing will always be performed. A normal shipping control is necessary to exclude false-positive results due to preanalytical artifact. Testing will be canceled if no shipping control is received or if the shipping control is abnormal. A consultative interpretation will be provided.
See Benign Hematology Evaluation Comparison in Special Instructions.
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
Shipping Instructions
Specimens must arrive within 72 hours of draw.
Necessary Information
Include recent transfusion information.
Include most recent CBC results.
Specimen Required
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.
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.
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).
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 | Special Container |
---|---|---|---|
Control | Refrigerated | 72 hours | PURPLE OR PINK TOP/EDTA |
Whole Blood EDTA | Refrigerated | 72 hours | |
Whole Blood Slide | Refrigerated | CARTRIDGE |
Clinical Information
The functional red cell membrane is composed of a cholesterol and phospholipid bilayer anchored by integral proteins to an elastic cytoskeletal network. These interactions form the shape, deformability, and proper ion balance of the cell. Abnormalities in these moieties result in red blood cell membrane disorders.
Hereditary spherocytosis (HS) is a common membrane disorder that can be present in many ethnic groups. Its prevalence has been estimated at approximately 1 in 3,000 persons of Northern European ancestry. It is usually associated with visible spherocytes on the peripheral blood smear and can be associated with variable clinical features of hemolysis ranging from completely compensated to mild to severe.
Hereditary elliptocytosis (HE) is another fairly common and clinically variable disorder that can range from normal RBC indices in the large majority of cases to rare patients with moderate to severe anemia.
Common hereditary elliptocytosis (CHE) is characterized by the presence of elliptocytes on the peripheral blood smear. Mutations associated with HE have been reported in widely variable ethnicities with greater prevalence in populations overlapping the malaria belt.
Hereditary pyropoikilocytosis (HPP) is best classified as a severe form of hereditary elliptocytosis. It is uncommon and presents in early childhood as a severe hemolytic anemia. These disorders are associated with marked poikilocytosis on the peripheral blood smear.(1,2) Red cell membrane disorders can result from abnormalities involving several red cell membrane proteins, such as band 3, alpha and beta spectrin, protein 4.1, protein 4.2, glycophorin C, and ankyrin.
Most often, red cell membrane disorders are 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 (OF) test is usually markedly abnormal in HS cases. However, factors such as age, iron status, and medications can affect the OF test. The OF test is nonspecific and can be increased in acquired disorders such as autoimmune hemolytic anemia. Coombs testing should be negative prior to ordering this test.
The addition of eosin-5-maleimide (EMA) binding (Band3) flow cytometry to this profile increases specificity if a typical moderately decreased pattern is present. Hereditary pyropoikilocytosis can have normal or only mildly increased OF results and often displays a very dim and sometimes dual peak pattern with EMA-binding testing. Common hereditary elliptocytosis cases are not discriminated from normal patients in either OF and EMA binding (band3) testing and this profile does not add confirmatory information for HE.
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.
Interpretation
An interpretive report will be provided.
Clinical Reference
1. King MJ, Garcon L, Hoyer JD, et al: International Council for Standardization in Haematology. ICSH guidelines for the laboratory diagnosis of nonimmune hereditary red cell membrane disorders. Int J Lab Hematol 2015 Jun;37(3):304-325. PMID: 25790109
2. Lux SE, IV: Anatomy of the red cell membrane skeleton: unanswered questions. Blood 2016 Jan 14;127(2):187-199 DOI:10.1182/blood-2014-12-512772. PMID: 26537302
3. Gallagher PG: Abnormalities of the erythrocyte membrane. Pediatr Clin North Am 2013 Dec;60(6):1349-1362. PMID: 24237975
4. Bianchi P, Fermo E, Vercellati C, et al: Diagnostic power of laboratory tests for hereditary spherocytosis: a comparison study in 150 patients grouped according to molecular and clinical characteristics. Haematologica 2012 Apr;97(4):516-523. PMID: 22058213
Day(s) and Time(s) Performed
Monday through Saturday
Analytic Time
4 days (not reported on Saturday or Sunday)CPT Code Information
85557-Osmotic fragility
88184-Flow cytometry; first cell surface, cytoplasmic or nuclear marker x 1
85060-Morphology review
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RBCME | RBC Membrane Evaluation, B | In Process |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
83141 | Band 3 Fluorescence Staining, RBC | In Process |
9064 | Osmotic Fragility, RBC | 34964-7 |
SCTRL | Shipping Control Vial | 40431-9 |
13065 | Spherocytosis Interpretation | 50595-8 |
37406 | Peripheral Blood Smear Review | 59465-5 |
37436 | Reviewed By | 18771-6 |
3306 | Osmotic Fragility, 0.50 g/dL NaCl | 23915-2 |
3307 | Osmotic Fragility, 0.60 g/dL NaCl | 23918-6 |
3308 | Osmotic Fragility, 0.65 g/dL NaCl | 23920-2 |
3309 | Osmotic Fragility, 0.75 g/dL NaCl | 23921-0 |
3310 | Osmotic Fragility Comment | 59466-3 |
Forms
1. Metabolic Hematology Patient Information (T810) in Special Instruction
2. If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen.