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HelpTest Code LAB3162 Hereditary Spherocytosis Screen
Clinical System Name
Hereditary Spherocytosis Screen
Synonyms
HS Screen
Hereditary spherocytosis screen
Sample Requirements
Specimen: Whole Blood
Container(s): Lavender/EDTA
Preferred Vol: 3 mL
Minimum Vol: 0.5 mL or 1 lavender microtainer
Note:
Specimen can be collected 24 hours a day, 7 days a week. Both venipuncture and capillary collections are acceptable. Test may be added to CBC specimen in lab. Pre-transfusion specimen is preferred. No patient age restriction for testing.
Processing Instructions
Reject due to: n/a - send to lab
Spin: N
Aliquot: N
Temp: RT
Storage location: Days: Transport specimen, community services requisition, if applicable, and labels to the Cell Markers Lab (station #181). Eves/Nights/Off Hours: Store specimen, requisition (if applicable) and labels in the Cell Markers box in CPA refrigerator #1.
Off-site collection: ent in specimens drawn from outside locations are acceptable. Refrigerate EDTA whole blood and transport to Seattle Childrens as soon as possible. Please send a copy of the patient's most recent CBC and differential results with the specimen. Note: room temp is acceptable up to 48 hours, but refrigeration is recommended for longer specimen stability (96 hours).
Stability
| Temperature | Time |
|---|---|
| Room temp | 48 hours |
| Refrigerated |
96 hours |
| Frozen | N |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y - with pathologist approval | collected daily; performed M-Sat | 2-3 days |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Cell Markers
Phone Number: 206-987-2560
CPT Codes
| CPT CODE(S) |
|---|
| 88184 |
Methodology
Method: Flow Cytometry
Analytical Volume: 0.1 mL
Limitations: Specimens from newborns are acceptable for testing by this method
| KNOWN FALSE POSITIVES: |
Southeast Asian ovalocytosis |
|
Congenital dyserythropoietic anemia type II |
|
|
Cryohydrocytosis |
|
| KNOWN FALSE NEGATIVES: |
normal EMA-binding in single ankyrin-deficiency HS |
| OTHER CAUSES OF INCREASED FLUORESCENCE (POSSIBLE FALSE NEGATIVE): | |
|
BLOOD TRANSFUSIONS |
According to reports in the literature, spherocytic red cells are detectable in the peripheral blood of a transfused HS patient, provided that a blood transfusion given does not exceed one-half of the total blood volume. In patients that have had a recent red blood cell transfusion a second peak with increased fluorescence may be detected or a single peak with an increased HPCV. |
|
RETICULOCYTES |
Retics have increased red cell membrane proteins that bind EMA. In patients with significantly elevated reticulocytes, a second peak with increased fluorescence may be detected or a single peak with an increased HPCV. |
Reference Range
| Negative |
Description
This test is a flow cytometric analysis of the red blood cells band 3 membrane protein stained with the dye, Eosin-5-maleimide. The assay is used in the evaluation for Hereditary Spherocytosis. Note: The osmotic fragility test is no longer available.