OSMOTIC FRAGILITY ERYTHROCYTES

General Information

HLAB/HOL Code: RCF
UPHSM LIS Test #: 2944
Schedule: Monday - Saturday
Testing Time: 2 days (not reported on Sat. or Sun.)
Testing Lab: Mayo Labs

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 5.0 mL of Fresh Whole Blood
Temperature: Refrigerate
Tube Type: 1 LAV Top EDTA
Collection Info:
Specimens must arrive within 72 hours of draw.
1. Draw blood in a lavender top (EDTA) tube, and send 5.0 mL of  fresh EDTA whole blood refrigerated. Do not transfer blood to other
     containers.
2. Include a control specimen drawn at the same time from a normal,  unrelated individual: draw blood in a lavender top (EDTA) tubes,
     and send 5.0 mL of fresh EDTA whole blood refrigerated. Do not transfer  blood to other containers. Label clearly on outermost label
     normal control. Indicate sex of control on tube(s) label.
3. Specimens cannot be frozen.
Note:
Indicate patient's date of birth on request form.
Volume: 5.0 mL Whole Blood Normal Control
Temperature: Refrigerate
Tube Type: 1 LAV Top EDTA
Collection Info:
See above

Methods

Osmotic Lysis

Clinical Utilities

Spherocytes are osmotically fragile cells that rupture more easily in a hypotonic solution than do normal red blood cells. Because they have a low surface area: volume ratio, they lyse at a higher osmolarity than do normal discocyte (RBCs). Cells that have a larger surface area: volume ratio, such as target cells or hypochromic cells are more resistant to lysing. After incubation, an increase in hemolysis is seen in hereditary spherocytosis.  The test is helpful in confirming or detecting mild spherocytosis.  Infrequently, other hemolytic disorders may also be associated with positive tests, as in patients with congenital nonspherocytic hemolytic anemia due to glucose-6-phosphate dehydrogenase (G-6-PD) or pyruvate kinase deficiency. Patients with an immunohemolytic anemia, or who have recently received a blood transfusion may also have increased RBC lysis.

CPT Codes

85557

* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Reference Range

0.50 g/dL NaCl (unincubated)
Males: 0.0-47.8% hemolysis
Females: 0.0-31.1% hemolysis

0.60 g/dL NaCl (incubated)
Males: 18.7-67.4% hemolysis
Females: 10.9-65.5% hemolysis

0.65 g/dL NaCl (incubated)
Males: 4.4-36.6% hemolysis
Females: 0.2-39.3% hemolysis

0.75 g/dL NaCl (incubated)
Males: 0.8-9.1% hemolysis
Females: 0.0-10.9% hemolysis