What is this test?
This laboratory test is performed on a blood sample to detect the fragility of erythrocytes when exposed to a hypotonic solution. Erythrocytes become fragile when they have a low surface to volume ratio. Spherocytes are osmotically fragile when placed in a hypotonic solution because of their low surface to volume ratio. In this test, your erythrocytes will be added salt solutions of different concentrations to measure their fragility.
Why is this test performed?
This test is performed:
- To measure the level of hemolysis (fragility) in a blood sample
- To help in the diagnosis of hereditary spherocytosis and beta-thalassemia
- To help in the diagnosis of mild spherocytosis
- To monitor the efficacy of treatment.
- What are the sign and symptoms of hereditary spherocytosis?
- Increased osmotic fragility
- Anemia
- Jaundice
- Gall stones
- Liver enlargement
- Spleen enlargement
- What are the sign and symptoms of beta-thalassemia?
- Fatigue
- Slow growth
- Shortness of breath
- Anemia
- Jaundice
- Bone deformities
- Enlarged spleen
- What might affect the results?
- Recent blood transfusion
- Congenital non-spherocytic hemolytic anemia
- How to prepare for this test?
No special preparations are required for this test. However, inform your doctor about your complete medical history. Wear a half-sleeved or loose shirt to aid the collection of sample.
- What are the risks of this test?
Collecting blood from a vein is a very easy procedure and pose only minimum risk, including:
- Bruising
- Bleeding
- Infection
- Lightheadedness.
Reference range:
- Hemolysis start at 0.5% solution
- Hemolysis ends at 0.3% solution
- Interpretation of test results:
Causes of increased osmotic fragility:
- Hereditary spherocytosis
- Autoimmune spherocytosis
- Severe burns
- Poisoning
Causes of increased osmotic fragility:
- Thalassemia
- Iron deficiency anemia
- Sickle cell anemia