Osmotic fragility of red cells is defined as the ease with
which red cells are ruptured (hemolysed) when they are exposed to hypotonic
solution.
Osmotic fragility test assesses the integrity of the
membrane of red cells.
Increased Osmotic Fragility is seen in the following
Cells which have a lower surface to volume ratio such as spherocytes
from any cause have increased osmotic fragility is ssen in the following Conditions
- Hereditary»spherocytosis (HS)
- Autoimmune Hemolytic Anemias (A1HA)
- Hemolytic Disease of new bom
- Malaria
- Severe pyruvate kinase deficiency
- Other conditions in which spherocytes are found in the blood
Cells which have a high surface to volume ratio such as thin/hypochromic/target
cells have decreased osmotic fragility.
- Thalassemia
- Other hemoglobinopathies eg. HbC, HbS
- Iron deficiency anemia
- Sickle cel! anemia
- Post splenectomy
- Reticulocytosis
- Other conditions in which thin/target cells are found in the blood.
