LE cell phenomenon (Lupus erythematosus cell)
LE cell phenomenon
Sample for LE cell phenomenon
- 5 to 10 mL venous blood of the patient is taken and is traumatized by a glass rod or glass beads.
Indication for LE cell phenomenon
- This is done to diagnose Systemic lupus erythematosus.
Pathophysiology of LE cell phenomenon
Systemic lupus erythematosus is a typical autoimmune disease.
- It is a systemic rheumatic disease.
- Etiology is unknown but the primary defect is in the immune system.
- 50 to 70 new cases are diagnosed per year per million of the people.
- The range of the disease is:
- Mild limited to a photosensitive facial rash and transient diffuse arthritis.
- Life-threatening involvement of:
- Cardiovascular system.
- Respiratory system.
- Central nervous system.
The LE cell definition:
- A LE cell is either a normal segmented white blood cell or another phagocytic cell with the engulfed homogenous and swollen nucleus.
- This is a degenerating nucleus which may be white blood cell or lymphocyte.
- In SLE there are various self-antigens like:
- Nuclear histone and proteins.
- DNA and RNA
- Autoantibodies form against all the above antigens.
- Autoantibodies give rise to a complex of Ag+Ab which will lead to damage by Type 3 and Type 2 hypersensitivity reactions.
- Antinuclear antibody cause damage to the nucleus which degenerates and gives rise to a homogeneous body called a hematoxylin body.
- Mature neutrophilic polymorphonuclear leukocyte, which has phagocytized a spherical, homogeneous-appearing inclusion (hematoxylin body).
- This is the neutrophil leucocyte with the presence of homogeneous red-purple inclusion that distends the cells and pushes the nucleus to one side.
- This inclusion is derived from the nuclear material of degenerating leukocytes as the outcome of antibodies against the nuclear material.
- These inclusions are characteristic of lupus erythematosus, but also found in other autoimmune diseases.
Procedure for LE Cell Phenomenon:
- Take 5 to 10 ml of blood.
- Add glass beads or traumatized the cells with a glass rod.
- Incubate for 20 to 30 minutes at 37 °C.
- There will be a formation of LE cells on incubation.
- Bone marrow may be taken for this phenomenon.
- Centrifuge the blood sample and make the slide from the buffy coat or from the area of the white cell.
- The neutrophils show intracytoplasmic inclusion pushing the homogenous degenerated nucleus to the periphery.
- Now, a day this test is obsolete because of so many other lab.diagnosticv tets.
Positive LE cells are seen in:
- Systemic lupus erythematosus. These are positive in 95% of the cases.
- Drug-induced lupus erythematosus. These are seen in 80 to 95 % of the cases.
- Other autoimmune diseases show LE cell in less than 20 % of the cases.