LE cell phenomenon

Sample for LE cell phenomenon

• 5 to 10 mL of 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.  (SLE).

Systemic lupus erythematosus

SLE is a combination of various signs and symptoms like:

1. Systemic symptoms like fever, malaise, and inflammation of serous membranes like pericardium.
2. Facial skin rash.
3. Arthritis.
4. Renal diseases like nephritis.
5. SLE is more common in females, predominantly young or middle-aged adults.
   1. In one study, the mean age is 30 years (the majority between 14 to 40 years).
   2. Lesser patients were seen between the age of 40 and 55 years.
   3. Few cases were seen in infancy to 14 years and over 55 years.
6. Hepatomegaly was seen in 30% of the cases.
7. Splenomegaly was seen in 20% of the cases.
8. Lymphadenopathy was seen in 50% of the cases.
9. Lab findings of SLE:
10. Anemia is present in 60% to 75% of the cases.
    1. Anemia is mild to moderate, normocytic normochromic.
    2. <10% develop autoimmune hemolytic anemia.
11. Leucopenia is seen in 50% of the patients.
12. 15% may develop thrombocytopenia.
13. 30% of the patients have positive direct Coombs test.
14. There may be abnormal plasma proteins like:
    1. Cold-precipitable cryoglobulins.
    2. Circulating anticoagulants.
    3. Autoantibodies.
    4. Circulating immune complexes.
    5. Raised gamma-globulins.
    6. Syphilis serologic reactions.
    7. False positive RA factor.
    8. Some rare phenomena.
15. In the case of active nephritis, there is decreased C3 and C4.

Pathophysiology of LE cell phenomenon

1. Systemic lupus erythematosus is a typical autoimmune disease.
2. It is a systemic rheumatic disease.
3. The etiology is unknown, but the primary defect is in the immune system.
4. 50 to 70 new cases are diagnosed per year per million people.
5. The range of the disease is:
   1. Mild limited to a photosensitive facial rash and transient diffuse arthritis.
   2. Life-threatening involvement of:
      1.  Kidneys.
      2. Cardiovascular system.
      3. Respiratory system.
      4. Central nervous system.

The LE cell definition:

1. A LE cell is either a normal segmented white blood cell or another phagocytic cell with an engulfed homogenous and swollen nucleus.
2. This is a degenerating nucleus which may be white blood cells or lymphocytes.
3. In SLE, there are various self-antigens like:
   1. Nuclear histones and proteins.
   2. IgG
   3. RBCs
   4. DNA and RNA
   5. Platelets.

Mechanism of injury in SLE:

1. Autoantibodies form against all the above antigens.

2. Autoantibodies give rise to a complex of Ag+Ab, leading to damage by Type 3 and Type 2 hypersensitivity reactions.

3. Antinuclear antibodies cause damage to the nucleus, which degenerates and gives rise to a homogeneous body called a hematoxylin body.
4. Mature neutrophilic polymorphonuclear leukocyte phagocytized a spherical, homogeneous-appearing inclusion (hematoxylin body).
   1. This is the neutrophil leucocyte with the presence of homogeneous red-purple inclusion that distends the cells and pushes the nucleus to one side.
   2. This inclusion is derived from the nuclear material of degenerating leukocytes as the outcome of antibodies against the nuclear material.
   3. These inclusions are characteristic of lupus erythematosus but are also found in other autoimmune diseases.

Procedure for LE Cell Phenomenon:

1. Take 5 to 10 ml of blood.
   1. Add glass beads or traumatize the cells with a glass rod.
2. Incubate for 20 to 30 minutes at 37 °C.
3. There will be a formation of LE cells during incubation.
4. Bone marrow may be taken for this phenomenon.
5. Centrifuge the blood sample and make the slide from the buffy coat or the area of the white cell.

Typical LE cell body in the cell

Le cell phenomenon

Result of Le cell phenomenon

1. The neutrophils show intracytoplasmic inclusion pushing the homogenous degenerated nucleus to the periphery.
2. Le cells may be found in CSF, Joint, pleural, pericardial fluid, and blister fluid smears.
3. Now, this test is obsolete because of so many other labs. Diagnostic tests.

Positive LE cells are seen in the following:

1. Systemic lupus erythematosus. These are positive in 95% of the cases.
2. Drug-induced lupus erythematosus. These are seen in 80 to 95 % of the cases.
3. Other autoimmune diseases show LE cells in less than 20 % of the cases.

Questions and answers: