L.E. cells are neutrophils or macrophages that have engulfed denatured nuclear material, primarily associated with lupus erythematosus and similar connective tissue disorders. The presence of L.E. cells is indicative of lupus, while diagnostic testing methods include the rotary bead and fluorescent antibody methods. Although L.E. cell testing has largely been replaced by antinuclear antibody testing for diagnosing systemic lupus erythematosus, it remains a relevant aspect in the evaluation of related conditions.

1. DEMONSTRATION
OF LE CELLS
PRESENTED BY,
S.SHRUTHI VASAN
III BSC.CLT
Dr.NGP ARTS & SCIENCE COLLEGE

2. LE CELLS:
 An LE cell is a Neutrophil or Macrophage that has
phagocytised (engulfed) the denatured nuclear material
of another cell. The denatured material is an
absorbed haematoxylin body (basophilic particle also
called an LE body).
 They are a characteristic of lupus erythematosus, but
also found in similar connective tissue disorders.
 The LE cell was discovered in bone marrow in 1948 by
Malcolm McCallum Hargraves (1903–1982), a
Physician and Practicing Histologist at the Mayo Clinic.
 Classically, the LE cell is analyzed microscopically, but it
is also possible to investigate this phenomenon by flow
cytometry.

3. FLOW CYTOMETER

6. SLE
 Persons having lupus erythematosus, one of the "collagen"
diseases, have an abnormal plasma protein that causes swelling
and breakdown of certain blood cell nuclei in vitro.
 This degenerated nuclear material attracts phagocytic cells,
particularly segmented neutrophils, which engulf this nuclear
mass.
 The resulting phagocyte and inclusion material is termed an
"L.E." cell.
 Lupus erythematosus is a chronic, sometimes fatal, disease of
unknown etiology.
 The peculiar skin eruption across the nose and cheeks (butterfly
rash) and arthritis can be accompanied by various visceral
manifestations.
 Often the rash is not present, and diagnosis depends on
demonstration of the L.E. cell.
 Frequently the earliest symptoms appear after intense exposure
to sunlight.
 Leukopenia, thrombocytopenia, and an elevated sedimentation
rate are some of the clinical signs of the disease.

9. Two methods of demonstrating the L.E. cell
and antinuclear antibodies are the
 Rotary bead method and
 Fluorescent antibody method.
The rotary bead method is positive in 75-80
erythematosus.
The fluorescent antibody method is positive in
95-100 patients with lupus erythematosus.
The fluorescent antibody method requires
equipment that limits its use to larger laboratories.

10. ROTARY BEAD METHOD
Principle
Leukocytes are broken down in vitro allowing
the abnormal plasma protein to react on the altered
nuclear material. Incubation enhances the nuclear
deterioration and phagocytises. Slides are prepared
and examined for the peculiar "L.E." cell.

11.  Free masses of lysed nuclear material, with or
without polymorphonuclear leukocytes clustered
about them (rosette formation), are suggestive of
the L.E. phenomenon.
 Observing "rosettes" should encourage the
technician to repeat examinations and further
search for the true "L.E." cells.
 A positive report should not be made without the
identification of this cell. The inclusion body with the
leukocyte is homogeneous and has no chromatin
pattern. This feature distinguishes the true "L.E." cell
from the "tart" cell (nucleophagocytosis).
 This latter cell contains an engulfed, damaged
nucleus, usually that of a lymphocyte, which still
contains a recognizable chromatin pattern and a
distinct nuclear membrane.

13. COLLECTION OF SAMPLE::
Lupus erythematosus (LE) cell testing is
performed using any of the following:
 Heparinized bone marrow
 Heparinized venous blood
 Oxalated venous blood
 Defibrinated venous blood
 Clotted venous blood
 LE factor and donor cells
LE Factor:
An Antibody found in the serum found in SLE
Patients.

14.  Obtaining bone marrow is usually distressing for the
patient; therefore, the buffy coat from venous blood is
an adequate substitute.
 If the equipment for buffy coat is unavailable, an
untreated venous blood sample is left to clot (from 20-
120 minutes) and the plasma removed. The residual
clot is passed through a wire mesh and centrifuged
for 5 minutes to obtain a buffy coat. This buffy coat is
then smeared on glass slides to search for LE cells. [2]
 The test may be performed by mixing the patient's
plasma, serum, or serous effusions as a source of LE
factor with bone marrow from a donor subject.

15. CONSIDERATIONS:
 The ideal temperature to perform this test is 22°C,
and the process may be hastened by incubation at
37°C.

16. INTERPRETATION
o A lupus erythematosus (LE) cell test is considered
positive when approximately 2%-30% of the cells
seen on the slide in the neutrophil count are LE cells.
o A smear is considered positive when 10 or more
characteristic LE cells are seen during a 15-minute
search, associated with the presence of extracellular,
amorphous, nuclear masses.
o The presence of LE cells indicates lupus.
o Negative findings on LE cell testing exclude (deny) a
diagnosis of systemic lupus erythematosus(SLE).

17. o Positive reactions are also seen in
1. Rheumatoid arthritis
2. Chronic hepatitis(lupoid)
3. Scleroderma
4. Dermatomyositis
5. Polyarteritis nodosa
6. Acquired hemolytic anemia
7. Hodgkin disease
o It may also be positive in persons taking
phenylbutazone(Fever & RE) and hydralazine(BP)

18. APPLICATION
 Lupus erythematosus (LE) cell testing was once
performed to diagnose systemic lupus
erythematous but has been replaced for this purpose
by antinuclear antibody testing.