L.E. Cells (Lupus Erythematosus Cells)

Function

The L.E. Cell test is a historical laboratory procedure used to detect Systemic Lupus Erythematosus (SLE). An L.E. cell is a neutrophil or macrophage that has ingested the denatured nuclear material of another cell. This phenomenon occurs in the presence of antinuclear antibodies (specifically anti-histone antibodies) that coat the nucleus of damaged cells.

Why it is Ordered

While largely replaced by more sensitive tests like ANA and Anti-dsDNA, the L.E. cell test may still be encountered in specific clinical settings or in regions where modern immunological assays are unavailable. It serves as a visual confirmation of the autoimmune process where antibodies are actively promoting the phagocytosis of nuclear material.

Associated Conditions

• Systemic Lupus Erythematosus (SLE): Positive in approximately 50-75% of active cases.
• Rheumatoid Arthritis: Occasionally positive.
• Hepatitis (Autoimmune): Can sometimes show L.E. cell presence.
• Drug-Induced Lupus: Certain medications can trigger the formation of these cells.

Clinical Importance

The L.E. cell test is less sensitive than the ANA test, meaning a negative result does not rule out Lupus. However, a positive result is quite specific for SLE. Due to the requirement for manual microscopic examination and the subjective nature of identifying the cells, modern rheumatology favors standardized ELISA or Immunofluorescence assays over the L.E. cell preparation.