LE Cell

Function

The Lupus Erythematosus (LE) cell is a neutrophil or macrophage that has ingested the denatured nuclear material of another cell. This phenomenon occurs when antinuclear antibodies (ANA) in the patient's serum react with damaged nuclei. While historically significant, this test is now largely considered obsolete, having been replaced by more sensitive and specific tests like ANA (Antinuclear Antibody) and anti-dsDNA.

Why it is Ordered

In modern medicine, the LE cell test is rarely the first line of investigation. It might be ordered in resource-limited settings or as a confirmatory finding in specific cases of suspected Systemic Lupus Erythematosus (SLE). It was originally designed to help diagnose lupus, but its lack of sensitivity (it is negative in 20-30% of SLE patients) and lack of specificity (it can be positive in other diseases) makes it less reliable than newer assays.

Associated Conditions

• Systemic Lupus Erythematosus (SLE): The primary condition associated with a positive LE cell prep.
• Other Autoimmune Diseases: Positive results may occur in Rheumatoid Arthritis, Scleroderma, or Chronic Active Hepatitis.
• Drug-Induced Lupus: Certain medications (like hydralazine or procainamide) can induce the formation of LE cells.

Diagnostic Evolution

Because the LE cell requires specific laboratory manipulation and subjective microscopic identification, it is prone to technician error. Rheumatologists now rely on the 'American College of Rheumatology' criteria, which favor ANA titers and specific antibody profiles over the LE cell prep.