Which old autoantibody test has been replaced by ANA testing?

• A. dsDNA
• B. RF
• C. Anti-CCP
• D. LE cell test

Answer: (D)

Antinuclear antibody testing provided a more practical and sensitive way to screen for autoimmune nuclear-targeting antibodies than older methods. The LE cell test looked for a rare phenomenon where a neutrophil ingested nuclear material from another cell, producing LE cells; it was labor-intensive, required fresh cells, and had limited sensitivity and standardization. In contrast, ANA testing uses a standardized immunofluorescence approach to detect a broad range of antibodies against nuclear components, making it a more reliable first-line screen for systemic lupus erythematosus and related conditions. When ANA is positive, more specific tests (such as dsDNA, Sm, RNP, SSA/SSB) can be pursued to refine the diagnosis. Hence, the LE cell test fell out of routine use as ANA testing became the preferred screening tool.