Antinuclear Antibodies (ANA), IgG by ELISA with Reflex to ANA HEp-2 Substrate, IgG by IFA and ENA Confirmation

Casandra

Casandra Test Code AR42992Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0050317CPT Codes 86038, 86039, 86225, 86235, 86256

Antinuclear Antibodies (ANA), IgG by ELISA with Reflex to ANA HEp-2 Substrate, IgG by IFA and ENA Confirmation

Also known as: ANA REF

Clinical Use

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Use

This test aids in the initial diagnosis of connective tissue diseases, such as systemic autoimmune rheumatic diseases (SARDs). It may be used to screen for antibodies against dsDNA, histones, SS-A, SS-B, Smith, Smith/RNP, Scl-70, Jo-1, centromeric proteins, and other nuclear antigens. It helps determine the presence of antinuclear antibodies, which are characteristic of various autoimmune disorders, including systemic lupus erythematosus (SLE) and Sjögren syndrome.

Special Instructions

Positive ANA detected by ELISA prompts further testing through reflex to indirect fluorescent assay (IFA) based on HEp-2 cell substrate. If ANA IgG is detected by IFA, further reflex testing for specific extractable nuclear antigen (ENA) antibodies is performed, with additional charges applying. The results may guide more specific serologic testing for confirmation.

Limitations

ANA testing lacks diagnostic specificity as ANAs are present in a variety of diseases, including cancers, autoimmune, infectious, and inflammatory conditions, and can also occur in healthy individuals. ELISA screening may have lower sensitivity compared to IFA, and negative results do not rule out systemic autoimmune rheumatic diseases. Reflex testing with IFA and further ENA antibody testing are needed for comprehensive evaluation.

Test Details

New York Approved