A patient's specimen is strongly positive in an ANA ELISA. Which of the following would not be an appropriate follow-up?

A patient's specimen is strongly positive in an ANA ELISA. Which of the following would not be an appropriate follow-up?

• A. Immunofluorescence test on HEp-2 cells
• B. Specific ENA ELISA tests
• C. Specific anti-DNA ELISA
• D. Rheumatoid factor assay

Answer: (D)

A strongly positive result in an ANA (antinuclear antibody) ELISA indicates the presence of autoantibodies that could be associated with various autoimmune disorders. In this context, appropriate follow-up tests aim to determine the specific type of autoantibodies present, as this can significantly assist in diagnosing the underlying condition. Utilizing an immunofluorescence test on HEp-2 cells is a common follow-up since this test provides detailed information about the pattern of fluorescence and can help identify specific autoantibodies present, making it a suitable step in further evaluating ANA positivity. Conducting specific ENA (extractable nuclear antigens) ELISA tests is also appropriate because they can help characterize the subset of autoantibodies present beyond the broad ANA findings. This includes testing for antibodies like anti-Smith, anti-RNP, or anti-Scl-70, which are useful for diagnosing specific autoimmune diseases. Performing a specific anti-DNA ELISA is relevant as well because antibodies against double-stranded DNA are particularly associated with systemic lupus erythematosus (SLE), which is one of the conditions that can lead to a positive ANA result. This helps to further refine the diagnosis. In contrast, a rheumatoid factor assay, although

A strongly positive result in an ANA (antinuclear antibody) ELISA indicates the presence of autoantibodies that could be associated with various autoimmune disorders. In this context, appropriate follow-up tests aim to determine the specific type of autoantibodies present, as this can significantly assist in diagnosing the underlying condition.

Utilizing an immunofluorescence test on HEp-2 cells is a common follow-up since this test provides detailed information about the pattern of fluorescence and can help identify specific autoantibodies present, making it a suitable step in further evaluating ANA positivity.

Conducting specific ENA (extractable nuclear antigens) ELISA tests is also appropriate because they can help characterize the subset of autoantibodies present beyond the broad ANA findings. This includes testing for antibodies like anti-Smith, anti-RNP, or anti-Scl-70, which are useful for diagnosing specific autoimmune diseases.

Performing a specific anti-DNA ELISA is relevant as well because antibodies against double-stranded DNA are particularly associated with systemic lupus erythematosus (SLE), which is one of the conditions that can lead to a positive ANA result. This helps to further refine the diagnosis.

In contrast, a rheumatoid factor assay, although