Connective Tissue Diseases Cascade, Serum

Casandra

Casandra Test Code MC84899Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID CTDCCPT Codes 83516, 86038, 86200, 86225, 86235

Connective Tissue Diseases Cascade, Serum

Clinical Use

Use

This test is useful for the evaluation of patients with signs and symptoms compatible with connective tissue diseases (CTDs). It is specifically recommended for the initial evaluation of patients in clinical situations with a low prevalence of CTDs. The presence of significantly elevated cyclic citrullinated peptide (CCP) antibodies is suggestive of rheumatoid arthritis (RA) or risk for developing disease in at-risk individuals. However, additional testing for rheumatoid factor (RF) and inflammatory markers, not included in this cascade, are important for optimal diagnosis. The test is not recommended for situations with high prevalence of CTDs or follow-up evaluation of patients with known CTDs.

Special Instructions

This test is performed Monday through Saturday. If antinuclear antibodies are greater than or equal to 3.0 U, additional tests such as antibodies to double-stranded DNA (dsDNA), extractable nuclear antigen evaluation, ribosome P, and centromere are performed automatically at an additional charge.

Limitations

The presence of detectable levels of antinuclear antibodies (ANA) in solid-phase immunoassays, such as enzyme-linked immunosorbent assay (ELISA), is not specific for connective tissue disease. Positive results may occur prior to the onset of clinical diseases as well as in the absence of connective tissue disease. Negative ANA by ELISA results may not be reliable for evaluating patients at risk for systemic sclerosis and inflammatory myopathies. Weak-to-moderate positive results for cyclic citrullinated peptide antibodies may occur in patients with connective tissue diseases other than rheumatoid arthritis.

Test Details

FDA Approved

New York Approved

Methodology

Immunoassay (ELISA)

Biomarkers

Targets summarized.

Antinuclear AntibodiesCentromere BCyclic Citrullinated Peptide AntibodiesDouble-Stranded DNA AntibodiesHistidyl tRNA synthetase (JO1)RNP 68 and A (RNP)Smith (Sm)Topoisomerase 1 (Scl-70)