Connective Tissue Diseases Cascade, Serum
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.
FDA ApprovedNew York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 95267-1
- 94875-2
- 33935-8
- 69048-7
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into plastic vial. Preferred collection container is serum gel, acceptable is red top.
Causes for Rejection
Gross hemolysis, Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 21 days |
| Frozen | 21 days |