A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Cytosolic 5'-Nucleotidase 1A (cN-1A) Antibody (IgG)
Test Code10266
CPT Codes
83516
Preferred Specimen
0.5 mL serum
Minimum Volume
0.3 mL
Other Acceptable Specimens
Plasma collected in: EDTA (lavender-top) tube
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 7 days
Refrigerated: 14 days
Frozen: 28 days
Refrigerated: 14 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Moderate to gross hemolysis
Methodology
Enzyme Linked Immunosorbent Immunoassay (ELISA)
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Set up: Tues, Thurs, Sat; Report available: 3-6 days
Reference Range
<15 Units | Negative |
15-19 Units | Borderline |
≥20 Units | Positive |
Clinical Significance
The cN-1A Ab assay is a useful aid for the diagnosis of inclusion body myositis (IBM). The analytical sensitivity of this assay is 35-70%, based on published reports [1, 2]. In our validation study with 120 healthy adult subjects, 1.7% had a positive cN-1A Ab result and 6.7% had an equivocal result. However, published reports and our own internal studies suggest that patients with Sjogren’s syndrome, systemic lupus erythematosus, dermatomyositis (DM), or polymyositis (PM), are significantly more likely to have a positive cN-1A Ab result [1, 2, 3]. In contrast, patients presenting clinically with IBM rarely produce autoantibodies associated with a diagnosis of DM or PM [3]. Therefore, cN-1A Ab results must be interpreted in context with other details of the patient’s clinical evaluation.
References
1. Larman HB, et al. Cytosolic 5'-nucleotidase 1A autoimmunity in sporadic inclusion body myositis. Ann Neurol. 2013 Mar;73(3):408-18.
2. Felice KJ, et al. Neuromuscul Disord. 2018 Aug;28(8):660-664
3. Kramp SL, et al. Auto Immun Highlights. 2016 Dec;7(1):16. doi: 10.1007/s13317-016-0088-8
References
1. Larman HB, et al. Cytosolic 5'-nucleotidase 1A autoimmunity in sporadic inclusion body myositis. Ann Neurol. 2013 Mar;73(3):408-18.
2. Felice KJ, et al. Neuromuscul Disord. 2018 Aug;28(8):660-664
3. Kramp SL, et al. Auto Immun Highlights. 2016 Dec;7(1):16. doi: 10.1007/s13317-016-0088-8
Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
33608 Ortega Highway |
San Juan Capistrano, CA 92675-2042 |
Last Updated: December 22, 2022