Geisinger Medical Laboratories Test Catalog
CYTOSOLIC 5'-NUCLEOTIDASE 1A (CN-1A) ANTIBODY (IGG) |
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ORDERING INFORMATION: |
Geisinger Epic Procedure Code: LAB1346 Geisinger Epic ID: 53309 | |
SPECIMEN COLLECTION |
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Specimen type: |
Serum | |
Preferred collection container: |
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Alternate Collection Container: |
6 mL red-top (plain, non-serum separator) tube
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Specimen required: |
0.5 mL serum; minimum 0.3 mL. | |
SPECIMEN PROCESSING |
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Specimen processing instructions: |
Centrifuge and aliquot. | |
Transport temperature: |
Room temperature. | |
Specimen stability: |
Room temperature: 7 days. Refrigerated: 14 days. Frozen: 28 days. | |
Rejection criteria: |
Moderate to gross hemolysis. | |
TEST DETAILS |
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CPT code(s): |
83516 | |
Note: The billing party has sole responsibility for CPT coding. Any questions regarding coding should be directed to the payer being billed. The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only. | ||
Methodology: |
Enzyme-Linked Immunosorbent Assay (ELISA) |
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Synonyms: |
Quest test code 10266
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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. |