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The Cytosolic 5'-Nucleotidase 1A (cN-1A) Antibody (IgG) test contains 1 test with 1 biomarker.
Clinical Significance
Cytosolic 5'-Nucleotidase 1A (cN-1A) Antibody (IgG) - 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.
Reference Range(s)
<15 Units | Negative |
15-19 Units | Borderline |
≥20 Units | Positive |
Alternative Name(s)
MUP44 AB,cN1A,sIBM,Inclusion Body Myositis,Anti-IBM,NT5C1A,sporadic IBM