| Test Number | 081 |
| Method | Indirect Immunofluorescence (IFA) |
| Reference Range |
Qualitative
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| CPT Code | 83516 |
| Schedule Turnaround Time | Assay performed once every two weeks. Report availability is two weeks from the time of specimen receipt. |
| Specimen Requirements | Specimen need not be refrigerated or frozen. Collect 4-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into orange tube provided with IMMCO collection kits. Do not puncture top of orange tube. If separation facilities are not available, the blood can be sent in the tube used for collection. |
| Sample Stability | Requested Sample Volume: 4 mL
Minimum Sample Volume: 0.5mL
Sample Stability: Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.
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| Clinical Relevance | Autoantibodies against the cytoplasmic aminoacyl-tRNA synthetase (ARS) enzymes are the most frequently detected in adult patients with myositis. The first to be described and most common autoantigenic target is Jo-1 which is found in approximately 20% of idiopathic inflammatory myositis (IIM) patients. To date, autoantibodies to seven other ARS molecules—PL-7 (threonyl), PL-12 (alanyl), EJ (glycyl), OJ (isoleucyl), KS (asparaginyl), Ha (tyrosyl) and most recently Zo (phenylalanyl)—have been described collectively in 20% of patients with IIM (frequency of patients with each non-Jo-1 anti-ARS is between 1 and 5%).
Antibodies against PL-7 have a prevalence of approx. 3% to up to 6% in myositis patients, partly overlapping with SLE, SSc or interstitial lung fibrosis.
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| Antibodies |
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| Autoimmune Diseases |
- Dermato/Polymyositis
- Dermatopathology
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