Lab Test

Myositis Autoantibodies

PL-7, PL-12, Mi-2, Ku, EJ, OJ, SRP, Jo-1, Quest #3242, EPIC: LAB6501, SOFT: XMA

Test Codes

Quest #3242, EPIC: LAB6501, SOFT: XMA

Specimen Collection Criteria

Collect: Two plain Red-top tubes.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within four hours of collection. Transfer serum to two plastic transport tubes and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 6.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 2.0 mL)

Rejection Criteria

  • Gross hemolysis and lipemia.
  • Gross Icteric specimens.
  • Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within four hours of collection. Transfer serum to two plastic transport tubes and refrigerate (2-8°C or 36-46°F).

Transport: 6.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 2.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 days
Refrigerated (2-8°C or 36-46°F): 7  days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Sendout Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics Nichols Institute of Valencia, Valencia, CA.

Performed

Tuesday – Thursday.
Results available in 4-10 days.

Reference Range

PL-7 Autoantibodies: None Detected.
PL-12 Autoantibodies: None Detected.
MI-2: Autoantibodies: None Detected.
KU Autoantibodies: None Detected.
EJ Autoantibodies: None Detected.
OJ Autoantibodies: None Detected.
SRP Autoantibodies: None Detected.
Jo-1 Autoantibodies: Less than 1.0.

Test Methodology

Radioimmunprecipitation Immunoassay.

Clinical Utility

A high proportion of patients with idiopathic inflammatory myopathies (IIMs) which include polymyositis, dermatomyositis and myositis associated with other rheumatic diseases, have autoantibodies directed against aminoacyl-transfer RNA (tRNA) synthetases (myositis-specific antibodies), which are a group of cellular enzymes that catalyze the binding of one amino acid to its tRNA. Autoantibodies to eight of these synthetases, histidyl (Jo-1), threonyl RS (PL-7), alanyl RS (PL-12), isoleucyl RS (OJ), glycyl RS (EJ), leucyl RS, lysyl RS and GluPro RS are reported in IIMs. Histidyl-tRNA synthetase (Jo-1) antibodies are the most common (20-30% of IIMs). Anti-PL-7 and PL-12 are found in 3%, anti-EJ occur in 3%, OJ occur in 2%, and anti-GluPro RS, leucyl RS and lysyl RS occur in less than 1%. Aminoacyl-tRNA synthetase autoantibodies are strongly also associated with interstitial lung disease (ILD), arthritis and Raynaud phenomenon.

CPT Codes

83516x5, 86235x3.

Contacts

Last Updated

10/23/2019

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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.