ANTI-JO-1 ANTIBODIES

CLINICAL UTILITY:

Jo-1 antigen is a saline extractable nuclear antibody which is a component of histidyl-tRNA synthetase. Approximately 30% of patients with Polymyositis (PM) have anti-Jo-1 antibodies in their sera. Presence of the antibodies appears to identify patients with a higher incidence of extramuscular symptoms such as interstitial pulmonary fibrosis and polyarthritis, along with other immunologic abnormalities. The antibody also occurs in dermatomyositis (DM), PM-DM overlap syndromes and other connective tissue diseases, though less frequently.

METHOD DESCRIPTION:

Counterimmunoelectrophoresis (CIE) is used to screen and identify sera containing antibodies to Jo-1. Results of the identification are reported as positive or negative for the antibody. If an anti-ENA Screen/ID has been ordered instead of anti-Jo-1, the following report would indicate the potential for presence of anti-Jo-1:"‘Unidentified antibody present, suggest ordering anti-Jo-1 (myositis precipitin) if clinically indicated." If the anti-ENA screen is negative, the test for antibodies to Jo-1 (as well as antibodies to other extractable nuclear antigens) is negative.

REFERENCE RANGE:

Negative.

SPECIMEN REQUIREMENTS:

0.5 ml serum. Freeze.