Specimen Information

Type

Gold, SST

Volume

1.0 ml

Transport Info

Refrigerated

Fasting Required?

False

Clinical Significance

Presence of Jo-1 antibody is found in patients with pure polymyositis, pure dermatomyositis or myositis associated with another rheumatic disease or with interstitial lung disease.

The term "anti-nuclear antibodies" (ANA) describes a variety of autoantibodies that react with constituents of cell nuclei including DNA, RNA, and several proteins and ribonucleoproteins. These autoantibodies occur with high frequency in patients with connective tissue or rheumatic diseases, especially systemic lupus erythematosus (SLE). The current trend in diagnosing and managing connective tissue disease is to combine a sensitive ANA screening test with more specific follow-up tests such as antibodies to double stranded DNA (dsDNA) and extractable nuclear antigens (ENA).The newer ENA tests are becoming especially important as they provide both diagnostic and prognostic information. Antibodies to the autoantigen Jo-1 (histidyl-RNA synthetase) are found in a subgroup of connective tissue disease patients with pure polymyositis, pure dermatomyositis, or myositis associated with another rheumatic disease. Antibodies to Jo-1 are found in 18-36% of all patients satisfying the criteria for myositis. The antibody is more common in polymyositis than dermatomyositis and rarely found in other disease states. Antibodies to Jo-1 are strongly associated with interstitial lung disease, with nearly all Jo-1 positive patients showing evidence of lung involvement. A relationship of Jo-1 antibody titer and disease activity has been reported, but to date this has not been confirmed.