The histidyl-tRNA synthetase is a cytoplasmic enzyme which catalyzes the binding of amino acid histidine to histidine-specific transfer RNA.  

Polymyositis and Dermatomyositis (PM/DM) are autoimmune diseases which primarily affect the muscles and/or the skin, although other organs may also be involved (lung and heart). The illnesses severely affect the quality of life and may, if not diagnosed and treated rapidly, progress over time to a life-threatening state. The diagnosis of PM/DM however is difficult since overlap syndromes with features of other diseases such as Scleroderma are frequent.

The most important autoantibodies for the serological diagnosis of PM/DM are antiaminoacyl-tRNA synthetases antibodies (such as anti-jo-1 antibodies). The anti-synthetase syndrome is characterized by myositis with a high frequency of Interstitial Lung Disease (ILD).

Jo-1 antibodies are highly specific of autoimmune Myositis. The diagnostic specificity is reported as nearly 100 %. Furthermore Jo-1 is considered as a useful prognostic marker for more severe clinical course, frequent active episodes and a poor prognosis.


Antigen used by D-tek

Recombinant, human, expressed in Baculovirus-infected Sf9 cells (for more information on our antigens click here)