INDIVIDUAL TEST 481

KS antibodies (Asparaginyl-tRNA-Synthetase)

IndicationSuspicion of polymyositis/dermatomyositis.MethodRadioimmunoprecipitationResponseThe test result is given as negative, borderline or positive. Bordeline and positive values are reported with a ratio.InterpretationAntibodies against to KS are a type of anti-synthetase antibodies that can be detected in <5% of patients with inflammatory myositis (poly-/dermatomyositis). Anti-KS antibodies are directed against asparaginyl-tRNA-synthetase and are primarily associated with interstitial lung disease. Muscular symptoms may be discreet or missing and the level of creatine kinase in blood is often only slightly elevated. Arthritis and/or Raynaud phenomena have been described and malignancies have been reported to occur in up to 15% of these patients.