Myositis Interstitial Lung Disease Panel (includes: 050, 053, 081, 082, 083, 084, 085, 086, 087, 088, 192, 196)

Category: Rheumatology
Test Code: 198
Disease: Dermato/Polymyositis
Methodology: Line Immunoassay
Reference Range: Qualitative
CPT Code: 83516 (x12)
Schedule / Turnaround Time: Assay performed once per week. Report availability is three - four weeks from the time of specimen receipt.
Specimen Requirements:

Specimen need not be refrigerated or frozen. Collect 5-10 ml of blood in a red top or serum separator tube.

Sample Stability:

Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.


Interstitial Lung Disease (ILD) co-occurs with autoimmune inflammatory myopathy (IM) patients in between 10-20% of the cases. Depending on the autoantibody present the occurrence of ILD can be seen in 2/3 of the IM patients.

The prevalence of ILD in anti-synthetase (Jo-1, PL 7, PL 12, EJ, OJ, KS) positive inflammatory myopathy patients was found to be as high as 73%.

Anti-Ku antibodies are detected in multiple autoimmune diseases and has high co relation to these patients developing ILD.

In SRP positive myositis patients, the prevalence of ILD has been documented at 23%.

Anti-SSA 52 kD antibodies commonly co-occur with other myositis related antibodies. They are found in 1/3rd of CADM140 kD positive patients, and are also associated with anti-synthetase antibodies.

Antibodies to PM/Scl are found in 40-50% of Scleroderma-polymyositis overlap syndrome patients and correlate with a benign course of ILD.

Anti-clinically amyopathic dermatomyositis CADM 140/MDA5 autoantibodies are specifically detected in Japanese patients with dermatomyositis and are known to have a strong association with rapidly progressive interstitial lung disease (RP-ILD). Japanese studies have shown that anti-MDA5 is seen in between 38%-50 of juvenile dermatomyositis (JDM patients), all of whom had ILD. A small subsets of with very high titers of antiMDA5 had RP-ILD. The reported rates of ILD in USA patients with JDM are far lower than in adult DM. The risk of P140 kD antibody positive DM patients developing ILD reached close to 100%.