Screening for antibodies against the SRP antigen is performed in patients with the potential for polymyositis, dermatomyositis, and overlay syndrome.
Antibodies against the SRP protein are a powerful laboratory marker for polymyositis and are also associated with an aggressive form, necrotic myopathy, and poor response to treatment. SRP antibodies are rarely detected in dermatomyositis and also rarely in interstitial lung disease. The titer of SRP antibodies correlates with disease activity. It has also been reported that SRP antibodies occur occasionally in cases of scleroderma and rheumatoid arthritis.
SRP (Signal Recognition Pattern) is a protein rich in amino acids Serine and Arginine, is found in cell cytoplasm and is important for the transport of molecules into the endoplasmic reticulum