Test Background Myositis-specific antibodies are tested by immunoblot, which includes Mi-2, Ku, Pm-Scl, Jo-1, PL-7 and PL-12 antibodies.
Myositis is an inflammatory disease of the skeletal muscles. Myositis may be hereditary or caused by infections, malfunctions of the immune system or by toxins. Polymyositis in an inflammatory disease of the skeletal muscles with perivascular lymphocytic infiltration. Its aetiology is unknown. In case of skin involvement the disease is known as dermatomyositis.