Antibodies to the PM/Scl complex, also known as the human exosome complex, belong to the anti-nucleolar antibodies and are mainly found in patients with PM/SSc overlap syndrome and related diseases.
Autoantibodies recognizing C1D were detected in 7 of 30 patients (23%) with the polymyositis (PM)-scleroderma overlap syndrome; this frequency was similar to the frequencies for the established autoantigens PM-Scl-75c (27%) and PM-Scl-100 (23%).