Clinical features and IgG subclass distribution of anti-p80 coilin antibodies

We examined the clinical features of patients presenting antinuclear autoantibodies against p80-coilin and the IgG subclass distribution of anti- p80-coilin antibodies. Sera from 365 Japanese patients were analysed. Immunoblotting and indirect immunofluorescence microscopy techniques were used with a polyclonal rabbit antiserum against p80-coilin. Eleven patients with anti-p80-coilin antibodies were found. All the patients were female and nine were in their twenties. None could be diagnosed with differentiated rheumatic disease except for one case of systemic scleroderma and another of Sjögren's syndrome. Most patients had general fatigue, arthralgia, headaches, dysmenorrhea, lymph node swelling and/or low grade fever such as chronic fatigue syndrome (CFS), and showed low complement. One patient fulfilled the criteria for CFS. All were younger females than those often diagnosed with rheumatic disease in previous reports. Patients' sera had a predominant distribution of subclass IgG(1)anti-p80-coilin antibodies and five sera had concomitant subclass IgG(2). Two rheumatic disease patients had a relatively high titer of IgG(2)anti-p80-coilin antibodies. The IgG(2)subclass of anti-p80-coilin antibodies may be a specific marker for systemic autoimmune disease.