RT Journal Article SR Electronic T1 IgA rheumatoid factor in the sera and saliva of patients with rheumatoid arthritis and Sjögren's syndrome. JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 161 OP 165 DO 10.1136/ard.38.2.161 VO 38 IS 2 A1 Dunne, J V A1 Carson, D A A1 Spiegelberg, H L A1 Alspaugh, M A A1 Vaughan, J H YR 1979 UL http://ard.bmj.com/content/38/2/161.abstract AB With a sensitive radioimmunoassay we have found elevated IgA rheumatoid factor (IgA-RF) levels in the sera of patients with rheumatoid arthritis, Sjögren's syndrome, and systemic lupus erythematosus. The IgA--RF showed a pattern of reaction with human IgG subclasses and animal gammaglobulins similar to that of IgM-RF from the same patients. Rheumatoid factors of both classes were shown to be present in saliva of patients with rheumatoid arthritis and Sjögren's syndrome.