IGA RHEUMATOID-FACTOR IN THE SERA AND SALIVA OF PATIENTS WITH RHEUMATOID-ARTHRITIS AND SJOGRENS SYNDROME

With a sensitive radioimmunoassay we have found elevated IgA rheumatoid factor (IgA-RF) levels in the sera of patients with rheumatoid arthritis, Sjogren's syndrome and systemic lupus erythematosus. The IgA-RF showed a pattern of reaction with hman 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 Sjogren's syndrome.