Antinuclear factor in rheumatoid arthritis and related diseases.

Abstract

The 1st group of patients consisted of consecutive in-patients over a 2-year period, the 2nd of patients admitted to a special therapeutic study of early rheumatoid arthritis. ANF was present only in cases of rheumatoid arthritis and related connective tissue diseases. Comparison of ANF positive and negative inpatients with these disorders revealed a statistically significant incidence of unexplained skin rashes, hair change, vasculitis, renal disease, pulmonary disease, leucopenia, positive LE [lupus erythematosus]-cell tests, and hyperglobulinaemia in the ANF positive patients. However, the incidence of pulmonary disease is not significant if past histories of pleurisy or pneumonia and x-ray evidence of old pleurisy are excluded. In the early rheumatoid group there were significant differences between ANF positive and negative patients with respect to hair change, vasculitis, leucopenia, and positive LE-cell tests. Patients with 2 or more positive ANF tests had a higher incidence of vasculitis and positive LE-cell tests than those with only a single positive test. Only one half of the patients found to have LE-cells had ANF in their serum, indicating that the ANF test should not be regarded as merely a more sensitive test for antinuclear antibodies than the LE-cell test. The presence of both ANF and LE-cells in patients tended to be associated with a higher incidence of multisystem involvement than that found in patients with ANF or LE-cells alone. Those with LE-cells only had a higher incidence of subcutaneous nodules and positive tests for rheumatoid factor than those with ANF only. Lastly, determination of immunoglobulin types of ANF showed that IgG correlated best with features suggestive or systemic lupus erythematosus, while patients with IgM had a much lower incidence of such symptoms and signs. The latter group had a high incidence of kerato-conjunctivitis sicca and this was statistically significant when compared with the incidence in the IgG group.