METHODS AND AGENTS FOR THE DIAGNOSIS AND TREATMENT OF RHEUMATOID ARTHRITIS

摘要

A method for detecting or diagnosing rheumatoid arthritis, and for treating, rheumatoid arthritis based on the presence of auto-antibodies specific for a rheumatoid arthritis (R-A) predictive factor. The R-A predictive factor represents a common epitope which has been identified on both streptokinase (SK) and fibronectin (FN), that is recognized by both a rabbit anti-SK IgG and a human anti-SK IgG isolated from the serum of a rheumatoid arthritis patient. Examination of the sequences of FN and SK indicates a region of homology containing the sequence LTSRPA (SEQ ID NO:1). LTSRPA (SEQ ID NO:1) coupled to a carrier protein reacts with anti-SK antibodies obtained from rabbit or the plasma of patients with rheumatoid arthritis. The human antibodies specific for the LTSRPA (SEQ ID NO:1) epitope demonstrate an increased capacity for activating complement, and a large percentage of these antibodies are sialylated. These studies suggest that the Pm-generated FN 90 kD fragment may react with circulating antibodies originally elicited by streptococcal infections. These immune complexes may play a role in the etiology of rheumatoid arthritis. Diagnostic and therapeutic utilities involving the factors and antibodies thereto are disclosed.