Autoantibodies in normals – the value of predicting rheumatoid arthritis

Excerpt

The cause of rheumatoid arthritis (RA) remains elusive, however, a study demonstrating synovitis in clinically uninflamed joints [1] and several studies reporting the presence of characteristic autoantibodies (IgM rheumatoid factor [RF] and anti-cyclic citrullinated peptide [CCP] antibodies) prior to the appearance of disease manifestations [2‐7] have provided evidence of a preclinical, asymptomatic, phase of the disease. Detection of autoimmune T cells has not yet reached routine diagnostics, but with the development of tetramer and ELISPOT technologies it seems likely that autoantibody detection will serve as the method of choice for the identification of autoimmunity and breaches of tolerance (Fig. 1). In patients with early RA, the frequency of RF is 50–66% and the prevalence of anti-CCP 41–48%, compared to 7–13% and 3–9% respectively in normals [8‐10]. Several recent studies have regenerated interest in the value of positive titres of autoantibodies as markers of rheumatic diseases [11‐15]. Autoantibody positivity prior to symptom development/disease manifestation has also been identified in other autoimmune diseases, such as systemic lupus erythematosus, insulin-dependent diabetes mellitus (IDDM), autoimmune polyendocrine syndromes and celiac disease [11‐20].

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