To study antifilaggrin autoantibodies in patients with early rheumatoid arthritis.
Antifilaggrin autoantibodies were detected by immunoblotting (AFA) and by indirect immunofluorescence ('AKA') in sera from 112 patients with early RA.
At baseline, 'AKA' were detected in 29% and AFA in 32% of sera, whereas after 12 months, they were present in 23% and 26% of sera, respectively. Significant associations between 'AKA', AFA, and rheumatoid factor were found. 'AKA' and AFA titres were significantly higher in patients with susceptibility alleles. No clear relation was observed between 'AKA', AFA, and disease activity but radiological progression tended to be more pronounced in patients having antifilaggrin autoantibodies.
Antifilaggrin autoantibodies, being present in about one third of all new cases of RA, may have a value in early diagnosis. The present data suggest that these autoantibodies also may be a marker of disease severity.