Antibody to stratum corneum (antikeratin antibody) and antiperinuclear factor: markers for progressive rheumatoid arthritis.

The purpose of this study was to examine the relationship between circulating antibodies to stratum corneum (AKA) and antiperinuclear factors (APF) on one hand, and the x-ray progression of joint damage in chronic poly/oligoarthritis on the other hand. The analysis involved 133 patients with either rheumatoid or nonspecific arthritis derived from a cohort of 442 patients with recent onset arthritis. The patients were followed up for eight years with regular clinical, laboratory, and radiological evaluations. Radiographic evidence of joint destruction was quantitated by a radiographic index based on the Larsen grading. AKA and APF were detected, either at entry or at follow-up, in 26 and 54 patients, respectively. Seventy-six of the 133 patients had developed erosions. All AKA-positive patients had a rheumatoid factor-positive erosive poly-arthritis. The presence of APF was also associated with a progressive arthritis although four APF-positive patients had a non-erosive disease. Neither AKA nor APF were able to distinguish a particularly severe form of progressive RA.