Why carry out the study?

Few studies have explored the effects of high-titer rheumatoid factor (RF) on clinical outcomes of rheumatoid arthritis (RA) in real-life context.

The present study aimed to evaluate RF titers and their effects on patients with long-standing RA under real-life conditions.

What was learned from the study?

Using a large sample of participants, we found that high-titer RF is associated with worse disease activity, lower physical functionality, increased extra-articular manifestations, and greater use of corticosteroids and biological disease-modifying antirheumatic drugs. Meanwhile, negative and low-titer RF performed similarly.

Dichotomizing RF titers into high (≥ 3 × the upper limit of normality, ULN) and non-high appears more clinically relevant and discriminative than merely using the ULN. This strategy may be useful in the design of further clinical studies and in therapeutic considerations of the management of patients with RA.