Can you still have rheumatoid arthritis with a negative rheumatoid factor test?

Yes: While the vast majority of patients with RA have a positive rf, a certain percentage do not. Typically, the younger the patient, the better the chance the rf may be negative, depsite a clinical diagnosis of ra.

Most, no! -possible: Most RA patients are rheumatoid factor positive (> 95%). However, some rheumatoid factors are nit the IgM type detectable with standard assays. A more specific test is the ccp antibody. Rember, false positive rf tests are seen in up to %% of the population.