Multivariable analysis in one study showed ACPA-positivity to be an independent risk factor for RA development in individuals with CSA (hazard ratio (HR) = 5.1; 2.0–13.2) and to have a 50–67% PPV (RF-negative/RF-positive) for RA development within 2 years [125]. This evidence concerns the gene PRTN3 and rheumatoid arthritis.