PRTN3 and rheumatoid arthritis: We analyzed data from 1,221 elderly patients affected by RA; the female-to-male ratio was 3.79, and the mean age was 71.6 ± 5.2 years (23.7% of patients were older than 75); 55.3% of patients were positive for both RF and ACPA, while 77.8% of patients showed at least one of them.