Our findings are in line with other reports, where anti-Pg antibodies could not predict progression to RA.10 12 13 Two of these studies used Pg lysates12 or Pg outer membrane proteins13 to capture anti-Pg antibodies, which may contain citrullinated epitopes due to citrullination by P.PAD,14 leading to false-positive anti-Pg antibody detection in ACPA-positive individuals. Here, PRTN3 is linked to rheumatoid arthritis.