Among those with a positive ACPA, four patients had low-titer ACPA (30.5 ± 4.2 units), though three patients had titers ≥239 units. While patients with autoimmune disease were excluded at study enrollment, 25% (three of 12) with RF or ACPA were later diagnosed with RA, with all RA diagnoses occurring within two years of LD. Here, PRTN3 is linked to rheumatoid arthritis.