Compared to ACPA-positive normal weight patients, ACPA-positive patients with obesity had 3.7 mg/L higher CRP levels at baseline and during 5-year follow-up (β3.7, 95% CI 0.96, 6.52; Fig. 2; for raw data, see Supplementary Fig. 2). Here, PRTN3 is linked to obesity due to melanocortin 4 receptor deficiency.