FABP2 and arthropathy: To assess whether gut permeability might change according to disease severity, we stratified patients into inactive (28 joint disease activity score [DAS28] < 2.6), intermediate (2.6 < DAS28 < 5.1), and active disease (DAS28 > 5.1) and analyzed the levels of serum LPS, LBP, and I-FABP within each group.