Stratifying the study cohorts according to the treatment scheme, naïve PsA showed similar IHC scores for lining (2.00 ± 0.85) and sublining CD68+ cells (1.71 ± 0.96) compared to naïve Abneg RA patients (1.96 ± 0.79 for lining CD68+ cells, p = 1.00; 1.44 ± 0.80 for sublining CD68+ cells, p = 0.39 respectively). Here, CD68 is linked to rheumatoid arthritis.