FIGURE 4.

The defect in M2-like polarization leads to an M1-like phenotype. (A) Representative images and frequencies of CD68⁺ iNOS⁺ macrophages detected in HD (n = 6) and in patients with SS (n = 7), SpA (n = 5), RA treated with MTX (n = 4), RA treated with MTX + ETA (n = 7), and RA treated with MTX + ADA or IFX (n = 7) and RA treated with MTX + non-TNFi biologic (n = 3). Scale bar, 10 μm. (B) IRF5 mRNA expression on M2-like macrophages was determined by quantitative real-time PCR (HD n = 5 and RA n = 7). Results are show as box and whiskers (min to max). (C) Spontaneous 6-d cytokine production by M2-like macrophages from HD (n = 6), RA DAS28-CRP ≤ 3.2 (n = 14), and RA DAS28-CRP ≥ 3.2 (n = 13) (27 patients included; 6 were on MTX, 2 on tocilizumab, 1 on rituximab, 3 on abatacept, 7 on ETA, and 8 on ADA). (D) Regression analysis showing a significant positive correlation between monocytes mTNF expression (geometric mean fluorescence intensity [gMFI]) and the ratio iNOS⁺/ARG⁺ in monocyte-derived M2-like macrophages from RA treated with MTX or non-TNF biologics or RA treated with MTX + ETA. Results are shown as mean ± SEM. Mann–Whitney t test, Kruskal–Wallis test with Dunn multiple comparisons, and the two-tailed nonparametric Spearman for correlation *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.