TNF and IL-17A dual blockade therapy reduces inflammation and bone proliferation in the axial and peripheral joints. (a) Representative caudal spine sections stained for hematoxylin and eosin (H&E) for rats who were treated with anti-TNF and anti-IL-17A (8C11 and B6-17, n = 4), anti-TNF (8C11, n = 4–5), anti-IL-17A (B6-17, n = 4), or vehicle control (n = 5). (b) Experimentally blinded semi-quantitative scoring (0–4) of inflammation, pannus formation and bone proliferation of histologically stained caudal spine sections showed significant decreases of inflammation for dual blockade (p = 0.036) and anti-TNF (p = 0.039). Pannus formation was significantly reduced for all treatments compared to vehicle control (anti-TNF, p = 0.016; anti-IL17A, p = 0.021; dual blockade, p = 0.037). A numerical decrease of bone proliferation was seen for all treatment modalities compared to vehicle control. (c) Representative ankle sections stained for H&E for the three different treatment modalities and vehicle control. (d) Experimentally blinded semi-quantitative scoring (0–4) of histologically stained ankle sections showed a significant decrease for inflammation for anti-IL17A (p = 0.047) compared to vehicle control. *, p ≤ 0.05.