Multifaceted Role of Th17 Cells in Psoriatic Disease
Siba P. Raychaudhuri, Smriti K. Raychaudhuri, Debasis Bagchi in Psoriasis and Psoriatic Arthritis, 2017
These findings aligned with similar observations in which IL-17A-deficient mice induced with inflammatory arthritis exhibited greater periosteal bone formation than wild-type mice, while in vitro IL-17A inhibited osteoblast differentiation by upregulating the expression of secreted frizzled-related protein, a Wnt antagonist [48]. These data illustrate that overabundance of IL-17A favors bony erosions and is consistent with observations that IL-17A can drive parathyroid-induced RANKL expression by osteoblasts and osteocytes, with resultant bone loss [49]. In contrast, IL-22 overexpression is associated with bone formation. In vivo expression of IL-23 in mice was demonstrated to result in enthesitis, with CD3+ CD4– CD8– entheseal resident T cells identified that expressed the IL-23 receptor and, upon stimulation, produced IL-22, IL-6, and IL-17 [29]. IL-22 production by these cells drove both entheseal and periosteal bone formation through the activation of osteoblast STAT3, thereby providing a plausible mechanism for enthesophyte and juxta-articular bone formation observed in PsA [29].
Foot and ankle radiology
Maneesh Bhatia in Essentials of Foot and Ankle Surgery, 2021
Anterior ankle impingement occurs as a result of chronic repetitive trauma. This results in enthesophyte formation along the anterior margin of the tibial plafond and the talar neck, leading to restricted dorsiflexion of the ankle joint. MRI demonstrates joint effusion with localised synovitis within the anterior recess of the ankle joint. There is usually associated capsular thickening/scarring demonstrated by thickened synovial lining of the anterior ankle joint.
Role of the IL-23 pathway in the pathogenesis and treatment of enthesitis in psoriatic arthritis
Published in Expert Opinion on Biological Therapy, 2020
Maurizio Rossini, Oscar Massimiliano Epis, Ilaria Tinazzi, Rosa Daniela Grembiale, Annamaria Iagnocco
There are a number of imaging techniques currently available for the diagnosis and assessment of enthesitis including conventional radiography, MRI, and ultrasound imaging. MRI and ultrasound imaging are the preferred imaging options as these are able to detect inflammatory and bone changes in enthesitis at both early and late stages of the disease. More recently, HR-pQCT has been used to evaluate pathological neoformation of the bone to enthesis (enthesophytes) and has identified signs of enthesophyte formation in psoriasis patients without PsA, entheseal bone spurs in PsA, and significant bone-destructive changes in patients with PsA, highlighting the role of entheseal inflammation in PsA. These results emphasize the importance of HR-pQCT in diagnosing SpA.