Increased synovial immunohistochemistry reactivity of TGF-β1 in erosive peripheral psoriatic arthritis.

Background: Immune and non-immune cells contribute to the pathology of chronic arthritis, and they can contribute to tissue remodeling and repair as well as disease pathogenesis. The present research aimed to analyze inflammation and bone destruction/regeneration biomarkers in patients with psoriatic arthritis (PsA), rheumatoid arthritis (RA), osteoarthritis (OA), and ankylosing spondylitis (AS).

Methods: Samples were obtained from the inflamed knee of patients with knee arthritis who had been referred for undergoing arthroscopies. The synovial membrane was processed for pathological description, IHC analysis, and quantification of mRNA expression ratio by qRT-PCR. Serum levels of TGF-β1, IL-23, IL-6, IL-17 A, IL-22, Dkk1, Sclerostin, BMP2, BMP4, Wnt1, and Wnt5a were measured by ELISA. All these data were analyzed and compared with the demographic, clinical, blood tests, and radiological characteristics of the patients.

Results: The synovial membrane samples were obtained from 42 patients for IHC, extraction, and purification of RNA for synovial mRNA expression analysis, and serum for measuring protein levels from 38 patients. IHC reactivity for TGF-β1 in the synovial tissue was higher in patients with psoriatic arthritis (p 0.036) and was positively correlated with IL-17 A (r = 0.389, p = 0.012), and Dkk1 (r = 0.388, p = 0.012). Gene expression of the IL-17 A was higher in PsA patients (p = 0.018) and was positively correlated with Dkk1 (r = 0.424, p = 0.022) and negatively correlated with BMP2 (r = -0.396, p = 0.033) and BMP4 (r = -0.472, p = 0.010). It was observed that IHC reactivity for TGF-β1 was higher in patients with erosive PsA (p = 0.024).

Conclusions: The IHC reactivity of TGF-β1 in synovial tissue was higher in patients with erosive psoriatic arthritis, and TGF-β1 was in relation to higher levels of gene expression of IL-17 A and Dkk1.