Sir, Polymyositis is an inflammatory myopathy that is related to progressive, proximal, symmetrical muscle weakness, increased concentrations of serum muscle enzymes, an abnormal electromyogram and an abnormal muscle biopsy showing inflammation. Standard drug therapy includes high-dose corticosteroids and immunosuppressive drugs (methotrexate, azathioprine or even cyclophosphamide). Recent data are in favour of the early introduction of a cytotoxic or immune-modulating drug in addition to corticosteroid therapy. In patients with corticosteroid- and immunosuppressive-resistant myositis, management approaches include intravenous high-dose pulse methylprednisolone combined with immunosuppressive drugs, and combination therapy with methotrexate and azathioprine, cyclosporin and/or intravenous immunoglobulin (Ig). Lack of efficacy occurs in some cases. Recent advances in the understanding of the role of cytokines and complement in the pathogenesis of myositis have led to preliminary therapeutic trials of biological agents: etanercept, infliximab and anti-C5 monoclonal antibody [1].

Hyaluronic acid (HA), also known as hyaluronan, is an anionic glycosaminoglycan widely distributed throughout various tissues of the human body. It stands out from other glycosaminoglycans as it lacks sulfation and can attain considerable size: the average human synovial HA molecule weighs about 7 million Dalton (Da), equivalent to roughly 20,000 disaccharide monomers; although some sources report a lower range of 3–4 million Da. In recent years, HA has garnered significant attention in the field of rheumatology due to its involvement in joint lubrication, cartilage maintenance, and modulation of inflammatory and/or immune responses. This review aims to provide a comprehensive overview of HA’s involvement in rheumatology, covering its physiology, pharmacology, therapeutic applications, and potential future directions for enhancing patient outcomes. Nevertheless, the use of HA therapy in rheumatology remains controversial with conflicting evidence regarding its efficacy and safety. In conclusion, HA represents a promising therapeutic option to improve joint function and alleviate inflammation and pain.

The therapeutic response of patients with psoriatic arthritis (PsA) varies greatly and is often unsatisfactory. Accordingly, it is essential to individualise treatment selection to minimise long-term complications. This study aimed to identify factors that might predict treatment response to biological and targeted synthetic disease-modifying antirheumatic drugs (bDMARDs and tsDMARDs) in patients with PsA and to outline their potential application using artificial intelligence (AI). Five electronic databases were screened to identify relevant studies. A random-effects meta-analysis was performed for factors that were investigated in at least four studies. Finally, 37 studies with a total of 17,042 patients were included. The most frequently investigated predictors in these studies were sex, age, C-reactive protein (CRP), the Health Assessment Questionnaire (HAQ), BMI, and disease duration. The meta-analysis revealed that male sex (odds ratio (OR) = 2.188, 95% confidence interval (CI) = 1.912–2.503) and higher baseline CRP (1.537, 1.111–2.125) were associated with greater treatment response. Older age (0.982, 0.975–0.99), higher baseline HAQ score (0.483, 0.336–0.696), higher baseline DAPSA score (0.789, 0.663–0.938), and higher baseline tender joint count (TJC) (0.97, 0.945–0.996) were negatively correlated with the response to therapy. The other factors were not statistically significant but might be of clinical importance in the context of a complex AI test battery. Further studies are needed to validate these findings and identify novel factors that could guide personalised treatment decisions for PsA patients, in particular in developing AI applications. In accordance with the latest medical developments, decision-support tools based on supervised learning algorithms have been proposed as a clinical application of these predictors. Key messages • Given the often unsatisfactory and unpredictable therapeutic response in patients with Psoriatic Arthritis (PsA), treatment selection must be highly individualized.• A systematic literature review was conducted to identify the most reliable predictors of treatment response to biologic and targeted synthetic disease-modifying antirheumatic drugs in PsA patients.• The potential integration of these predictors into AI tools for routine clinical practice is discussed.

Our studies in osteoarthritis provide evidence of a clear effect of acetaminophen on β endorphin levels in plasma (fig 1) compared with rofecoxib 25 mg/day.⁴ Plasma β endorphin levels decreased in 10 patients with osteoarthritis after 1 month of treatment with up to 4 g/day acetaminophen orally (p = 0.017) as well as after 3 months of treatment (p = 0.028). Whereas, there were no changes in the rofecoxib group after 1 month (p = 0.73) and 3 months (p = 1.00), respectively.