The treatment of psoriatic arthritis (PsA) has evolved from NSAIDs and conventional synthetic disease-modifying antirheumatic drugs (DMARDs) to biologics and targeted synthetic DMARDs, enabling more personalized approaches. However, due to disease complexity and comorbidities such as obesity or cardiovascular risk, response to therapy can be variable. Emerging research highlights the importance of understanding both inflammatory and non-inflammatory contributors to disease activity, especially in patients who don’t respond to initial therapies.

Treatment sequencing remains a challenge, particularly in patients who are refractory or intolerant to TNF inhibitors. While newer agents like IL-17, IL-23, and JAK inhibitors show promise—even in treatment-experienced populations—there’s still no clear algorithm for optimal sequencing. Biomarkers and machine learning are under study to predict response, but clinical judgment remains key. Some studies suggest IL-17 inhibitors may work better in patients with obesity or metabolic comorbidities. The role of musculoskeletal ultrasound, lifestyle interventions, and even dual-targeted therapy is expanding, offering potential support for those with persistent symptoms. A more individualized, mechanism-based approach—considering both inflammatory and centralized pain pathways—may help improve outcomes for patients with difficult-to-treat PsA.

Reference: Queiro R, Pinto-Tasende JA, Montilla-Morales C. Navigating Psoriatic Arthritis: Treatment Pathways and Patient-Specific Strategies for Improved Outcomes. Drugs. 2025 Jul;85(7):867-882. doi: 10.1007/s40265-025-02192-y. Epub 2025 May 11. PMID: 40350472; PMCID: PMC12185568.

The diagnosis of psoriatic arthritis (PsA) is frequently delayed due to variable clinical presentations and the lack of specific biomarkers. Genetic susceptibility, environmental triggers, and immune system dysregulation—particularly via the IL-23/Th17 pathway—contribute to disease onset and progression. Biologic and small-molecule therapies targeting TNF-α, IL-17, IL-23, and JAK pathways have significantly improved patient outcomes by reducing inflammation and preventing joint damage.

Mounting evidence also links gut microbiota dysbiosis with PsA development. Studies show that patients with PsA have reduced microbial diversity and lower levels of butyrate-producing bacteria such as Faecalibacterium and Akkermansia, which help maintain gut integrity and immune balance. Dysbiosis may contribute to systemic inflammation and immune dysfunction, potentially triggering or worsening PsA. Microbiota-focused interventions—probiotics, prebiotics, fecal microbiota transplantation (FMT), phage therapy, and dietary changes—are under investigation as adjunctive treatments. While early results are encouraging, more research is needed to determine their safety, efficacy, and role in personalized PsA care.

Reference: Bonomo MG, D'Angelo S, Picerno V, et al. Recent Advances in Gut Microbiota in Psoriatic Arthritis. Nutrients. 2025 Apr 11;17(8):1323. doi: 10.3390/nu17081323. PMID: 40284188; PMCID: PMC12030176.

Researchers explored the role of gut microbiota in patients with psoriatic arthritis (PsA), particularly those presenting with enthesitis and dactylitis, compared to patients with undifferentiated arthritis lacking these features (NO PsA). Using 16S rRNA sequencing, researchers analyzed fecal samples from 9 patients with PsA and 10 patients with NO PsA, excluding those with other defined autoimmune diseases. While standard clinical lab tests could not distinguish between the groups, microbiome analysis revealed notable differences. Specifically, Megasphaera elsdenii was found at levels 10,000 times higher in PsA patients, while the family XIII_AD3011 was more prevalent in the NO PsA group.

The findings suggest that gut microbiota composition is more closely associated with the presence of enthesitis and dactylitis than conventional serum markers. Patients with PsA exhibited greater microbial homogeneity within the group and higher heterogeneity when compared to NO PsA patients. These microbial signatures, particularly Megasphaera elsdenii and Bifidobacterium longum (the latter showing a negative correlation with eosinophils), may serve as potential biomarkers for differentiating PsA from other forms of arthritis. A larger study with deeper biochemical analysis is recommended to validate these preliminary results and further explore the gut-joint axis in inflammatory arthritis.

Reference: Lin CY, Hsu CY, He HR, et al. Gut microbiota differences between psoriatic arthritis and other undifferentiated arthritis: A pilot study. Medicine (Baltimore). 2022 Jul 15;101(28):e29870. doi: 10.1097/MD.0000000000029870. PMID: 35839060; PMCID: PMC11132366.