Clinical enthesitis in patient with psoriatic arthritis, a systematic literature review with meta-analysis.

Objectives: Enthesitis is considered a hallmark of psoriatic arthritis (PsA). The objective was to assess clinical enthesitis in PsA including its prevalence in different contexts, scores used and consequences of enthesitis.

Methods: A systematic literature review with meta-analysis was conducted in PubMed 2010-2023, focusing on manuscripts involving adult PsA patients and reporting information related to enthesitis. Data collected included the prevalence of clinical enthesitis (i.e., number of patients with at least one enthesitis); scores used: Leeds Enthesitis Index (LEI), MASES, SPARCC; and impact of enthesitis on disease activity, patient-reported outcomes and use of analgesics. Univariate random-effects meta-analysis was applied for pooling percentages and means.

Results: Overall, 212 studies, i.e., 84,262 PsA patients were analyzed. The pooled prevalence of enthesitis in the overall population was 41.6% [95% confidence interval, 37.4-45.8]; with 67.2% [62.0-72.6] in trials and 27.8% [24.5-31.2] in observational studies. The number of enthesitis varied according to the score used, with the lowest observed for the LEI, which was the most widely-used score (63.7%). Patients with enthesitis had higher disease activity and disease burden in comparison with those without enthesitis.

Conclusion: Enthesitis is a frequent manifestation in PsA, concerning close to half the patients, and is more prevalent in trials than in observational studies, reflecting recruitment patterns. The clinical assessment of enthesitis remains challenging, with heterogeneity in the scores used influencing the results: the most used score was the LEI, which also led to the lowest number of enthesitis. Links with patients' quality of life should be further explored.