Extra-musculoskeletal manifestations driving the therapeutic decision-making in patients with Spondyloarthritis: a 12-month follow-up prospective cohort study.

Background: The extra-musculoskeletal manifestations (EMMs) such as recurrent acute anterior uveitis (rAAU), psoriasis (Ps), and inflammatory bowel disease (IBD), are related to the Spondyloarthritis (SpA), as well as they are associated with disease activity and poor prognosis. However, there are no data addressing its relevance regarding therapeutic decision-making in clinical practice.

Objective: To evaluate the impact of EMMs to drive the treatment decision-making in patients with SpA in a 12-month follow-up.

Patients and methods: SpA patients, according to the axial and peripheral ASAS classification criteria, as well as CASPAR criteria, with any active EMM, defined as main entry criteria, were included in this longitudinal cohort study. Individuals with a history of any disease or condition that could be associated with some of the studied endpoints, including neoplasms and infectious diseases, were excluded. Specific tools related to each EMM, including Psoriasis Area Severity Index (PASI), ophthalmologic evaluation, according to the Standardization of Uveitis Nomenclature (SUN) criteria, and gut complaints were used at baseline and during the 3-, 6- and 12-month of follow-up as outcomes measures over time. Descriptive and inferential analyses were used appropriately, including Pearson's correlation test, chi-squared test, and ANOVA. P value less than 0.05 was considered as significant.

Results: A total of 560 patients were enrolled, of whom 472 meet the eligibility criteria. The majority (N = 274; 59.6%) had one or more EMM related to SpA umbrella concept. Among the EMM, the one that most influenced therapeutic decision-making was psoriasis (28.5%), followed by uveitis (17.5%) and IBD (5.5%), regardless of musculoskeletal manifestations. Clinical improvement of EMMs outcomes was observed in most patients over 12-month follow-up, especially in those with rAAU and IBD (P < 0.001).

Conclusion: Our results showed that EMMs guided the therapeutic decision-making in half of SpA patients, regardless of musculoskeletal condition, suggesting the inter-disciplinarity among the rheumatologist, ophthalmologist, dermatologist, and gastroenterologist plays a crucial role to manage them.