Extra-skeletal manifestations in axial spondyloarthritis are associated with worse clinical outcome despite the use of TNF blocking therapy.

Objective To investigate the prevalence and 4-year incidence of acute anterior uveitis (AAU), inflammatory bowel disease (IBD) and psoriasis, and to explore associations of newly developed extra-skeletal manifestations (ESMs) with clinical disease outcome in a large cohort of axial spondyloarthritis (SpA) patients. Methods All consecutive patients included in the Groningen Leeuwarden Axial SpA (GLAS) cohort between 2004 and 2011 were analysed. History of ESMs at baseline and newly developed ESMs during 4-year follow-up were only recorded when diagnosis by an ophthalmologist, gastroenterologist or dermatologist was present. Results Of the 414 included axial SpA patients, 31.5% had a positive history of one or more ESMs: 24.9% AAU, 9.4% IBD, and 4.4% psoriasis. History of psoriasis was significantly associated with more radiographic damage, especially of the cervical spine. Of the 362 patients with 4-year follow-up data, 15.7% patients developed an ESM: 13.3% patients with AAU, of which 3.6% had a first episode and 9.7% had recurrent AAU, 1.9% developed IBD, and 0.8% developed psoriasis. Patients who newly developed ESMs (without history of ESMs) had worse ASQoL score (mean 10.0 vs. 5.9, p=0.001), larger occiput to wall distance (median 6.3 vs. 2.0, p=0.021) and more limited modified Schober test (mean 12.6 vs. 13.6, p=0.014) after 4 years of follow-up. The majority of patients developing an ESM used anti-TNF therapy. Conclusion History of ESMs was present at baseline in one-third of axial SpA patients. The 4-year incidence of ESMs was relatively low, but patients who developed a new ESM reported worse quality of life.