The Prevalence of MRI-Defined Sacroiliitis and Classification of Spondyloarthritis in Patients with Acute Anterior Uveitis: A Longitudinal Single-Centre Cohort Study

Background: Acute anterior uveitis (AAU) is a relatively common extra-musculoskeletal manifestation of axial spondyloarthritis (axSpA); however, data on the prevalence of active sacroiliitis in patients with AAU are limited. Methods: 102 patients with AAU and 39 healthy subjects (HS) underwent clinical assessment and sacroiliac joint MRI. Patients with absence of active sacroiliitis were reassessed after two years. International Spondyloarthritis Society (ASAS) classification criteria for axSpA (regardless of patient’s age) and expert opinion for definitive diagnosis of axSpA were applied. Results: Although chronic back pain was equally present in both groups, bone marrow edema (BME) in SIJ and BME highly suggestive of axSpA was found in 52 (51%) and in 33 (32%) patients with AAU compared with 11 (28%) and none in HS, respectively. Out of all AAU patients, 41 (40%) patients fulfilled the ASAS classification criteria for axSpA, and 29 (28%) patients were considered highly suggestive of axSpA based on clinical features. Two out of the 55 sacroiliitis-negative patients developed active sacroiliitis at the two-year follow-up. Conclusions: One-third of patients with AAU had active inflammation on SIJ MRI and clinical diagnosis of axSpA. Therefore, patients with AAU, especially those with chronic back pain, should be referred to a rheumatologist, and the examination should be repeated if a new feature of SpA appears.

Intraocular dendritic cells characterize HLA-B27-associated acute anterior uveitis

Uveitis describes a heterogeneous group of inflammatory eye diseases characterized by infiltration of leukocytes into the uveal tissues. Uveitis associated with the HLA haplotype B27 (HLA-B27) is a common subtype of uveitis and a prototypical ocular immune-mediated disease. Local immune mechanisms driving human uveitis are poorly characterized mainly due to the limited available biomaterial and subsequent technical limitations. Here, we provide the first high-resolution characterization of intraocular leukocytes in HLA-B27-positive (n = 4) and -negative (n = 2) anterior uveitis and an infectious endophthalmitis control (n = 1) by combining single-cell RNA-sequencing with flow cytometry and protein analysis. Ocular cell infiltrates consisted primarily of lymphocytes in both subtypes of uveitis and of myeloid cells in infectious endophthalmitis. HLA-B27-positive uveitis exclusively featured a plasmacytoid and classical dendritic cell (cDC) infiltrate. Moreover, cDCs were central in predicted local cell-cell communication. This suggests a unique pattern of ocular leukocyte infiltration in HLA-B27-positive uveitis with relevance to DCs.

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.