The Assessment of SpondyloArthritis international Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general

Abstract

Objective To evaluate new classifi cation criteria for peripheral spondyloarthritis (SpA) in patients with SpA with peripheral manifestations only. Methods In this Assessment of SpondyloArthritis international Society (ASAS) study, two prespecifi ed sets of criteria were compared against the European Spondylarthropathy Study Group (ESSG) and Amor criteria in newly referred consecutive patients with undiagnosed peripheral arthritis, and/or enthesitis, and/ or dactylitis that usually began before 45 years of age. The clinical diagnosis (SpA vs no SpA) made by the ASAS rheumatologist served as reference standard. Results In all, 24 ASAS centres included 266 patients, with a fi nal diagnosis of SpA being made in 66.2%. After adjustments a fi nal set of criteria showed the best balance between sensitivity (77.8%) and specifi city (82.9%): arthritis and/or enthesitis and/or dactylitis plus (A) one or more of the following parameters: psoriasis, infl ammatory bowel disease, preceding infection, human leucocyte antigen B27, uveitis, sacroiliitis on imaging, or (B) two or more other parameters: arthritis, enthesitis, dactylitis, infl ammatory back pain in the past, family history of SpA. The new criteria performed better than modifi ed versions of the ESSG (sensitivity 62.5%, specifi city 81.1%) and the Amor criteria (sensitivity 39.8%, specifi city 97.8%), particularly regarding sensitivity. In the entire ASAS population of 975 patients the combined use of ASAS criteria for axial SpA and ASAS criteria for peripheral SpA also had a better balance (sensitivity 79.5%, specifi city 83.3%) than the modifi ed ESSG (sensitivity 79.1%, specifi city 68.8%) and Amor criteria (sensitivity 67.5%, specifi city 86.7%), respectively. Conclusions The new ASAS classifi cation criteria for peripheral SpA performed well in patients presenting with peripheral arthritis, enthesitis and/or dactylitis.

The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist

“…These strategies were utilized to identify the early inflammatory stage of the disease in patients by focusing on the definition, classification, and diagnostic criteria of IBP and SpA, including the use of magnetic resonance imaging (MRI) for the detection of sacroiliac and vertebral inflammation, as well as the use of HLA-B27 testing. Ultimately, the Assessment of SpondyloArthritis International Society (ASAS) developed concept and classification criteria for axial SpA [11] and then for peripheral SpA [12]. At the same time, we learned about the efficacy of TNF blockers in controlling inflammation, but probably not in suppressing bone proliferation.…”

“…This recent ability to recognize u-SpA patients in this stage, thereby allowing the earlier use of TNF blockers such as etanercept or infliximab, has appeared to result in better clinical responses [69]; this improvement has had a major influence in the development of the concept of axial SpA [9]. The initial strategy was the identification of patients with axial symptoms at risk of AS [9-11]; lately, the a new strategy has evolved in focusing on identification of those with peripheral disease at risk of axial SpA [12]. …”

“…Today, the concept of axial SpA has moved from the non-radiographic sacroiliitis stage of AS to the wider spectrum of SpA, including the axial and peripheral categories [11,12] (Table 3). The ASAS criteria for SpA scope focus on the two most frequent groups of clinical features: the IBP group and the peripheral arthritis, enthesitis, and dactylitis group.…”

“…Thus, the features that link ERA and PsA as SpA are the ones that may be thought to make them incompatible with each other. In contrast, the concept of SpA behind the ASAS axial and peripheral SpA criteria [11,12] reflects the Moll and Wright’s [27] original idea of clinical overlaps between the different diseases. This author’s opinion is that we need common concepts and criteria if we want to keep juvenile and adult onset types of SpA as a disease continuum.…”

“…It seems clear that axial and peripheral SpA classifications have different purposes. While the former [11] is intended to identify the spinal and sacroiliac involvement in the early inflammatory stage of AS, the latter [12] relies on peripheral arthritis, enthesitis, and dactylitis as entry criteria (Table 3). Regarding axial involvement, children and adolescents may have both active sacroiliitis on MRI (Figure 3) and radiographic sacroiliitis grade 2 bilateral or grades 2 or 4 unilateral (Figure 4), but in most cases these events occur in association with peripheral arthritis and enthesitis (Figure 5).…”