Search

Objective: To evaluate progression from nonradiographic (nr‐) to radiographic axial spondyloarthritis (r‐axSpA) over 5 years in patients with recently diagnosed (≤1 year) axSpA fulfilling the Assessment of SpondyloArthritis international Society (ASAS) classification criteria. Methods: A prospsective, observational study (Patients with Axial Spondyloarthritis: Multi‐Country Registry of Clinical Characteristics) was conducted in rheumatology practices in 29 countries. Baseline and follow‐up radiographs of sacroiliac joints were centrally evaluated by three readers according to the grading system of the modified New York criteria for patients initially classified as nr‐axSpA. Radiographic progression from nr‐axSpA to r‐axSpA was evaluated by Kaplan‐Meier analysis. Cox proportional regression analyses for progression from nr‐axSpA to r‐axSpA were also conducted. Results: Among 2,165 patients with axSpA, 1,612 (74%) were classified as having r‐axSpA (1,050 [65%]) or nr‐axSpA (562 [35%]) by central reading. Of 246 patients with nr‐axSpA (mean [SD] symptom duration: 4.4 [6.2] years) who had at least one follow‐up sacroiliac joint radiograph, progression from nr‐axSpA to r‐axSpA at any follow‐up visit was observed in 40 patients (16%) over 5 years. Mean time to radiographic progression was 2.4 years (ranging from 0.9 to 5.1 years). Progression to r‐axSpA was associated with male sex (hazard ratio [HR] 3.16 [95% CI 1.22–8.17]), fulfillment of the imaging arm of the ASAS classification criteria (HR 6.64 [1.37–32.25]), and good response to nonsteroidal anti‐inflammatory drugs (HR 4.66 [1.23–17.71]). Conclusion: 16% of patients with nr‐axSpA progressed to r‐axSpA within 5 years. Male sex, fulfillment of the imaging arm of the ASAS criteria, and good response to nonsteroidal anti‐inflammatory drugs were predictors of radiographic progression in patients with recently diagnosed axSpA. [ABSTRACT FROM AUTHOR]

Competing Interests: Competing interests: None declared.

Background: The association of the human lymphocyte antigen B27 (HLA-B27) with ankylosing spondylitis (AS), also now called axial spondylarthritis (axSpA), was first described 50 years ago., Objective: This article gives an overview of the available knowledge on the topic., Material and Methods: This is a narrative review based on the experience of the authors., Results: The HLA-B27 is a member of the HLA class I family of genes of the major histocompatibility complex (MHC). The prevalence of HLA-B27 in the central European population is approximately 8 %, i.e., the vast majority of carriers of HLA-B27+ remain healthy. The frequency of HLA-B27 shows a decline from north to south. The HLA-B27 explains only 30 % of the genetic burden of axSpA. The prevalence of the disease correlates with the frequency of HLA-B27 in the population, i.e., there are geographic differences. Approximately 60-90 % of patients with axSpA worldwide are HLA-B27+. Some 200 subtypes of HLA-B27 can be differentiated using the polymerase chain reaction (PCR). In Thailand and Sardinia two subtypes were found that are not associated with axSpA. The physiological function of HLA class I molecules is the defence of the organism against microbes. Microbial peptides are presented to the immune system, which can be specifically attacked by CD8+ T‑cells. Genetic polymorphisms of the enzyme endoplasmic reticulum aminopeptidase 1 (ERAP1), which breaks down peptides in the endoplasmic reticulum, are associated only with HLA-B27+ diseases., Discussion: The pathogenesis of axSpA is unclear but a major hypothesis is that of the arthritogenic peptides. In this it is assumed that potentially pathogenic foreign or autologous peptides can be presented by HLA-B27. If nothing else, HLA-B27 plays an important role in the diagnosis, classification and determination of the severity of axSpA., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)