NEW data from a Saudi MRI-based cohort suggest that HLA-B27 status influences the clinical phenotype of axial spondyloarthritis (axSpA), particularly in relation to systemic inflammation and extra-musculoskeletal features, while diagnostic delay and treatment patterns remain largely similar across patient groups.
Axial spondyloarthritis is a chronic inflammatory disease with heterogeneous presentation, and the HLA-B27 genetic marker has long been associated with disease susceptibility and phenotype. However, its clinical relevance varies across populations, and regional data remain limited.
Distinct Clinical Profiles by HLA-B27 Status
In this retrospective cross-sectional study, researchers analysed 84 patients with MRI-confirmed axSpA, all meeting ASAS imaging criteria. Of these, 32 patients were HLA-B27 positive and 52 were negative.
HLA-B27–positive patients were more likely to be male and had higher rates of uveitis and a family history of spondyloarthritis. They also demonstrated significantly higher levels of C-reactive protein, indicating greater systemic inflammation.
These findings support the concept that HLA-B27 positivity is associated with a more defined inflammatory phenotype, including both axial and extra-articular manifestations.
MRI Findings and Diagnostic Delay
Spinal inflammatory involvement on MRI was more frequently observed in HLA-B27–positive patients, although this difference did not reach statistical significance. Importantly, all patients in the cohort had MRI-confirmed disease, underscoring the value of imaging in identifying axSpA across genetic subgroups.
Despite differences in clinical features, diagnostic delay remained substantial in both groups, with no significant difference between HLA-B27–positive and negative patients. This highlights an ongoing challenge in axSpA recognition, even in the era of advanced imaging.
Treatment Patterns Remain Similar
Use of biologic therapies did not differ significantly between the two groups, suggesting that treatment decisions may be driven more by overall disease activity than by HLA-B27 status alone.
Peripheral manifestations were also broadly comparable, reinforcing the complexity and variability of axSpA beyond genetic markers.
Implications for Clinical Practice
The authors conclude that while HLA-B27 positivity is associated with a more inflammatory and characteristic phenotype, it does not appear to influence diagnostic timelines or treatment utilisation in this cohort.
These findings highlight the importance of MRI-based evaluation in axSpA, particularly in populations where HLA-B27 prevalence and expression may differ from Western cohorts. They also emphasise the need for continued efforts to reduce diagnostic delay and improve early identification of disease across all patient groups.
Reference
Alqethami A et al. Clinical phenotype, MRI inflammatory involvement, and treatment patterns in HLA-B27 positive and negative axial spondyloarthritis: a Saudi MRI-based cohort study. BMC Rheumatol. 2026;DOI: 10.1186/s41927-026-00632-0.
Featured image: mantinov
