P269 Is there a correlation between ethnicity and severity of axial spondyloarthropathy?
Authors: Byravan Swetha , Moorthy Arumugam 
Published: April 2022

Abstract

Background/Aims
Axial spondyloarthropathy (axSpA) is more prevalent in the Caucasian population. This is in part due to genetics; HLA-B27, the main contributing gene, is more prevalent in the Caucasian population, with up to 90% of patients being positive. Incidence is much lower in the Asian and Black population. There are few studies which have compared the relationship between ethnicity and severity of axSpA. Existing studies show that, despite lower incidence of HLA-B27, Black patients actually suffer more severe disease. However, there are few studies investigating the relationship in the Asian population. With Leicester, UK being such a diverse area, we took this opportunity to investigate the correlation between ethnicity and severity of axSpA, including radiographic and extra-articular manifestations.

Methods
Data was collected by retrospective analysis of axSpA patients attending University of Leicester (UHL) axSpA services. Inclusion criteria entailed a diagnosis of axSpA with a documented BASDAI within a year of MRI spine and sacroiliac joints, prior to starting any biological treatment. Exclusion criteria included active infection and/or malignancy, or BASDAI not documented prior to starting biological therapy or within a year of MRI. Data on demographic characteristics, extra-articular manifestations (uveitis, inflammatory back pain, enthesitis, peripheral arthritis, dactylitis, psoriasis, and inflammatory bowel disease), family history, response to NSAIDs, and HLA-B27 status were collected from 149 patients. Relationship with ethnicity was assessed using Pearson’s chi-squared, which we conducted via Statistical Package for the Social Sciences (SPSS) software.

Results
Of the 149 patients, 68% were White Caucasian, 30% Asian and 1% Black. The average age was 43, with 66% male and 34% female. There was no significant relationship between ethnicity and active sacroiliitis (p = 0.926), chronic sacroiliitis (p = 0.218) or axial disease (p = 0.307). 64 Caucasian patients were HLA-B27 positive compared to 27 Asian patients, and no Black patients were positive. Despite this, there was no statistical correlation between ethnicity and HLA-B27 (p = 0.383). Overall, Caucasians consistently had a greater incidence of extra-articular manifestations compared with non-Caucasians. However, no significant p values were observed here or with response to NSAIDs, family history or familial HLA-B27 and BASDAI scores.

Conclusion
From this study, demographics show a larger proportion of Caucasians affected with axSpA compared to other ethnicities, as well as a higher proportion of HLA-B27 positivity, which is in keeping with population studies. It would seem there is a higher incidence of extra-articular manifestations in the White population - however, no statistical significance can be observed. This study was useful to gain further insights into the Asian population but has demonstrated that it is difficult to predict how an axSpA patient will behave based on ethnicity alone. Larger population studies will be needed to further evaluate the relationship between axSpA and ethnicity.

Disclosure
S. Byravan: None. A. Moorthy: None.