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Abstract
Introduction
Ankylosing spondylitis (AS), and carriage of HLA-B27 gene in otherwise healthy individuals, are reportedly associated with increased mortality. We evaluated this hypothesis, using data from both a 35-year AS follow-up study and UK Biobank data.
Methods
In 1985, 363 members of the Swiss AS Patient Society and 806 relatives were screened clinically and then radiographically for AS/axial spondyloarthritis (axSpA). Life expectancy was analysed in 377 axSpA patients having available pelvic radiographs and HLA-B27 status, comparing with matched Swiss population data. Survival in relation to HLA-B27 status in the general population was studied in UK Biobank European-ancestry participants (n=407 480, n=30 419 deaths).
Results
AS patients have increased standardised mortality rate (SMR) compared with the general population (1.37, 95% CI 1.11 to 1.62). This increase was significant for HLA-B27-positive AS (SMR 1.38, 95% CI 1.11 to 1.65). Shortened life expectancy was observed among both HLA-B27-positive AS women (SMR 1.77, 95% CI 1.09 to 2.70) and men (SMR 1.31, 95% CI 1.02 to 1.59). Patients with non-radiographic axSpA (nr-axSpA) had significantly lower SMR: 0.44 (95% CI 0.23 to 0.77), compared with the general population. In the UK Biobank European-ancestry population cohort, HLA-B27 carriage was not significantly associated with any change in mortality (HR 1, 95% CI 0.97 to 1.1, p=0.349, adjusted by sex), in either males (HR 1, 95% CI 0.98 to 1.1, p=0.281) or females (HR 0.96, 95% CI 0.9 to 1, p=0.232), and no increase in vascular disease mortality was observed.
Discussion
AS patients, but not nr-axSpA patients, have a significantly shortened life expectancy. Increased mortality is particularly significant among women with HLA-B27-positive AS. HLA-B27 carriage in the European-ancestry general population does not influence survival, or the risk of death due to vascular disease.
Details
; Mohammad Kazim Khan 2
; Sjef M van der Linden 3
; Winkens, Bjorn 4
; Villiger, Peter M 5
; Baumberger, Heinz 6 ; Hermine van Zandwijk 7
; Khan, Muhammad Asim 8
; Brown, Matthew A 9
1 School of Public Health and Emergency Management, Southern University of Science and Technology, Shenzhen, Guangdong, China; Centre for Genomics and Personalised Health, School of Biomedical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
2 Department of Mathematical Sciences, Kent State University, Kent, Ohio, USA
3 University of Bern, Bern, Switzerland; Department of Internal Medicine, Division of Rheumatology, Maastricht University Medical Centre, Maastricht, The Netherlands
4 Department of Methodology and Statistics, Care and Public Health Research Institute (CAPHRI), University of Maastricht, Maastricht, The Netherlands
5 University of Bern, Bern, Switzerland; Department of Rheumatology and Clinical Immunology, Medical Center Monbijou, Bern, Switzerland
6 Former President of Swiss Ankylosing Spondylitis Patient Society, Flims, Switzerland
7 Rheumatology Research, Mortroux, Belgium
8 Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
9 Genomics England Ltd, London, UK; Department of Medical and Molecular Genetics, King's College London, London, UK