AMSTERDAM – Imaging and a positive HLA-B27 test are effective tools for early diagnosis of axial spondyloarthritis in both men and women, according to data from a study of 719 patients with chronic back pain reported at the European Congress of Rheumatology.
Data from previous studies have shown greater severity of axial spondyloarthritis (axSpA) in men, but gender differences at first presentation of the disease have not been well studied, noted Dr. Augusta Ortolan of the University of Padova (Italy) and her colleagues.
Mitchel L. Zoler/MDedge News
Dr. Augusta Ortolan
The researchers analyzed baseline data from 444 women and 275 men in the Spondyloarthritis Caught Early (SPACE) cohort, which included patients with chronic back pain that had lasted 3 months to 2 years. The patients were younger than 45 years at the onset of symptoms.
Overall, 53% of men and 35% of women were diagnosed with axSpA. The duration of symptoms was similar between genders, but the average age at diagnosis was significantly younger for men, compared with women (27 years vs. 30 years; P = .021). A positive HLA-B27 test was more common among men with axSpA than among women with axSpA (80% vs. 60%; P less than .001).
Similarly, the presence of axial spondyloarthritis features on imaging was greater among men with axSpA than women with axSpA (78% vs. 64%; P = .007).
Dr. Ortolan said in an interview that she was somewhat surprised by the findings. “I probably expected to see more differences between male and female patients,” she said. “Although it has been demonstrated that the proportion of men to women is more balanced in axial spondyloarthritis in general [nearly 1:1] as compared to the more advanced stages of the disease [known as ankylosing spondylitis or radiographic axial spondyloarthritis, where the male-to-female ratio is around 3:1], there is a tendency to believe that spondyloarthritis in females is rarer or at least more difficult to detect,” she said. “In fact, the study does not completely contradict this belief as we found that from our chronic back pain population, males are twice as likely to be diagnosed. However, all in all, they do not present so much differently than women,” she noted.
The take home message is for clinicians to examine all features that may lead to a diagnosis of axSpA in patients regardless of gender, Dr. Ortolan said. The study results showing that HLA-B27 and imaging are strongly associated with axSpA diagnosis in both genders in a multivariate analysis, which suggests that clinicians do not need to adopt different diagnostic strategies, she said.
The study findings were the result of a cross-sectional approach that was based on an examination of baseline data, Dr. Ortolan noted. “However, it would be really interesting to see what happens in the long term: Do these gender differences tend to increase? Does the disease have a different long-term impact in men and women? Should we treat them differently? These are open questions that need to be addressed in the future,” she said.
Dr. Ortolan and her colleagues had no relevant disclosures.
Mitchel L. Zoler contributed to this story.
SOURCE: Ortolan A et al. Ann Rheum Dis. 2018;77(Suppl 2):207-8. Abstract OP0323.