Ankylosing spondylitis risk spikes with anterior uveitis events
The risk for ankylosing spondylitis among patients increased more than 7-fold following the first episode of anterior uveitis, and more than 17-fold after the second, according to findings published in Arthritis Care and Research.
“Identification of systemic associations in patients with uveitis is important not only to determine the etiology of ocular inflammation and improve visual prognosis but also to improve the outcome of the systemic conditions themselves through a targeted therapeutic approach,” Baek-Lok Oh, MD, of the Armed Forces Capital Hospital, in Seongnam, South Korea, and colleagues wrote. “Ankylosing spondylitis is a chronic inflammatory disease with axial spondyloarthritis whose classification criteria include the presence of anterior uveitis.”
To evaluate the association between anterior uveitis recurrence and ankylosing spondylitis incidence, the researchers reviewed data from the South Korean National Health Insurance Service. Focusing on 10,483 patients with new-onset anterior uveitis between 2004 and 2013, as well as 52,415 matched control cases without any anterior uveitis, the researchers calculated incidence rates of ankylosing spondylitis using the number of uveitis episodes. Incidence rate ratios were determined based on the incidence rate on the control group.
In addition, the researchers identified a subgroup of patients with recurrent uveitis, which was defined as a minimal 120-day interval between consecutive uveitis reports, who were treated with local or systemic steroids, or immune-modifying drugs. This methodology for identifying recurrent episodes was “the main highlight” of the study, the researchers wrote.
“We had to identify whether a patient with uveitis had a 90-day inactive phase without uveitis treatment during sequential visits with a diagnostic code of uveitis,” Oh and colleagues wrote. “Considering that claims with a uveitis diagnostic code could not guarantee an active episode, claims with corresponding diagnostic codes and a prescription code for either steroid or immunosuppressive agents on the same day as the diagnosis were designated active uveitis cases.”
According to the researchers, the incidence rate of ankylosing spondylitis after the first uveitis episode was 121.5 per 100,000 person-years, compared with 16.9 in the control group, for an incidence rate ratio of 7.4 (95% CI, 4.99-10.98). The incidence rate ratio increased to 17.71 (95% CI, 10.44-30.06) after the second uveitis episode. In addition, the incidence rates of ankylosing spondylitis among patients with recurrent uveitis were 284.1 per 100,000 person-years in men and 268.7 in women. Among patients aged younger than 40 years, the incidence rate ratio of the recurrent uveitis group was 46.78 (95% CI, 19.61-111.61).
“The incidence of [ankylosing spondylitis] increased proportionally with the number of episodes of uveitis,” Oh and colleagues wrote. “This study provides a rationale for ancillary workup for possible systemic associations in patients with recurrent uveitis and emphasizes the importance of multidisciplinary collaboration in the diagnosis and management of [ankylosing spondylitis].” – by Jason Laday
Disclosure: The researchers report no relevant financial disclosures.