Patients with newly diagnosed ankylosing spondylitis (AS) are at increased risk for several immune-mediated inflammatory diseases (IMIDs) compared with healthy controls, according to study results published in Arthritis Research & Therapy.
Investigators abstracted claims data filed in 2003 through 2012 from the Taiwanese National Health Insurance Research Database. Claims data were used to identify patients who were newly diagnosed with AS and required medical therapy between 2006 and 2012. Patients with AS were then matched 1:10 with a randomly selected control group by age, sex, and index date. Hazard ratios (HRs) for each IMID were calculated after adjusting for age, sex, comorbidities, medication use, and number of hospital visits during follow-up. Patients who developed IMIDs more than 3 months after the index date were considered to have incident IMIDs.
The study cohort comprised 30,911 patients with newly diagnosed AS and 309,110 healthy controls; mean age was 42±17 years for both groups, and 62.9% were men.
Compared with healthy controls, patients with AS were at significantly increased risk for acute anterior uveitis (HR, 10.98; 95% CI, 9.10-13.25), psoriasis (HR, 1.41; 95% CI, 1.01-1.96), thromboangiitis obliterans (HR, 16.62; 95% CI, 2.78-99.52), Behcet disease (HR, 26.20; 95% CI, 6.27-109.45), and sarcoidosis (HR, 6.09; 95% CI, 2.38-15.58). However, a decreased risk for rheumatoid arthritis (HR, 0.46; 95% CI, 0.33-0.65) was observed in the cohort of patients with AS compared with the cohort with healthy controls.
No significant differences between the patient group and the control group were observed in risk for Sjogren syndrome, Crohn disease, ulcerative colitis, systemic lupus erythematosus, systemic sclerosis, dermatomyositis, polymyositis, pemphigus, or vitiligo.
These data elucidate the differential risk for certain IMIDs among patients with AS compared with healthy controls. Investigators noted that certain clinical factors, including smoking history and family history, were not available through claims data.
They concluded, “These significant associations indicate potential shared or distinct genetic, pathogenic and clinical relationships between AS and these IMIDs and also suggest that physicians should survey symptoms and signs related to the positively correlated IMIDs when managing patients [with AS].”
Chen H-H, Chao W-C, Chen Y-H, et al. Risk of immune-mediated inflammatory diseases in newly diagnosed ankylosing spondylitis patients: a population-based matched cohort study. Arthritis Res Ther. 2019;21(1):196.