MADRID – in a large population-based study reported at the European Congress of Rheumatology.
Study investigator Hsin-Hua Chen, MD, and his colleagues at the Taichung (Taiwan) Veterans Hospital found that the adjusted odds ratio for having Sjögren’s syndrome after nontuberculous mycobacteria infection (NTM) was 11.24, with a 95% confidence interval of 2.37-53.24.
The risk for having Sjögren’s syndrome was found to be highest in those aged 40-65 years, versus those older than 65 (aOR, 39.24; P = .09) and in those with no prior history of bronchiectasis (aOR, 37.98; P = .09). Although, in both analyses, the 95% CIs were very wide (3.97-387.75 and 3.83-376.92, respectively), and the P values were not significant.
Dr. Hsin-Hua Chen
Dr. Chen and his colleagues decided to look at the association between tuberculous or nontuberculous mycobacteria with Sjögren’s syndrome for several reasons. First, mycobacterial infections have been linked to the development of autoimmunity. Second, there has been an increased incidence of tuberculosis reported in patients with Sjögren’s syndrome. Third, both Sjögren’s and infection with NTM occurred predominantly in middle-aged women, suggesting a shared potential mechanism.
To investigate a possible association, a matched case-control study was conducted, with data obtained from the Taiwan National Health Insurance Database. There were 5,751 new cases of Sjögren’s syndrome that were identified and validated by at least two qualified rheumatologists and matched to 86,265 controls from the general population according to age, gender, and year of diagnosis. Patients with rheumatoid arthritis and systemic lupus erythematosus were excluded. International Classification of Disease codes were used to identify individuals who had prior TB or NTM infections.
The mean age of patients in both groups was 55 years, and approximately 87% of participants in both groups were female. There was a significant difference in baseline Charlson Comorbidity Index scores between cases and controls (0.5 vs. 0.4; P less than .001), and more cases than controls had bronchiectasis (4.1% vs. 1.3%; P less than .001). Results were adjusted accordingly.
While there was an association between NTM infection and Sjögren’s syndrome, there was no association with tuberculous mycobacteria infection.
Of course, it is not clear if infection with NTM actually causes the condition, and reverse causality cannot be ruled out, Dr. Chen said, so further mechanistic studies would be needed to investigate NTM’s possible role in the development of Sjögren’s syndrome.
Dr. Chen and coauthors had nothing to disclose.