According to a recent study from the Institute of Environmental Medicine in Stockholm, gastrointestinal and urogenital infections lower the risk of rheumatoid arthritis (RA). In the study titled ”Recent infections are associated with decreased risk of rheumatoid arthritis: a population-based case-control study,” recently published in the Annals of the Rheumatic Diseases, researchers found that infections in general do not affect the risk for RA, however, specific infections associated with changes in the gut microbiome may lower the risk.
In their investigation, Dr. Maria E. C. Sandberg from the Institute of Environmental Medicine in Stockholm and colleagues assessed 6,401 individuals a population-based, case-control study called EIRA. Participants included those diagnosed with RA and healthy controls, age and sex matched. Gastroenteritis, urinary tract infection, genital infection, prostatitis, sinusitis, tonsillitis and pneumonia during the 2 years before inclusion in the study were assessed.
The participants were also assessed for prostatitis, antibiotic treatment for sinusitis, tonsillitis/other throat infection, or pneumonia during this time.
Results from logistic regression analysis revealed that gut, urinary tract, and genital infections in the previous 24 months were associated with lowered risk of developing RA by 29%, 22% and 20% respectively. In those participants that had the three types of infections in the previous 24 months, the results revealed a 50% lowered risk for RA. Smoking and socioeconomic status did not impact the results. Recent infection in the previous 12 months was not related to the risk of RA, however, infections in the gut, urinary tract and genital inflammation in the previous 24 months were stronger in the individuals that tested positive for a protein called ACPA, which is associated with the development of RA. Conversely, the results revealed no associations for sinusitis, tonsillitis or pneumonia.
Findings from this study strongly indicate that gastrointestinal and urogenital infections, but not respiratory infections, are associated with a significantly lowered risk of RA. The researchers stated that based on these results, infections in general do not affect the risk for the development of RA, however, specific infections, putatively associated with changes in the gut microbiome, could reduce the risk — a finding that could lead to novel therapeutic options in the future.
The researchers said that their findings “are particularly interesting in light of emerging data implicating that the microbiome in the gut may play a role in rheumatoid arthritis pathogenesis.”