Infections in pre-RA: a cause or a consequence? Save

Rheumatoid arthritis is known to be associated with a higher risk of infections, and this occurs for multiple reasons: immune dysfunction, systemic inflammation, comorbidities, and treatments.

While infections can be a precipitating factor for the onset of clinical arthritis, the risk of infections in patients during the pre-RA phase remains unclear.

In oral presentation abstract 0535, Porter and colleagues have assessed infection rates in the pre-RA and early RA phases as defined by antibiotics prescription and hospital admissions with an infection main diagnostic code in the UK National database. Newly diagnosed patients from the Scottish Early Rheumatoid Arthritis inception cohort were age and sex matched with controls, and records were screened up to 18 months prior the first prescription of methotrexate and 18 months after.

Half of the patients had at least one infection during the follow-up period and one out of 15 had more than one severe infection. Of interest, the risk of infection was comparable with the controls up to 12 months before onset; with a significant rise at 6 months prior Methotrexate prescription. The infection rate then plateaued for the first 2 years of disease.

While these data emphasize the link between bacterial infections and RA onset, it is unknown whether they represent a cause or a consequence of the immune dysfunction characterizing RA.  As suggested by the authors, low grade systemic inflammation occurring in pre-RA states can lead to a degree of immunosuppression which could explain these observations. More research is warranted to better understand this association.