Article Text

PDF
Concise report
Recent infections are associated with decreased risk of rheumatoid arthritis: a population-based case-control study
  1. Maria E C Sandberg1,2,
  2. Camilla Bengtsson1,
  3. Lars Klareskog3,
  4. Lars Alfredsson1,
  5. Saedis Saevarsdottir1,3
  1. 1Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
  2. 2Epidemiology and Register Centre South, Skåne University Hospital, Lund, Sweden
  3. 3Rheumatology Unit, Department of Medicine, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden
  1. Correspondence to Dr Maria E C Sandberg, Institute of Environmental Medicine, Box 210, Stockholm 171 71, Sweden; maria.sandberg{at}ki.se

Abstract

Objectives Do recent infections affect the risk of rheumatoid arthritis (RA)?

Methods We used the population-based case-control study EIRA (N=6401) on incident RA and healthy controls, matched for sex, age, calendar period and area of residence. Gastroenteritis, urinary tract infection, genital infection, prostatitis, sinusitis, tonsillitis and pneumonia during the 2 years before inclusion in the study were investigated. Conditional logistic regression was used to calculate OR, adjusting for smoking and socioeconomic status.

Results Infections in the gastrointestinal and urogenital tract before clinical onset were associated with a lowered risk of RA: gastroenteritis (OR=0.71 (95% CI 0.63 to 0.80)), urinary tract infections (OR=0.78 (95% CI 0.68 to 0.90)) and genital infections (OR=0.80 (95% CI 0.64 to 1.00)), while a non-significant association of similar magnitude was observed for the less common prostatitis (OR=0.64 (95% CI 0.38 to 1.08)). In contrast, no associations were observed for sinusitis, tonsillitis or pneumonia.

Conclusions Gastrointestinal and urogenital infections, but not respiratory infections, are associated with a significantly lowered risk of RA. The results indicate that infections in general do not affect the risk for RA, but that certain infections, hypothetically associated with changes in the gut microbiome, could diminish the risk.

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.