What autoimmune diseases can a Gastrointestinal (GI) Escherichia coli (E. coli) infection trigger or contribute to?

Autoimmune Diseases Triggered by Gastrointestinal E. coli Infection

Gastrointestinal E. coli infection significantly increases the risk of developing several autoimmune diseases, most notably reactive arthritis, Henoch-Schönlein purpura, systemic lupus erythematosus, Sjögren's syndrome, and IgA nephropathy. 1

Specific Autoimmune Conditions Associated with E. coli Infection

Rheumatologic Conditions

• Reactive arthritis shows a 48.7% increased risk following E. coli infection (HR 1.487) 1
• Systemic lupus erythematosus (SLE) has an 83.8% increased risk after E. coli exposure (HR 1.838) 1
• Sjögren's syndrome demonstrates the highest association with a doubled risk following E. coli infection (HR 2.002) 1

Renal Conditions

• IgA nephropathy risk increases by 61.3% after E. coli infection (HR 1.613) 1
• Henoch-Schönlein purpura shows a 26.5% increased risk (HR 1.265) 1

Gastrointestinal Conditions

• Autoimmune pancreatitis can be triggered by E. coli, specifically through the bacterial protein FliC 2
• Inflammatory bowel disease may be associated with E. coli infection, though the connection is less direct than with other autoimmune conditions 1

Mechanisms of E. coli-Triggered Autoimmunity

Molecular Mimicry

• E. coli proteins share structural similarities with human self-antigens, causing cross-reactive immune responses 3
• Bacterial proteins like FliC can trigger antibody production that cross-reacts with human proteins such as lactoferrin and carbonic anhydrase II 2

Exposure of Nuclear Autoantigens

• E. coli infections can trigger pro-inflammatory cell death programs (pyroptosis, NETosis) that release nuclear contents 4
• These released nuclear materials become available to the immune system for recognition and targeting 4

Bacterial Amyloid/DNA Complexes

• Enteric bacteria like E. coli produce curli amyloid proteins that form complexes with DNA 4
• These curli/DNA complexes can act as danger signals and molecular mimickers that trigger autoimmunity 4

Risk Factors for Developing Autoimmunity After E. coli Infection

• Longer hospital stays for E. coli infection correlate with higher autoimmune disease risk 1
• Multiple E. coli infections increase the likelihood of developing autoimmune conditions 1
• Pre-existing autoimmune conditions elevate the risk of developing additional autoimmune diseases after E. coli infection 1

Clinical Implications

• Patients with severe or recurrent E. coli infections should be monitored for signs of autoimmune diseases 1
• Early antibiotic treatment of E. coli infections may reduce the risk of subsequent autoimmunity 1
• In patients with unexplained autoimmune symptoms, a history of previous E. coli infection should be considered as a potential trigger 1, 4

Diagnostic Considerations

• Autoimmune symptoms may develop months to years after the initial E. coli infection 1
• Testing for autoantibodies may be warranted in patients with history of severe E. coli infections who develop suggestive symptoms 4
• Stool cultures and specific E. coli testing should be considered in patients with new-onset autoimmune conditions to identify potential triggers 5

Common Pitfalls and Caveats

• Not all E. coli infections lead to autoimmunity; host genetic factors likely play an important role in susceptibility 3
• The risk of autoimmunity increases with the severity and frequency of E. coli infections 1
• Distinguishing between infection-triggered autoimmunity and coincidental infection in patients with pre-existing autoimmune conditions can be challenging 4
• The relationship between E. coli and autoimmunity is strongest in pediatric populations where the immune system is still developing 1