TWhat if a pronounced TH17 cytokine response in Lyme arthritis were caused by a persistent infection?n?
Immune responses in Lyme arthritis may vary over time, raising questions about their role in disease progression. A pronounced TH17 cytokine response has been linked to both early infection and later autoimmune features.
This raises an important question: could a strong TH17 response in Lyme arthritis reflect a persistent infection rather than autoimmunity alone?
According to a 2017 study in Clinical Infectious Diseases, elevated TH17-associated cytokines may play a beneficial role in early Lyme disease.
“The levels of inflammatory mediators, particularly TH17-associated cytokines, correlated directly with Borrelia burgdorferi IgG antibodies, suggesting a beneficial role for these responses in control of early infection,” report Strle and colleagues.
Shift in Immune Response in Lyme Arthritis
The authors describe a subset of patients with Lyme arthritis who demonstrate elevated TH17 cytokine levels later in the disease course.
These responses were strongly associated with autoantibodies to endothelial cell growth factor (ECGF), apolipoprotein B-100 (apoB-100), and matrix metalloproteinase-10 (MMP-10).
These autoantigens are targets of T- and B-cell responses in approximately 10% to 35% of patients with Lyme arthritis.
The findings suggest that TH17 responses may shift toward an autoimmune phenotype in patients with antibiotic-refractory Lyme arthritis.
Could Persistent Infection Play a Role?
The study raises an important clinical question: what if a pronounced TH17 response reflects ongoing infection rather than autoimmunity alone?
If persistent infection contributes to immune activation, treatment decisions may differ. Immunomodulatory therapy without addressing infection could be problematic.
Clinical Implications
These findings highlight the complexity of Lyme arthritis and the challenge of distinguishing immune-mediated disease from infection-driven inflammation.
Clinicians may consider evaluating for ongoing infection before initiating immunosuppressive therapies in patients with persistent symptoms.
Patients may benefit from review of Lyme disease symptoms, understanding testing limitations, and consideration of coinfections in complex cases.
For more on this topic, see: How to distinguish autoimmune joint disease from persistent infection.
References
- Strle K et al. TH17 cytokine responses in Lyme disease. Clin Infect Dis. 2017.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
