Summary: In Lyme disease, pain, inflammation, and fatigue persist much after the infection has been eradicated. Researchers have been trying to understand why such pain persists and why most commonly used painkillers fail to help. Now, a new study has determined one of the underlying mechanisms of chronic pain due to Lyme disease. This persistent pain appears due to increased activity of fibroblast growth factor receptors (FGFRs). This also means that fibroblast growth factor receptor inhibitors can help reduce peripheral and central nervous system inflammation, thus helping relieve chronic pain in Lyme disease patients.
Bacterium Borrelia burgdorferi causes Lyme disease. It spreads through tick bites. Since it is a bacterial infection, eradicating it through antibiotic therapy is not challenging. However, Lyme disease continues to affect people even when the pathogen has been eradicated.
Lyme disease causes pain, fatigue, and mental distress that continues to affect people for several months and even years after the initial infection has been treated. This occurs because the pathogen causes specific changes in the central and peripheral nervous system.
Chronic pain differs from acute pain not only in its duration. Chronic pain is challenging to treat since it continues to affect individuals even after the disease that caused the initial pain has been treated. It means unlike in acute pain, in chronic pain, it is also essential to reverse the body changes that occurred due to some health disorder or infection.
There are many painkillers, but they only suppress the production of chemicals that cause pain. These drugs help suppress pain sensation, but they are not able to provide complete relief from chronic pain. For complete relief, it is vital to reverse specific body changes that lead to chronic pain.
This is where new biologics excel. These biologics try to reverse body changes, alter pain switches in the body, suppress inflammatory responses, and thus provide lasting relief from chronic pain. The new study published in the Frontiers in Immunology found that fibroblast growth factor receptor inhibitors (FGFRIs) could be quite helpful for Lyme disease-related chronic pain (1).
The Study Finds New Way to Control Pain and Inflammation in Lyme Disease
Previous studies have shown that increased activity of fibroblast growth factor receptors (FGFRs) is one of the significant factors for pain and inflammation in Lyme disease. This increased production occurs in response to Borrelia burgdorferi infection. Interestingly, researchers noticed that even non-viable or dead B. burgdorferi can also cause increased FGFRs production in brain and peripheral nerve tissue nerve cells. It explains why antibiotics can eradicate the infection, but the pain continues.
What is interesting to note is that studies show that non-live B. burgdorferi was an even more potent stimulator of FGFRs. This means that antibiotic therapy can even worsen the pain and inflammation caused by this bacteria. These FGFRs are produced by various cells, including cells that play an important role in brain health, like astrocytes. Once their production has been increased by bacterial toxins, it remains elevated even when the infection has been treated. This explains why those affected by Lyme disease continue experiencing pain much after the initial infection has been treated or causing bacteria eradicated from the body.
Further, researchers started testing FGFR inhibitors. They found that they can significantly reduce inflammation and resulting cell death. Hence, this new class of experimental drugs can help control chronic pain that occurs in Lyme patients. They might also help relieve other disease symptoms like fatigue and mood disorders.
However, they also identified some challenges in introducing this treatment. They found that two different kinds of FGFRIs were needed to manage Lyme disease pain. This is because one type of biologics is more effective for altering pathological changes in peripheral nerves, and other biologics are better for CNS pains.
The Bottom Line
Researchers have identified a novel way of controlling pain, inflammation, and fatigue in Lyme disease patients. They could also understand why the pain and inflammation continue for so long after completely eradicating the bacteria from the body.
Of course, many challenges remain before such treatments become available for clinical use. Nevertheless, these new studies shed light on how chronic pain differs and provides hope for those living with chronic pain.
References
1. Parthasarathy G. Fibroblast growth factor receptor inhibitors mitigate the neuropathogenicity of Borrelia burgdorferi or its remnants ex vivo. Front Immunol [Internet]. 2024 Apr 4 [cited 2024 May 1];15. Available from: https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1327416/full
