Chronic pain is pervasive in modern society, and chronic low back pain is the most frequently reported chronic pain condition. Current drug treatments for low back pain often target the immune system and include anti-inflammatory drugs (NSAIDs), acetaminophen, and corticosteroids, which have been proven to be minimally effective at best. Additionally, despite the widespread use of NSAIDs in managing chronic low back pain, very little is understood about the molecular mechanisms associated with the transition from acute to chronic pain. The authors of this study evaluated inflammatory pathways at a cellular level to see the connection between the transition from acute to chronic pain and the effect of controlling inflammation with anti-inflammatory medications. After analyzing the differential expression of genes associated with inflammation, the authors determined that suppressing the inflammatory response in the acute phase of injury was more likely to result in chronic pain. The authors replicated their findings in another group of patients suffering chronic temporomandibular disorder. The authors then used rodent models to identify the exact cellular mechanism associated with the transition from acute to chronic pain. Lastly, the authors evaluated a large human cohort to investigate the relationship between low back pain and the use of anti-inflammatory drugs. In their conclusion, the authors state “the beginning of the inflammatory process programs its resolution” and the failure to initiate an appropriate inflammatory response may lead to chronic pain. In their studies of mice, the authors confirm that the acute treatment of inflammation with either steroids, dexamethasone, or nonsteroidals greatly prolonged the resolution of neuropathic, myofascial, and especially inflammatory pain states. Lastly, the large cohort of human subjects demonstrated that individuals treating acute pain with NSAIDs were much more likely to report back pain 2 to 6 years later. The authors state “Our conclusions may have a substantial impact on medical treatment of the most common presenting complaints to healthcare professionals. Specifically, our data suggest that the long-term effects of anti-inflammatory drugs should be further investigated in the treatment of acute low back pain and likely other pain conditions.” It turns out that inflammation following an initial injury plays a key role in recovery and in no way should be suppressed.
Parisien M, et al. Acute inflammatory response via neutrophil activation protects against the development of chronic pain. Sci Transl Med 2022; 14:1-11.
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