Acute inflammatory response via neutrophil activation protects against the development of chronic pain, 2022, Parisien et al.

[Trish]

https://www.science.org/doi/10.1126/scitranslmed.abj9954

Beneficial inflammation
Chronic pain can develop from an acute pain state. The mechanisms mediating the transition from acute to chronic pain remain to be elucidated. Here, Parisien et al. focused on the immune system using samples from patients and animal models. Transcriptomic analysis in immune cells from subjects with low back pain showed that neutrophil activation–dependent inflammatory genes were up-regulated in subjects with resolved pain, whereas no changes were observed in patients with persistent pain. In rodents, anti-inflammatory treatments prolonged pain duration and the effect was abolished by neutrophil administration. Last, clinical data showed that the use of anti-inflammatory drugs was associated with increased risk of persistent pain, suggesting that anti-inflammatory treatments might have negative effects on pain duration.

Abstract
The transition from acute to chronic pain is critically important but not well understood. Here, we investigated the pathophysiological mechanisms underlying the transition from acute to chronic low back pain (LBP) and performed transcriptome-wide analysis in peripheral immune cells of 98 participants with acute LBP, followed for 3 months.

Transcriptomic changes were compared between patients whose LBP was resolved at 3 months with those whose LBP persisted. We found thousands of dynamic transcriptional changes over 3 months in LBP participants with resolved pain but none in those with persistent pain. Transient neutrophil-driven up-regulation of inflammatory responses was protective against the transition to chronic pain.

In mouse pain assays, early treatment with a steroid or nonsteroidal anti-inflammatory drug (NSAID) also led to prolonged pain despite being analgesic in the short term; such a prolongation was not observed with other analgesics. Depletion of neutrophils delayed resolution of pain in mice, whereas peripheral injection of neutrophils themselves, or S100A8/A9 proteins normally released by neutrophils, prevented the development of long-lasting pain induced by an anti-inflammatory drug.

Analysis of pain trajectories of human subjects reporting acute back pain in the UK Biobank identified elevated risk of pain persistence for subjects taking NSAIDs. Thus, despite analgesic efficacy at early time points, the management of acute inflammation may be counterproductive for long-term outcomes of LBP sufferers.

Science daily article on this research:
Discovery reveals blocking inflammation may lead to chronic pain
Findings may lead to reconsideration of how we treat acute pain
https://www.sciencedaily.com/releases/2022/05/220512092711.htm

 

[Jonathan Edwards]

So where is the causation to go with these off beat correlations?

The idea that acute pain transforms into chronic pain is drivel as far as I know.
A decent hip replacement takes away pain even if it was there for ten years.
Chronic back pain occurs because discs wear out in almost everyone.

These people should try coping with back pain that keeps you awake every night.

 

[Andy]

Short-term use of ibuprofen may increase chance of chronic pain, study suggests

"Using drugs like ibuprofen and steroids to relieve short-term health problems could increase the chances of developing chronic pain, new research suggests.

The findings from the small study indicate that it could be time to reconsider how pain is treated. Normal recovery from a painful injury involves inflammation – the body’s natural reaction to injury and infection – and new research suggests blocking inflammation with drugs could lead to harder-to-treat issues.

It may be that inflammation has a protective effect, such as preventing acute pain from becoming chronic, and that overly reducing it may be harmful."

https://www.theguardian.com/society...ncrease-chance-of-chronic-pain-study-suggests

 

[Andy]

I’m one of the 28m in Britain who live with chronic pain – where is the plan to help us?

"For some chronic pain conditions, including endometriosis, there is no magic cure. In my case, an extensive surgery in 2020 greatly improved my quality of life. But “chronic” means it will probably always be with me, to a greater or lesser degree, which is hard to accept as a patient. Everything we learn about medicine from childhood is that pain or injury is acute and temporary. Something hurts and then it heals, and taking painkillers is part of that process. But now, a new study has found using drugs such as ibuprofen and steroids to relieve short-term health problems could increase the chances of developing chronic pain in the long term.

This new research joins a growing body of evidence that painkillers could be doing more harm than good. Recent years have seen an increasingly urgent effort among the medical community to manage pain in a different way, by prescribing less and relying on more holistic measures such as physiotherapy and mindfulness. In 2020, the National Institute for Health and Care Excellence (Nice) suggested that patients with chronic primary pain – where the cause for the underlying pain is unclear – should be offered “supervised group exercise programmes, some types of psychological therapy, or acupuncture”."

The rest of the article describes here experience of psychological 'treatment' on the NHS.

"The course was well meaning and, in many ways, radical. It offered the kind of joined-up care that so many suffering from chronic conditions are desperate for, and it was the first time anyone had considered how my pain was affecting my mental health, which it was, greatly. I don’t know how my peers have fared since, but even with the best of intentions, after it ended I struggled to keep up with the relentless positivity towards my condition without the regular check-ins from a team of cheerleading experts.

At first, I felt as if I’d made an uneasy truce with my pain. It hadn’t gone away, but we’d reached a common understanding. But as time passed I settled back into old thinking habits and, if anything, I felt where previously there was a fight in me to improve my pain by seeking answers, there was now a new apathy towards my prognosis. It would be foolish to underestimate the herculean effort it takes on the part of the patient to see their pain in a new light."

https://www.theguardian.com/comment...-pain-support-medication-painkillers-holistic