This was the conclusion of new research that tested the effects of a protein, called apolipoprotein A-I binding protein (AIBP), in mice with chemotherapy-induced pain.
Should the approach prove to be effective in humans with chemotherapy pain, it could offer an alternative to opioids, which carry the risk of addiction.
A report on the new study — led by the University of California (UC) San Diego in La Jolla — is now published in the journal Cell Reports. It describes how one spinal injection of AIBP alleviated chemotherapy-induced pain in mice — without side effects — for two months.
AIBP binds to a cell surface protein called toll-like receptor 4 (TLR4) that plays a key role in recognising infection and activating the immune system.
The researchers found that AIPB switched off the mice’s TLR4 receptors, effectively preventing and reversing inflammation and cell processes that deal with pain.
Study author Tony Yaksh, professor in the Department of Anesthesiology at UC San Diego School of Medicine said: “What’s so special about our new approach, inhibiting the TLR4 receptor with AIBP, is that it actually modifies the pain processing systems themselves.”
He explains that most pain medications, including opioids, work by “dampening” perception of pain without actually switching off its source, which remains active. In addition, opioids “impart a feeling of pleasure, which leads to their misuse and addiction,” he adds.
He and his colleagues found that AIBP actually blocks “the underlying mechanism that causes pain” — it does not just “mask the symptoms.”
Prof. Yaksh says that around 39 per cent of the 1.7 million people in the U.S. who are diagnosed with cancer every year experience pain as a result of the disease or its treatment.
He estimates that the national burden of morphine or its equivalent for this number of cancer patients — assuming that a typical patient takes around 100 milligrams per day for 12 months — amounts to some 24,000 kilograms per year.
They conclude that their findings reveal a mechanism through which AIBP can alter inflammation of nerve cells and suggest that it may have potential as a treatment for “pre-existing pain states.”
They are already working on alternative ways to administer AIBP systemically. However, they suggest that most people would probably choose to have an injection in their spine “every few months” rather than live with persistent pain.
An important implication is that AIBP could be developed as an alternative to high-dose morphine for those with “unremitting severe pain.” This would reduce use of opioids and the opportunity for misuse.
Prof. Yaksh points out that they are not suggesting that opiates should be dropped as a treatment for persistent pain; “that would be a tragedy,” he notes.
Source: Medical News Today
Reference: Woller, Sarah A. et al, Inhibition of Neuroinflammation by AIBP: Spinal Effects upon Facilitated Pain States, Cell Reports , Volume 23 , Issue 9 , 2667 – 2677
