Cort Johnson writes:
We all know the medical profession is poor at providing pain relief in general, but its record with regards to neuropathic or nerve pain is something else indeed.
Despite the fairly large array of drugs physicians use (few of which were developed to reduce nerve pain), no more than 30-40% of nerve pain patients receive as much as 50% relief from the medications doctors provide. Despite research that has uncovered important factors in the production of pain, much clearly remains to be learned.
The production of pathological pain has been shown to be a very complex process. Researchers know, for instance, that damage to the ion channels on nerves, increased levels of excitatory neurotransmitters and reduced activity in the pain inhibition pathways in the brain all play a role.
These authors suggest, though, that a critical component of the pain production pathway – the immune system – has been, if not ignored, then not fully investigated. Studies show that a variety of immune components, from mast cells to macrophages and cytokines to the microglia play a role in pain production.
Recent studies suggest that autoantibodies to the potassium channels – the dorsal root ganglia – key pain processing sites located just outside the spinal cord -are opening up new windows on how pathological pain may be produced. Other than corticosteroids and anti-inflammatories, however, few immune affecting drugs are used to fight pain.
Human immunoglobulin G (IgG) is an immune drug these authors believe may be useful in pain disorders where evidence of increased cytokine production can be found. IgG can be delivered intravenously (IVIg) or subcutaneously (SCIg) and may work by suppressing the immune system.
The fifteen members of this workshop came from Italy, Sweden, Switzerland, Japan, Canada, the U.K., and the U.S. to report on where and when IgG may be useful in treating chronic pain. Some studies were reported on and a good deal of the information derived from case studies.
Symposia Report: Immunoglobulin G for the Treatment of Chronic Pain: Report of an Expert Workshop, by Stefano Tamburin et al in Pain Medicine 2014; 15: 1072–1082