New research of opioid antibodies produced by the immune systems of long-term opioid users was recently presented at the Fall 2020 virtual meeting of the American Chemical Society. The researchers who presented the discovery suggest that these antibodies could be responsible for some of the adverse side effects seen in chronic opioid use.
Cody Wenthur, from the University of Wisconsin–Madison, said:
Opioid use disorder and opioid overdoses continue to be a major epidemic in this country. A relatively new therapeutic approach entering clinical trials is what, in shorthand, we call an opioid vaccine, where the immune system generates a response against the drugs. But for this approach to be successful, we need to identify the people who would benefit from that approach.
First, the researchers had to pinpoint precisely what opioid-related molecules could activate the production of immune antibodies. However, since common opioids such as oxycodone or hydrocodone are too small for the immune system to distinguish, the team had to look at downstream effects when the molecules first enter the bloodstream.
In some cases, specific molecules don’t trigger immune responses until they join more abundant proteins in a process known as haptenization. The new research focused on these opioid-protein conjugates.
The researchers developed a new technique to accurately detect any immune antibodies formed in response to opioid molecules. The study then tested the method in a group of 19 subjects who had taken prescribed opioids for chronic pain. The results showed that 10 of those subjects had anti-opioid antibodies. “This was surprising. We saw antibody responses in people who were taking large doses for as little as six months,” Jillian Kyzer, a researcher on the project, remarked.
The research is still in the beginning stages and is yet to be published in a peer-reviewed journal. Still, the team believes the discovery could help explain why long-term opioid users develop adverse side effects over time.
The antibody discovery helps better understand the efficacy of several opioid vaccines that are currently in development. For years, scientists have been working to develop a vaccine that can stop the high people seek out from opioids. This new research suggests that individuals with high pre-existing opioid antibody levels may respond poorly to forthcoming opioid vaccines.
Kyzer concluded:
The research could also be helpful in identifying efficacy biomarkers for opioid vaccines that are entering clinical trials. If our findings hold up in subsequent research, you would expect individuals with higher levels of these antibodies to be poor candidates for anti-opioid vaccine therapy.
A brief overview of the research is provided in the video below.
