Can genetic testing help diagnose cannabinoid hyperemesis syndrome?
This article by Lauren Wilson originally appeared on Weedmaps and appears here with her permission.
As awareness of cannabinoid hyperemesis syndrome (CHS) spreads, both among physicians and patients, we collectively become increasingly able to identify a disease that has historically been difficult to diagnose. After all, it seems counterintuitive that cannabis can cause many of the symptoms that it is used to treat.
Researchers are taking our current understanding of this serious and often debilitating disease even further by trying to identify genetic markers that could be used to more easily diagnose CHS. This could potentially prevent those who are vulnerable from developing it in the first place.
Below, find out how CHS is linked to genetics and what the medical world is doing to combat the onset of cannabis-related illness.
What is cannabinoid hyperemesis syndrome?
Still little known or fully understood, cannabinoid hyperemesis syndrome is a condition characterized by a strong and often persistent sensitivity to THC – and possibly other cannabinoids. CHS causes continuous abdominal pain, cramping, nausea, and vomiting when using cannabis.
What causes CHS?
Although our understanding of the disease is still developing, CHS appears to occur most often in people who regularly use high potency cannabis and cannabis products for long periods of time. What happens in the body is intense, long-term stimulation of the endocannabinoid system (ECS), as well as other receptors and systems outside of the ECS.
While medical science is still striving to uncover the most complex and nuanced factors contributing to CHS, according to Dr Ethan Russo, a renowned pioneer in cannabis research, it might be fair to say that CHS no It is not so much a functional gastrointestinal disorder as a “manifestation of an interaction between genes and the environment in a rare genetic disease unmasked by excessive exposure to THC”.
What doesn’t cause CHS? Pesticides.
Dr Russo thinks it’s important to dispel the myth that CHS is caused by pesticides or neem oil used in growing plants. “It just doesn’t hold water as an explanation,” Dr Russo said. âThere are more pesticides in use today than when CHS was first discovered, and the reactions to pesticides are very different from what we see with CHS. Plus, synthetic cannabinoids, which are quite potent, have been shown to induce CHS – and while they’re not pure, they don’t contain pesticides.
The difficulty and high cost of diagnosing CHS
The main symptoms of CHS – cyclic abdominal cramps, nausea, and vomiting – are not unique to this disease, making CHS difficult to diagnose. For this reason, SCH is considered by physicians to be an âexclusion diagnosisâ or a diagnosis made when all other probable causes are excluded.
According to an estimate made in a 2019 study, it took the average emergency department $ 76,920.92 in expenses for related tests to diagnose CHS, while a 2018 article estimated the average cost for a patient of one. CHS emergency visit over $ 4,600.
One thing that makes CHS easier to identify is the habitual or ritualistic behavior of taking hot showers or baths, which patients learn tend to temporarily relieve their symptoms. Another is the relief from topical application of capsaicin cream, which actually works the same physiologically speaking as taking a hot shower or bath.
While hot baths and showers, topical application of capsaicin creams and sometimes even antipsychotic drugs can be used to relieve symptoms, at present the only known cure for CHS is total abstinence. of cannabis.
What is the prevalence of CHS?
Historically, there have been inconsistent reports regarding CHS diagnoses. People with CHS often end up in emergency rooms when cyclic vomiting becomes severe and their health is compromised. Due to the fact that CHS is not widely known or understood in the medical community, coupled with the reality that most physicians receive little or no education or training on the endocannabinoid system, CHS is often misdiagnosed. or labeled as being caused by a cannabis use disorder.
Not only is this disturbing because it unfairly links CHS to drug addiction in the medical community, it also means that we do not have a clear idea of ââthe exact prevalence of CHS among cannabis users and patients. . According to Dr. Russo, CHS is probably much more common than we think.
An epidemiological study, conducted at Bellevue Hospital in New York, interviewed more than 2,000 emergency room patients who presented with cyclic vomiting. They found that over 30% of these patients, who identified themselves as using cannabis for more than 20 days per month and found relief with hot showers, were probably suffering from CHS. When extrapolated to the American population, they estimated that 2.75 million Americans could suffer from CHS.
What do genetics have to do with CHS?
The more we learn about cannabis, cannabinoids, and human physiology, the more our understanding becomes of how plants interact with and impact our bodies.
While there is not a substantial amount of research specifically focused on CHS, thanks to the pioneering work of geneticists and cannabis researchers, we are beginning to paint a preliminary picture of the impact of genetics on the development of CHS.
In partnership with cannabis genetic testing company Endocanna Health, Dr. Russo examined the genetics of 28 patients with cannabis hyperemesis syndrome. What they found were five genetic mutations, called single nucleotide polymorphisms (or SNPs) with plausible causal roles in CHS.
These five genes impact everything from dopamine activity to pain responses, mood regulation, and bowel disorders:
The COMT (catechol-O-methyltransferase) gene provides instructions to make an enzyme that helps break down stimulatory neurotransmitters like dopamine in the brain. When there is a dysfunction of these genes, there can be an excess of dopamine, which can lead to more risky behavior and less inhibition around things like gambling or drug addiction, for example.
According to Dr. Russo, COMT is also associated with depression, rumination of thought, OCD, ADHD and psychosis. Fifty-six percent of the patients with SCH in the study had mutations in this gene.
This gene is involved in the development of TRPV1 receptors, which are activated by a wide variety of physical and chemical stimuli, including those involved in the perception of heat.
Activation of TRPV1 receptors often results in painful and burning sensations, and it is through the interaction with TRPV1 that cannabinoids are able to relieve pain. In Russo’s study, 71% of patients had mutations in this gene, which helps shed light on abdominal pain, bowel problems, and relief from capsaicin creams and hot showers that are common in patients. people with CHS.
This gene provides instructions for making the enzyme CYP2C9, which is involved in the breakdown of steroid hormones and fatty acids. It is also involved in the metabolism of prescription drugs and THC. Forty-six percent of the patients in Russo’s study had mutations in this gene, and he hypothesizes that this mutation could inhibit the breakdown of THC, which would then lead to higher than normal concentrations in the brain. body.
At high concentrations, THC can create a two-phase response, meaning it can create the exact opposite effects that it produces at lower concentrations or doses. It would make sense of the nausea and vomiting that we usually don’t associate with an experience with cannabis.
The DRD2 gene is responsible for creating the dopamine D2 receptor. This receptor is the target of many antipsychotic drugs and exhibited mutations in 60% of patients with CHS in the Russo study. Drugs that target D2 receptors are proemetic, which means they can cause nausea and vomiting, and often affect gut motility, so it makes sense that a dysfunction in the gene encoding this receptor would occur. produced with the CHS.
These receptors are also associated with depression, anxiety, nicotine use, Gilles de la Tourette syndrome, and chronic pain, which could indicate other susceptibilities that patients with CHS may have.
The ABCA1 gene is part of a family of genes responsible for creating proteins that act as vectors for other molecules to cross cell membranes, making them important for basic cell function as well as for our general metabolism and the creation of high density lipoprotein (HDL) cholesterol. .
This gene mutation was present in 68% of patients with SCH in Russo’s study, and while more research is needed, he believes it could indicate that patients with SCH may be more susceptible to coronary heart disease ( CAD), heart attacks, type II diabetes, and Alzheimer’s.
The future of CHS diagnostics
Russo’s study is the first of its kind and the largest study to date focusing specifically on cannabinoid hyperemesis syndrome.
While there is certainly more to be discovered in and around the genetic underpinnings of CHS, this study provides us with several clues and a good battery of tests that can be used to more effectively and cost-effectively screen people for CHS, and to help heavy cannabis. consumers understand if they may be sensitive to CHS. This could save doctors and emergency room patients a lot of time and money.
Companies like Endocanna Health are banking on the future of genetic testing in cannabis, for both patients and consumers. While Dr. Russo was skeptical at first, he understood the potential of this area to really help people. He is now an unpaid scientific advisor at Endocanna and sees promise in genetic testing.
âThis is a relatively new technology, but I have looked at many reports and the correlations seem to be very good. I am convinced that this is useful for a lot of people. I started out as a skeptic, but I think it’s useful technology at this point and should improve as it’s used.