Adolescent exposure to THC may cause immune systems to go up in smoke

When it comes to using marijuana, new research, involving mice and published in the October 2014 issue of the Journal of Leukocyte Biology, suggests that just because you can do it, doesn't mean that you should. That's because a team of Italian scientists have found that using marijuana in adolescence may do serious long-term damage to the immune system. This damage may result in autoimmune diseases and chronic inflammatory diseases, such as multiple sclerosis, inflammatory bowel disease and rheumatoid arthritis in adulthood.

"I hope that the knowledge that early exposure to marijuana is associated with immediate and long-term deleterious effects on the immune system may reach adolescents and their families," said Paola Sacerdote, Ph.D., a researcher involved in the work from the UniversitĂ  degli Studi di Milano in Milano, Italy. "The increased risk of getting sick in adulthood may hopefully be a deterrent for among young individuals."

To make this discovery, scientists injected "adolescent" mice with THC, the main active component of marijuana, for 10 days. This period in the mouse lifecycle corresponded to the adolescence period in humans (approximately ages 12-18). A second group of adolescent mice received only a placebo. At the end of treatments, both groups of animals were left undisturbed for approximately two months, until they reached full adulthood. The activity of the immune system was then evaluated, taking into consideration several important measurements, such as the ability of leukocytes to produce cytokines to mount an antibody response to vaccination or the capacity of macrophage to phagocyte particles. The group of mice treated with THC in adolescence had severe alterations of immune responses in adulthood, characterized by a clear switch toward a pro-inflammatory and cytotoxic phenotype.

"The immune system is characterized by an impressive ability to 'remember' previous exposures and changes during the period of immune system development especially early in life can have important long-term consequences," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. "These studies not only point to adolescence as a key phase of immune system sensitivity, but also highly the dramatic and long-lasting negative effects that a common recreational drug abused by teenagers may have on ."


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More information: Sarah Moretti, Mara Castelli, Silvia Franchi, Maria Augusta Raggi, Laura Mercolini, Michele Protti, Lorenzo Somaini, Alberto E. Panerai, and Paola Sacerdote. Δ9-Tetrahydrocannabinol-induced anti-inflammatory responses in adolescent mice switch to proinflammatory in adulthood. J. Leukoc. Biol. jlb.3HI0713-406RR; DOI: 10.1189/jlb.3HI0713-406RR
Journal information: Journal of Leukocyte Biology

Citation: Adolescent exposure to THC may cause immune systems to go up in smoke (2014, September 30) retrieved 23 August 2019 from https://medicalxpress.com/news/2014-09-adolescent-exposure-thc-immune.html
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Sep 30, 2014
"When it comes to using marijuana, new research, involving mice and published in the October 2014 issue of the Journal of Leukocyte Biology, suggests that just because you can do it, doesn't mean that you should."

Such a biased assumption, typical of the initial mentality behind much cannabis research - usually government funded.

I tried, and failed, to find out what the doses used might have been. Generally, with this type of research, they will inject the mice with the body-mass equivalent of about 1000 high-quality joints at one time, and infer they are getting valid results which can be applied to a human. That is unreasonably absurd, but seems to be the accepted convention normally applied to this research.

Sep 30, 2014
I might add that I recently found this found this quote from a book about drug research:

"Laboratory scientists sometimes joke that the definition of a drug is any substance that, when injected into a rat, produces a journal article. Hundreds of studies have proven that laboratory animals can be taught to self-administer cocaine, even to the point of causing their own death."

I can only imagine how much brilliant insight they derive about human behavior by giving unlimited, pure, (and free) cocaine to a simple minded rat. But they do. In a studies such as this, they never think to include at least one group of rats who have to get a job, earn the money, and then pay for the stuff.

Reality-based drug research is a rare thing indeed.

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