Chronic Cannabis Use in Teens Was Linked to Lower B Cell Levels, Hinting at Immune Effects | Research

The takeaway

Adolescents with chronic cannabis use had lower estimated proportions of B cells (immune cells that produce antibodies) compared to non-users, though changes in other immune markers were not significant.

Immunology researchers, pediatricians, and those studying cannabis effects on adolescent health.

Lower B cell proportions found in chronic cannabis-using adolescents

What the researchers found

Using DNA methylation analysis of blood samples, chronic cannabis-using adolescents (n=14) had lower estimated B cell proportions compared to non-users (n=15). An initially observed higher granulocyte proportion was attenuated when controlling for tobacco use. Differences in DNA methylation and gene expression of immune markers (CD4, CD8A, CD19, etc.) were not statistically significant.

Why it matters

This is among the first studies to examine how chronic cannabis use affects the immune system specifically in adolescents, a population where the immune system is still developing. The B cell finding, if confirmed, could have implications for infection susceptibility.

The numbers in context

14 cannabis users vs 15 controls; mean age 16.1; lower B cell proportion in users; 7 immune markers analyzed (CD4, CD8A, CD19, FCGR3A, CD14, FUT4, MPO); granulocyte difference attenuated by tobacco control

How the study worked

Exploratory cross-sectional study comparing DNA methylation and gene expression of immune cell markers in whole blood from 14 adolescent chronic cannabis users (mean age 16.1) versus 15 non-cannabis-using controls.

What this study cannot tell us

Very small sample size (14 vs 15). Exploratory design with multiple comparisons. Cross-sectional. Cannot distinguish cannabis effects from lifestyle or other substance effects. DNA methylation-based cell estimates are indirect.

How to read the evidence

Very small exploratory study using indirect immune measurement. Hypothesis-generating only.

When this study was published

Published in 2024.

The bigger picture

While cannabis's immunomodulatory effects are well-documented in lab studies, evidence of actual immune changes in real-world adolescent users is scarce. This exploratory study opens the door to understanding whether teen cannabis use has functional immune consequences.

Questions still open

Do lower B cell levels in adolescent cannabis users translate to increased infection susceptibility?
Would these immune changes reverse with cannabis cessation?

Common questions

Does teen cannabis use affect the immune system?

This small study found lower levels of B cells (antibody-producing immune cells) in chronic cannabis-using teens, but the sample was too small to draw firm conclusions.

Could cannabis make teens more susceptible to infections?

The B cell finding raises this possibility, but functional immune testing was not done and the sample was very small. Larger studies are needed.

Read the original research

DNA methylation and gene expression of immune cell markers in adolescents with chronic cannabis use: an exploratory study.

BMC psychiatry, 24(1), 676

View on PubMed ↗Publisher’s paper ↗

Citation

Plank, Anne-Christine; Wiedmann, Melina; Kuitunen-Paul, Sören; Wagner, Wolfgang; Perez-Correa, Juan-Felipe; Franzen, Julia; Ioannidis, Charalampos; Mirtschink, Peter; Roessner, Veit; Golub, Yulia. (2024). DNA methylation and gene expression of immune cell markers in adolescents with chronic cannabis use: an exploratory study.. BMC psychiatry, 24(1), 676. https://doi.org/10.1186/s12888-024-06043-0