One in five people in the world are tattooed. The process involves penetrating ink under the skin using a fine needle. In the specialist journal PNASscientists observed the path of the ink through the lymphatic system, to understand its impact on immune cells.
Tattoo: an inflammatory reaction of the immune system
To do this, they worked with laboratory mice: they tattooed them with inks, manufactured by one of the world’s leading suppliers. Using advanced imaging techniques, they observed the migration of ink in the rodents’ lymphatic vessels. Scientists have found that ink accumulates in certain areas, including the lymph nodes. “We observed that the ink is retained in phagocytic cells, which undergo cell death and induce a significant and long-term inflammatory response, with high levels of pro-inflammatory cytokines in the lymph nodes for up to 2 months after tattooing.”they develop.
Vaccination: effects on the immune response in the event of a tattoo
In the second part of their work, the researchers analyzed the effects of this accumulation in the context of vaccination. When the serum is injected into the tattooed area, scientists noticed a change in immune responses. “We observed a reduced antibody response after vaccination with a messenger ribonucleic acid (mRNA)-based coronavirus 2 (SARS-CoV-2) vaccine, say the scientists. (…) In contrast, we observed an increased response when we vaccinated with the ultraviolet (UV) radiation-inactivated influenza vaccine.”
These differences are linked to the vaccines themselves, which do not act in the same way on the body. “This suggests that tattoo-induced inflammation and the presence of ink pigment particles at the tattoo injection site may interact differently with various vaccine formulations, whose mechanisms of action may differ, potentially influencing antigen presentation, local inflammation, or innate immune activation.”develop the scientists.
Tattoo: effects on immunity to be confirmed in larger studies
The authors point out that further work will be necessary, with trials on groups of humans. “This work represents the most comprehensive study to date regarding the effect of tattoo ink on the immune response and raises serious health concerns associated with the practice of tattooing, they conclude. Our work highlights the need for further research to inform public health policies and regulatory frameworks regarding the safety of tattoo inks.”
