Santiago F. Gonzalez, Università della Svizzera italiana, Bellinzona, Switzerland, and colleagues have studied how different tattoo inks move through and build up in the lymphatic system using mice.
After tattooing, pigment particles rapidly travel through the lymphatic system and accumulate in draining lymph nodes, where they are engulfed by macrophages (immune cells). These macrophages cannot break down the ink, leading to chronic local inflammation that can persist for months or years and may continuously stress the immune system. The researchers observed two phases of immune response: an acute inflammation shortly after tattooing and a longer-lasting chronic phase associated with immune cell activation in lymph nodes.
In a mouse model, tattooed animals showed a weaker antibody response to an mRNA COVID‑19 vaccine, suggesting ink‑induced changes in immune function; similar effects were seen in human immune cells exposed to ink in vitro.
According to the researchers, the study raises questions about how long‑term retention of tattoo pigments in immune tissues might influence responses to infection and vaccination, and suggests the need for further research into systemic effects of tattoo inks in humans.
- Tattoo ink induces inflammation in the draining lymph node and alters the immune response to vaccination
Arianna Capucetti, Juliana Falivene , Chiara Pizzichetti, Irene Latino, Luca Mazzucchelli, Vivien Schacht, Urs Hauri, Andrea Raimondi, Tommaso Virgilio, Alain Pulfer, Simone Mosole, Llorenç Grau-Roma, Wolfgang Bäumler, Martin Palus, Louis Renner, Daniel Ruzek, Gabrielle Goldman Levy, Milena Foerster, Kamil Chahine, Santiago F. Gonzalez
Proc Natl Acad Sci USA 2025, 122 (48), e2510392122
https://doi.org/10.1073/pnas.2510392122
Also of Interest
Focus: To Tattoo or Not to Tattoo?
Tattooing from a chemical point of view
Clever Picture: Tattooing From a Chemical Point of View
What are tattoo inks? Where in the skin is the tattoo? What happens when a tattoo is removed?
