A tattoo is a form of individuality or self-expression among many people. With tattoo markings, people can display their sense of identity or convey a reminder or a memory they have been holding. Unhappy experiences or a career change can force people to have their tattoos removed and laser surgery is the best method to remove tattoos. However, laser surgery is very expensive and may not work on all kinds of tattoos. A new research from France has discovered the key to improve tattoo removal techniques by tapping into a type of immune cell.
An Immune Cell Manages Tattoos
Researchers in France discovered that a type of cell from the immune system is working wonders in managing tattoos on the skin. The cell is called a macrophage that exists in the dermis layer of the skin. Macrophages are derived from monocytes, the largest type of white blood cells that influence adaptive immunity, which devours a number of different elements in the body, such as debris, foreign substances, germs, and even cancer cells.
Macrophages are also attracted to the wound caused by the tattoo needle and devour the tattoo pigment, similar to engulfing an invading microbe. The macrophages that consume the pigment carry it throughout their life cycle that may lead to less or more permanent tattoo results.
The French researchers found that these cells could be used in improving tattoo removal methods available today. They stumbled upon a specific type of skin macrophage in mice with black coats that ingest pigment particles. They studied and worked on that skin macrophage to prove its capability to swallow pigment particles, such as those from a tattoo needle.
First, they genetically engineered some skin macrophages with receptors of diphtheria toxins and then transplanted them to a set of mice. The receptors are designed to kill the cells with diphtheria toxins. Second, the researchers applied green fluorescent ink on the mice's tails and analyzed the sections of the tattooed skin under a microscope, so they can confirm if the macrophages have devoured the pigment particles. Then, they exposed the mice to diphtheria to kill the macrophages.
The researchers were surprised that the ink stayed on the animals for several months, even after other macrophages replaced the cells that initially devoured the particles. The observation suggested that the initial macrophages released the particles upon death and new ones or neighboring ones devoured them since the particles are considered foreign substances to them.
"The fact that macrophages hardly move within the skin explains why the tattoo is pretty stable. Moreover, the pigment particles present in tattoo ink are quite big, and owing to their size they aren't drained into the lymph nodes via the lymphatic vessels. So as soon as they are released by dying macrophages, they remain stuck until another macrophage ingests them," said Dr. Sandrine Henri, the lead author of the study and an immunologist at the Centre d'Immunologie de Marseille-Luminy.
Using the approach as a tattoo removal method, dermatologists can augment laser techniques and temporarily block the pigment-carrying macrophages to completely remove tattoos. According to Dr. Henri, the pigment particle fragments from laser pulses are unlikely to be recaptured by other macrophages in a short period of time. Instead, the fragments are drained into the lymphatic vessels.
An immunologist at the University College London commended the study findings that should be developed further. The results can help remove unwanted tattoos, particularly the small ones in well-defined locations.
The French researchers are continuing their efforts to improve the new approach to reduce potential health risks. Macrophages play an essential role in removing pathogens, improving wound healing, and regenerating skeletal muscles. Ablation or obstruction of these immune cells can impair the processes they support.
Risks and Precautions of Getting Tattoos
Getting a new tattoo has its advantages, such as bragging rights and a sense of pride. But the process may cause health disadvantages. Tattoo application involves pricking the top layer of the skin using one or more needles, which can cause pain and bleeding. According to the Mayo Clinic, the process comes with health risks, such as:
1. Allergic reactions: Tattoo markings require dyes and people may experience allergic reactions to blue, red, green, and yellow dyes. The most common adverse reaction is a skin rash that may persist for years after the tattoo application.
2. Skin infections: The pricking of the skin can cause bleeding and make the area susceptible to bacterial infections.
3. Bloodborne diseases: If the tattoo artist does not follow strict decontamination and sanitary practices, the needles used may potentially carry infected blood. Certain diseases, such as hepatitis B and C, can be transmitted through tattooing.
4. MRI issues: In rare cases, the burning or swelling areas where tattoos have been marked can interfere with MRI scans.
5. Other skin problems: Granuloma or inflammation of a skin area can form around the ink. Raised areas due to overgrowth of scar tissue may also occur after tattooing.
[메디컬리포트=Ralph Chen 기자]