A team of researchers has highlighted the role of a specific genetic variant in the development of Lyme disease, which may explain why some patients are predisposed to more severe symptoms.
- Lyme disease is an infectious disease caused by a bacterium of the Borrelia burgdorferi sensu lato complex transmitted to humans by the bites of infected ticks. While usually treated with antibiotics, some people develop long-lasting symptoms despite medication.
- According to researchers, this is due to “a specific gene variant directly associated with the disease”, previously unknown in Lyme patients.
- This genetic predisposition means that the body’s anti-inflammatory processes are reduced, and the body produces many antibodies against Borrelia. Result: the bacteria cannot be attacked effectively and the disease sets in over time.
Affecting around 50,000 people each year in France, Lyme borreliosis or Lyme disease is an infectious disease caused by a bacteria of the complex Borrelia burgdorferi sensu lato transmitted to humans through the bites of infected ticks. “An infection does not always lead to illness, and in an outbreak it can usually be treated with antibiotics. However, some of those infected develop persistent symptoms such as fatigue, cognitive impairment or pain despite the antibiotics.”
In search of new treatments, a team of scientists has highlighted the genetic and immunological mechanisms that explain why some patients develop Lyme disease over the long term, and others not.
A specific gene variant that influences the severity of Lyme disease
As part of their work, published in the journals Nature Communications And BMC Infectious Diseases, researchers from the Center for Individualized Infection Medicine (CiiM) in Germany analyzed the genetic patterns of more than 1,000 Lyme disease patients and compared them to those of uninfected people. They were thus able to identify “a specific gene variant directly associated with disease”previously unknown in Lyme patients.
The team then performed various cellular biological and immunological tests to determine the physiological consequences of this genetic predisposition. She first discovered that anti-inflammatory processes in the body were reduced in the presence of this gene variant, meaning that inflammation and Lyme disease symptoms may last longer. Likewise, patients with this genetic particularity produce much fewer antibodies against Borrelia : the bacteria cannot therefore be attacked effectively and the disease sets in over time.
An immune response influenced by genetics
Furthermore, researchers have “identified 34 different genetic loci that are involved in regulating the immune response of Lyme disease patients through messenger substances, called cytokines, and that may also play an important role in other immune-mediated diseases such as allergies”. As a reminder, in genetics, a locus (loci in the plural) designates the location, a precise location, a fixed position, of a particular gene or of a genetic marker on a chromosome.
“The results of our study provided important insights into the genetic and immunological processes that promote the development of Lyme disease”concludes the team of scientists, who hope that this will pave the way for new effective treatments for patients who have long-lasting symptoms.
