Individuals suffering from leukocyte adhesion deficiency, or LAD, develop frequent bacterial infections, including periodontitis, a severe form of gum disease. Because of the dealing with this devastating oral disease, individuals with LAD often lose their permanent teeth at an early age.
Now, a new study from researchers from the University of Pennsylvania School of Dental Medicine – in conjuncture with the National Institutes of Health – has found a new method of reversing the inflammation and bone loss caused by periodontitis that leads to tooth loss.
The results of this study were published in the journal Science Translation Medicine.
While rare, leukocyte adhesion deficiency can be life-threatening for those suffering from the disease. Individuals can succumb to bacterial infections because their immune systems don’t posses a necessary molecule needed by immune cells – specifically neutrophils – to deal with the site of an infection.
Researchers once believed that LAD patients developed severe periodontitis due to the inability of neutrophils to move from the bloodstream into infected gum tissue. It was therefore thought that harmful oral bacteria was left unchecked and allowed to thrive in the gums.
This new study challenges this long-held belief.
Researchers discovered that bone loss and gum disease continued unabated even after LAD patients were given antibiotics or underwent plaque removal. While LAD patients did not have neutrophils present in their gum tissue as expected, they did possess the molecule in the bloodstream. Upon closer examination, however, researchers discovered that LAD patients involved in the study had high levels of bacteria on the surface of their teeth but bacteria levels that were normal inside their gum tissue.
This marks a very different type of periodontitis than what researchers see in otherwise healthy patients, where neutrophils can actually cause periodontitis to develop by being too prevalent in the gums.
To determine the unique nature of periodontitis among LAD patients, researchers studied the proteins and genes related to the immune system found in these patients. When contrasted to individuals with gingivitis or periodontitis who were otherwise healthy, one particular molecule stood out to researchers: individuals with LAD had extremely high levels of IL-17 and IL-17 mRNA in their gum tissue.
IL-17 acts as a feedback loop for the body’s immune system. When the loop senses that a tissue contain low levels of neutrophil, levels of IL-17 increase, which encourages increased neutrophil production and migration from the bloodstream to the gums. However, since LAD patients’ neutrophils cannot cross into gum tissue, the loop malfunctions, causing increased inflammation.
Not only can IL-17 lead to inflammation, the molecule can also cause osteoclasts, cells that erode away bone structure, in this case teeth.
To treat this condition, researchers intend to test drugs that help to inhibit IL-17 activity in the body – which are already used to treat patients with rheumatoid arthritis and psoriasis – to determine whether these compounds could also be used to treat LAD patients with periodontitis.
The work treating LAD patients with periodontitis just serves to highlight the remarkable breakthroughs researchers continue to make in the field of oral health.
Over the last 20 years, few branches of science have made the kind of advancements as dentistry, and the future continues to look equally bright for the field. Research currently under study ranges from developing compounds that eliminate harmful bacteria in the mouth that causes gum disease and tooth decay to allowing humans to mimic alligators by continuing to regrow teeth throughout our lifetime.
What advances science makes next in oral health remains to be seen, but you can feel confident that it will be something worth smiling about.