Some compelling research on Lyme disease was recently published in the Proceedings of the National Academy of Science. The focus for the research was to try and elucidate the reason that in some patients with Lyme disease they continue to have symptoms despite prompt and appropriate treatment with antibiotics. It turns out to be caused by post-infection inflammation caused by ongoing immune response against part of the bacteria.
Lyme disease is caused by the tick born bacteria Borrelia burgdorferi. This bacterium contains a peptidoglycan (PG) molecule in its cell wall that is released but not degraded when the bacteria die. Since the bacteria invades the skin, brain, joints, and heart, the PG molecules remain in these areas. The immune system “sees” these foreign proteins and tries to eliminate them, but in so doing creates inflammation. The immune inflammation is caused by cytokines especially one called tumor necrosis factor (TNF). The presence of TNF especially in the joints can cause a chronic arthritis, which is the most common post–Lyme complication. But, other less common complications include chronic skin rash, cardiac problems and chronic fatigue. The latter is felt to be due to chronic meningeal inflammation.
Research is ongoing on two fronts. One focus is to try and find a way to degrade the residual PG “debris” and remove it from the body. The other is to try and find a way to stop the post–infection inflammation by schooling the immune system to stop targeting the PG protein.