Periodontitis determining the onset and progression of Huntington's disease: review of the literature

Huntington's disease is a neurodegenerative disorder caused by the expansion of a CAG triplet in the huntingtin gene. It presents with physical, cognitive and psychiatric impairment at different ages in the adult, and has a fatal prognosis. Other than the number of triplet repetitions, there seem to be other factors that explain the onset of this disease at an earlier age. It is well known that neuroinflammation has a key role in neurodegenerative disorders; Huntington's disease is not an exception to that rule. Neuroinflammation exacerbates neuronal damage produced by mutation, by initiating aberrant activation of microglia cell, as well as astrocyte and dendritic cell dysfunction; also compromising the blood-brain barrier and activating the complement cascade. The latter as a direct and indirect effect of the mutation and other stimuli such as chronic infections. In this study, periodontitis is presented as a model of chronic oral infection and a systemic inflammation source. We hypothesize the potential role of periodontitis in Huntington's disease, and the mechanisms by which it contributes to the early onset and progress of the disease. We considered experimental studies, systematic reviews, meta-analyses, published in both Spanish and English, obtained from the PubMed and SciELO databases. There are various mechanisms that generate brain inflammation in these patients; mechanisms of innate immunity being especially prominent. Chronic oral-dental infections, such as periodontal disease, may be an exacerbating factor that adds to the neuroinflammation of Huntington’s disease.