Hygiene hypothesis

Hygiene hypothesis
The hygiene hypothesis links autoimmune disease incidence to the sanitation of an organism’s habitat. According to the hygiene hypothesis, lack of adequate exposure to microorganisms in the formative stages of the immune system during early childhood denies this system an opportunity to develop adequately. The suppressed development of the immune system results in an increased susceptibility to allergic conditions. The mechanism mediating this immune dysfunction is a defect in immune tolerance CITATION WIK16 l 2057 (WIKIPEDIA).
The evidence for the hygiene hypothesis is primarily epidemiologic. Data that shows an increased prevalence of these inflammatory conditions in the developed world that has better hygiene supports the hygiene hypothesis. This hypothesis is especially linked to gastrointestinal conditions such as lymphomas and Crohn’s disease. The higher epidemiologic concentration of multiple sclerosis in the Northern hemisphere has an inverse relationship to the distribution of parasitic infections. Also, infection of this individuals by helminths halts the progression of the disease and increases the number of circulating myelin-recognizing T cells. The parasites are thought to induce the formation of self-recognizing regulatory T cells. The evidence further indicates that exposure to Coxsackie virus in early life is protective while in late life, it triggers autoimmunity.
However, the immune hypothesis has arguments against it. First, there is evidence that exposure to house dust is a risk factor for wheezing in infancy and early life.

This is an autoimmune condition CITATION von04 l 2057 (von Mutius and Eder). These findings are inconsistent with the hygiene hypothesis. Additionally, no significant relationship exists between atopy mediated by TH-2 cells and the autoimmune disorders mediated by the TH1. This evidence suggests that the hygiene hypothesis may have been an oversimplification of a complex process. The TH1 response to infection does not always result in a corresponding TH2 cell line proliferation or regulation, as the hygiene hypothesis suggests.

Works Cited
BIBLIOGRAPHY von Mutius, Erika and Waltraud Eder. “Hygiene hypothesis and endotoxin: what is the evidence?” Current opinion in allergy and clinical immunology (2004): 113-117. Print.
WIKIPEDIA. Hygiene hypothesis. 14 November 2016. Web. 1 December 2016.