Parasite Therapy
The Mechanisms Behind the Hygiene
Hypothesis
Hygiene Hypothesis
 The hygiene hypothesis is that in an
environment where the frequency of
helminthes infection is high the rate of allergy
will be low.
 Basically, the reaction the immune system
has to parasitism acts as a regulatory
mechanism for later allergic type events.
The inverse correlation between type 1 diabetes (yellow) and
low mortality neglected diseases (red)
Mechanisms of Immunity and
Allergies
 This regulation involves a chain of cellular
events starting with the activation of dendritic
cells by the presence of antigens and ends in
the production of helper T cells to protect
against future attacks.
 Autoimmune disorders and allergies result
from a hypersensitivity of T cells to antigens.
How Parasites Influence This
Mechanism
 The immune system response of the host to
parasite infection is first the binding of IgG or
IgE which up regulate the activity of other
immune factors like the dendritic cells.
 The dendritic cells through messenger
molecules like IL-10 initiate production of TH2
cells and Treg cells which are the necessary
products to avoiding hypersensitivity to
allergens.
The Best Parasites For Regulation
 Early research found that, in general,
parasites will lower the prevalence of
allergies. Newer studies and meta-analysis
have shown that certain parasites are better
than others at providing regulatory factors.
Conclusion
 Further research is required though before
we can treat patients with helminthes to cure
allergies.
Another interesting finding
 Recent research has shown that parasite
richness is related to genetic disposition to
autoimmune disease and some links have
been made between the phylogeny of
parasites and human immune factors.
References
Fumagalli, M., Pozzoli, U., Cagliani, R., Comi, G.P., Riva, S., Clerici, M., Bresolin,
N., and Sironi, M. (2009). Parasites represent a major selective force for
interleukin genes and shape the genetic predisposition to autoimmune
conditions. The Journal of Experimental Medicine, 206, 1395-1408.
Leonardi-Bee, J., Pritchard, D., and Britton, J. (2006). Asthma and Current Intestinal
Parasite Infection: Systematic Review and Meta-Analysis. Am J Respir Crit Care
Med, 174, 514-523.
Warner, J.O., Kaliner, M.A., Crisci, C.D., Del Giacco, S., Frew, A.J., Gh, L.,
Maspero, J., Moon, H., Nakagawa, T., Potter, P.C., Rosenwasser, L.J., Singh,
A.B., Valovirta, E., and van Cauwenberge, P. (2006). Allergy Practice Worldwide,
Allergy Clin Immunol Int – J World Allergy Org, 18, 4-10.
Wilson, M.S., Taylor, M.D., Balic, A., Finney, C.A.M., Lamb, J.R., and Maizels, R.M.
(2006). Suppression of allergic airway inflammation by helminth-induced
regulatory T cells. The Journal of Experimental Medicine, 202, 1199-1212.
World Health Organization. (2010, November). Home page. Retrieved March 19,
2011, from http://gamapserver.who.int/mapLibrary/
Yazdanbakhsh, M., Kremsner, P.G., van Ree, R. (2002). Allergy, Parasites, and the
Hygiene Hypothesis. Science’s Compass, 296, 490-494.
Zaccone, P., Fehervari, Z., Phillips, J.M., Dunne, D.W., and Cooke, A. (2006).
Parasitic worms and inflammatory diseases. Parasite Immunology, 28, 515-523.