Could Infections with Parasites Prevent Autoimmune Diseases, Like Asthma and Crohn's Disease?

Abstract

Increasing rates of autoimmune diseases, such as asthma and Crohn’s disease, have become a major concern in industrialized countries. One potential cause for the rising rates of autoimmune diseases in humans, is the disconnected relationship to parasites due to better hygiene. The extensive history between parasites and humans has resulted in the evolution of immunomodulating characteristics in parasites that may prevent the development of autoimmune diseases in humans. Here, I discuss the evolutionary reason for the protective effect against autoimmune diseases provided by parasites, explain the hygiene hypothesis as it relates to parasites, and propose the immunological mechanisms of parasites that might confer protection from autoimmune diseases. I will also give evidence for the protective effect and indicate the current state of helminth therapy and its challenges. While helminth therapy may be an effective treatment and prevention method for autoimmune diseases, much more research needs to be conducted in order to determine the specific mechanisms of action on our immune systems, and how these could be used medically to treat autoimmune diseases.