title: The hygiene theory harnessing helminths and their ova to treat autoimmunity.
abstract: The incidence of autoimmune diseases is increasing in Western countries, possibly due to the improved sanitary conditions and reduced exposure to infections in childhood (the hygiene hypothesis). There is an ongoing debate whether infection prevents or precipitates autoimmune diseases. Various helminths species used in several animal models were shown to limit inflammatory activity in a variety of diseases including inflammatory bowel disease, multiple sclerosis, type 1 diabetes, rheumatoid arthritis, and systemic lupus erythematosus. At present the scientific data is based mostly on experimental animal models; however, there is an increasing body of evidence in a number of clinical trials being conducted. Herein we review several clinical trials evaluating the anti-inflammatory effects of helminths and assessing their association with different autoimmune diseases, including inflammatory bowel disease, multiple sclerosis, and autoimmune liver diseases. We also describe the common pathways by which helminths induce immune modulation and the key changes observed in the host immune system following exposure to helminths. These common pathways include the inhibition of IFN-γ and IL-17 production, promotion of IL-4, IL-10 and TGF-β release, induction of CD4(+) T cell FoxP3(+) expression, and generation of regulatory macrophages, dendritic cells, and B cells. Helminths products are becoming significant candidates for anti-inflammatory agents in this context. However, further research is needed for synthetic analogues of helminths' potent products that mimic the parasite-mediated immunomodulation effect.
authors: Internal Medicine B, Sheba Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Hashomer, Ramat Gan, 52621, Israel.
authors: Dana
authors: D
authors: Ben-Ami Shor
authors: Michal
authors: M
authors: Harel
authors: Rami
authors: R
authors: Eliakim
authors: Yehuda
authors: Y
authors: Shoenfeld
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000947:Antigens, Helminth / Q000276:immunology / Q000627:therapeutic use*; D001327:Autoimmune Diseases / Q000276:immunology / Q000469:parasitology / Q000628:therapy*; D002986:Clinical Trials as Topic; D004195:Disease Models, Animal; D006376:Helminths / Q000276:immunology*; D006801:Humans; D007107:Immune System / Q000469:parasitology; D056747:Immunomodulation; D010063:Ovum / Q000276:immunology; D061147:Therapy with Helminths / Q000379:methods* / Q000639:trends
chemical_list: D000893:Anti-Inflammatory Agents; D000947:Antigens, Helminth