Factors affecting disease manifestation of toxocarosis in humans: Genetics and environment

摘要: Toxocara canis is regarded as the main cause of human toxocarosis but relative contribution T. cati probably underestimated; serological and other diagnostic methods used in most studies this zoonotic disease do not distinguish between two parasites. The definitive hosts for are caniidae. Pups generally have higher infection rates than adult animals a major source eggs environment. Humans usually acquire by accidental ingestion embryonated or encapsulated larvae from environment contaminated food, such infections may lead to visceral larva migrans (VLM), ocular (OLM) covert (CT). Although mixed Th1- Th2-mediated immunological response, particularly with high levels IgE eosinophilia observed, underlying mechanisms molecular immunopathogenesis development symptomatic syndromes VLM, OLM, asymptomatic CT largely unclear. Studies indicated that defences against various infectious diseases be highly influenced complex interactions environmental host genetic factors e.g. MHC class I II, also known leucocyte antigen (HLA). spp. associated polarized CD4(+) Th2 response eosinophilia, mediated mainly HLA II molecules. Associations been made pathological severity effects on exposure infection. Recent research suggests Foxp3(+) CD4(+)CD25(+)-expressing T regulatory (Treg) cells play role regulation immunopathology granulomas experimental toxocaral granulomatous hepatitis enhanced expression TGF-β1, which an important factor local survival function Treg observed during invasion mouse small intestine, liver, muscle, brain. Since potential susceptibility loci molecules, considered involved Th2-dominant immunity controlled CD4(+)CD25(+) stimulation through thus provides beneficial severe injuries organs. However, TGF-β1 variant Leu10Pro warrants further elucidation too toxocarosis. Exploration polymorphism, cells, polymorphisms allow insight into influencing syndrome type humans