Interactions entre le paludisme et les helminthiases: regulation immunitaire, revue de litterature

Dans les zones tropicales et subtropicales, beaucoup de jeunes enfants sont souvent infectes par plusieurs parasites dont ceux du paludisme principalement Plasmodium falciparum et des Helminthes tels que Ascaris lumbricoide , Ankylostomes . Plusieurs etudes menees sur la coinfection dans ces zones montrent l’existence d’une interaction entre ces differentes parasitoses. Les infections a helminthes induisent deux types de reponses (Th2 ou Tr) et des cytokines pro-inflammatoires tandis que les infections a  Plasmodium induisent la reponse Th1 avec des cytokines inflammatoires. Ces differentes reponses sont regulees par une reponse Tr avec des cytokines de regulation. Les helminthes reduisent le processus inflammatoire induit par le paludisme et protege eventuellement contre le paludisme severe. Mots cles: Th1, Th2, Tr, immuno-regulation, co-infection-malaria/helminthiasis English Title: Interactions between malaria and helminthiasis: immune regulation English Abstract In the tropical and subtropical areas, many young children are often infected by several parasites among which are those responsible for malaria, mainly Plasmodium falciparum , and Helminths such as Ascaris lumbricoide and Hookworms . Several studies on the coinfections by two (2) or more parasites in the prevalence zones show the existence of an immunologic interaction between various parasite infections. The infections by helminths lead to two types of immune answers (Th2 and Tr) and type 2 pro-inflammatory cytokines whereas the infections by Plasmodium species lead to mostly Th1-type immune response with type 1 pro-inflammatory cytokines. The Tr type of immune response along with regulation prone cytokines down regulates Th1 and Th2 immune responses. Hence, Helminthic infection reduces the inflammatory process led by the malaria, and eventually protects from severe malaria. Keywords: Th1, Th2, Tr, immunoregulation, co-infection-malaria/helminths