The role of eosinophils in angiostrongyliasis: multiple roles for a versatile cell?

Human infection with the rat lungworm, Angiostrongylus cantonensis, is characterized by a vigorous eosinophil response that gives the disease its name, eosinophilic meningitis. The actual role eosinophils play, both protective and destructive, in this infectious process is still largely a mystery. Research since 2002 has indicated that eosinophils are a multifaceted granulocyte that contributes to a wide range of physiological and pathological processes depending on their location and activation status. This article suggests an expanded role for eosinophils as both classic antiparasitic effector cells and as immune regulatory cells in eosinophilic meningitis caused by Angiostrongylus cantonensis.