An update on immunodiagnosis of cystic echinococcosis

Immunological parameters are increasingly investigated as possible markers for the development of cystic echinococcosis. Among the newer immunologic tests for assessing the host–parasite relationship, assay of immunoglobulin isotypes with the use of distinct parasite antigens and detection of Th1/Th2 cytokine expression are an interesting new approach. The findings upon which we have constructed our immunological hypothesis of the host–parasite relationship are: (1) immunoglobulin isotype profiles differ in patients with distinct clinical outcomes of the disease; in particular, antigen B is the antigen of choice to detect specific IgG4, which is the immunoglobulin isotype most clearly associated with the progression of the disease; (2) the isolation and characterisation of recombinant parasite proteins that behave as molecular markers of allergic reactions associated with cystic echinococcosis; (3) Th1/Th2 cell activation is involved in the clinical outcome of Echinococcus granulosus infection and, in particular Th2 response, is associated with susceptibility to the disease, whereas a Th1 response is associated with protective immunity