Immunoglobulin (Ig) subclass-specific antibody responses and isotype-specific recognition of E. multilocularis (Em) and E. granulosus (Eg)
antigens (Ag) were evaluated in both
alveolar echinococcosis (AE) and
cystic echinococcosis (CE). AE patients were divided into 3 groups by clinical and therapeutic criteria according to their actual state of
infection, i.e. elimination of parasite, and regression or progression of disease, CE patients were either before or after surgery, of in continuous
chemotherapy due to parasite persistence. Total
IgE was highly elevated in progressive AE cases (7/11), but not in the cases with eliminated
infection or regression. In AE patients with active disease, EmAg-specific
IgE, total
IgG,
IgG1,
IgG2 and
IgG4 were particularly high. Similarly, in 9 of 30 CE patients, total
IgE was raised above reference values, indicating progressive disease. CE patients" sera antibody cross-reacted with crude EmAg, and detectable Ig levels of the same isotype were also measured by ELISA. In both AE and CE, parasite-specific
antigen recognition was dominated by
IgG1 and
IgG4. In AE patients with progressive disease,
IgG4 distinctively recognized low molecular weight EmAg of Ar 26 kD, 18 kD, 16 kD and 12 kD. As prominent
IgG4 and
IgE responses develop with chronic helminth
infections only, these serological parameters may indicate successful parasite infestation and severe outcome of disease. In summary, analyses of
immunoglobulin isotype responses in AE patients by ELISA in combination with immunoblotting are a useful approach for post-treatment follow-up of patients at risk of developing recrudescent disease.