Evaluation of human cystic echinococcosis before and after surgery and chemotherapy by demonstration of antibodies in serum.

Human cystic echinococcosis (CE), caused by Echinococcus granulosus, is one of the most important and widespread parasitic zoonoses. As one of the problems that can be encountered after treating CE patients is the risk of postsurgical relapses or treatment failure, a long-term clinical and serological follow-up is required to evaluate the success and failure of therapy. Therefore, the aim of the present study was to identify the best diagnostic and prognostic ELISA markers in patients with CE. The cohort comprised 50 patients with symptomatic CE treated with antihelminthic drugs and surgery, who were followed up clinically and radiologically for a mean of 6 years (range 4-8 years). The results clearly indicate that the hydatid specific antibodies of IgE, IgG1 and IgG4 are the most important antibodies for the serological diagnosis of cystic echinococcosis during the active stage of the disease. None of the serum samples from healthy controls gave a non-specific reaction with IgE, IgG1 or IgG4, and a considerably reduced cross-reaction was observed with these antibodies. During post-operative follow-up, the IgM, IgE, IgG1, IgG2 and IgG4 antibody response provided the best correlate of disease activity. The detection of total IgG and IgG3 subclass antibody response for the assessment of post-treatment disease activity among CE patients was insensitive. All patients responded to treatment except 2 women (32 and 36 years old), in whom multiple cysts (12 and 7 cysts) were detected in the liver and lung two years after the first operation. Hence, it can be concluded that the CE-specific antibodies of IgE, IgG1 and IgG4 are the best immunological markers for diagnosis and prognosis of CE patients.