Clinical and serological study of human alveolar echinococcosis in Slovakia in relation to the outcome of chemotherapy

Alveolar echinococcosis (AE), caused by proliferating metacestodes of the parasitic fox tapeworm Echinococcus multilocularis, is a life-threatening disease in humans. In this study we report four human cases of AE in Slovak Republic with regard to various clinical manifestations and susceptibility to chemotherapy with albendazole or mebendazole. Patients were monitored serologically by ELISA test and Western Blots within 2 - 5 years after initiation of chemotherapy/surgery. Using computerized tomography (CT) we compared morphological changes of the parasitic lesions in the liver during the course of treatment. The parasitic lesions in the CT were manifested as nodular hyperplasia with hyper or hypodense zones and calcified foci within the lesion. In other cases the lesion was visualised as a hypodense poorly-delineated septated focus without calcifications. In the last case, the diagnosis of AE was confirmed only at surgery. Calcified foci found inside the main parasitic lesions were the only abnormality that was detected in two cases and were absent in other two cases. The levels of specific anti-parasitic antibodies followed the pathomorphological changes in the livers. Total IgG levels to Em2+ and EmP antigen declined gradually during the follow-up (1 - 5 years) and disappeared only in the patient receiving radical surgery (cured). In comparison with total IgG, concentration of the IgG4 antibody subclass seemed to correlate more adequately with the outcome of therapy as their levels decreased in improved/stabilised patients, but were elevated in aggravated patients. We showed that, in patients with AE in Slovakia, radical surgery of parasitic foci proved to be the most successful treatment and, in inoperable cases, albendazole and mebendazole were differently effective. Moreover, IgG4 levels rather than total IgG to protoscoleces antigens proved to be more sensitive serological marker of the progress of therapy.