We compared four enzyme-linked immunosorbent assays (ELISAs) with 172 serum samples from 28 patients with alveolar echinococcosis in different clinical stages according to the World Health Organization-PNM (P = parasitic mass in the liver, N = involvement of neighboring organs, M = metastasis) staging system. The sequential antibody responses against Em (2plus), Em10, and Em18 antigens, and a crude antigen extract were measured in cohorts with resected and unresected lesions. Antibody levels in all assays correlated with the PNM stage before treatment, and the highest correlation was shown for the Em18 assay. The PNM stage did not influence the antibody kinetics, but changes in antibody levels depended on the treatment. In patients after curative surgery, seroreversion in the Em (2plus) ELISA indicated successful resection of lesions in more patients than any other assay, irrespective of the clinical stage. There were no significant differences in the time before assays that use recombinant or purified antigens became unreactive. Antibodies directed against crude antigens were detectable longer than other antibodies in all patient cohorts and stages.

SUMMARYCysticercosis caused by infection with the larval stage of Taenia solium is an important cause of neurological disease worldwide and immunodiagnosis is important for the control and elimination of cysticercosis. In the present study, we established a simple and reliable preparation of immunodiagnostic low-molecular-weight antigens (LMWAgs) from T. solium cyst fluids by a cation-exchange chromatography (CEC). Banding patterns of LMWAgs on SDS-PAGE were different between isolates from Ecuador and China. All cysticercosis patient sera and some echinococcosis patient sera recognized both LMWAgs by enzyme-linked immunosorbent assay (ELISA), but sera from healthy persons were not positive. There was no statistical difference in immunodiagnostic performance of LMWAgs prepared from different geographical isolates. These results indicated that these novel immunodiagnostic antigen preparations could contribute the control and prevention of cysticercosis in endemic areas, especially developing countries.

In this study, we compared the sequential responses of immunoglobulin G (IgG) subclasses to the diagnostic antigen Em18 in sera from patients with alveolar echinococcosis. A total of 225 sera from 36 patients at different clinical stages according to the WHO-PNM staging system were tested. The antibody responses were measured for cohorts with resected and unresected parasitic lesions by enzyme-linked immunosorbent assays (ELISA). Total IgG and, to a lesser extent, IgG4 antibody levels against Em18 correlated with all PNM stages before treatment, whereas levels of IgG2 were low and IgG3 was undetectable. Antibody kinetics, however, depended on the treatment rather than on the PNM stage. For some patients, after curative surgery, IgG1 antibodies dropped below the cutoff earlier than other antibodies, followed by total IgG and IgG4 within 18 months. For some patients with recurrences after surgery, IgG1 and IgG4 reappeared, whereas patients with unresectable lesions but stable disease showed steady declines in the levels of all antibodies, and IgG1 became undetectable in some patients. Additional testing of IgE responses to Em18 showed constantly low levels at all stages and in all cohorts.Alveolar echinococcosis (AE) is caused by the vesicular larval stage of the fox tapeworm Echinococcus multilocularis. The helminth causes dangerous infections characterized by infiltrative growth of the larvae in the livers of natural intermediate hosts such as rodents, and rarely in humans. Metastasis formation may also occur. AE is staged according to the World Health Organization (WHO)-PNM (P, parasitic mass in the liver; N, involvement of neighboring organs; M, metastasis) system (10). Radical resection of parasitic lesions is the preferred treatment (1), but most patients are inoperable at the time of diagnosis (5, 13). In a recent serological study, immunoglobulin G (IgG) antibodies directed against Em18, Em10, and Em2plus antigen compositions showed a close relationship between the clinical status and the treatment of patients with AE (16). In direct comparison, antibodies against Em18 demonstrated the greatest dynamic changeability in all patients, cohorts, and PNM stages, irrespective of the individual treatment. Moreover, Em18 indices had shown the best correlation with the PNM stages prior to treatment. These results prompted us to further investigate the IgG subclass and additionally the IgE response against this diagnostic antigen in patients with either resected or unresectable parasitic lesions. MATERIALS AND METHODSPatients. All patients described in this study were seen at the University Hospital and Medical Center Ulm, Ulm, Germany. A total of 36 patients (225 sera) with a history of hepatic AE and a follow-up period of 1.5 to 6.5 years were included in the study. The patients (age range, 17 to 86 years; mean age, 51.2 years; sex ratio [male to female], 0.57:1) were assigned to different clinical WHO-PNM stages of the disease. All patients had acquired AE in Germany and received benzimidazole therapy. Thirteen p...

Echinococcus vogeli infection in a hunter from the rain forest of French Guiana was confirmed by imaging and mitochondrial DNA sequence analysis. Serologic examination showed typical patterns for both alveolar and cystic echinococcosis. Polycystic echinococcis caused by E. vogeli may be an emerging parasitic disease in Central and South America.

The performance of a rapid and simple immunochromatographic test (ICT) with recombinant Em18 (rEm18) antigen for serological follow-up of Echinococcus multilocularis infection was evaluated by comparison with that of an enzyme-linked immunosorbent assay (ELISA) with rEm18, using serum samples from patients who underwent surgery and/or received antiparasitic chemotherapy. The degree of Em18-band intensity on the ICT correlated highly with the absorbance value obtained by the ELISA. The kinetics of antibody levels obtained by the ICT paralleled those of the ELISA. These data suggest that the ICT has high potential as an easy-to-handle, fast, and reliable follow-up tool to monitor the status of alveolar echinococcosis in different stages.