Despite being under constant barrage by the immune system, E. granulosus is able to secrete several molecules that can directly modulate the host’s immune system, induce vigorous serological and cellular immune responses and sustain the infection for long time periods (3,4). The hydatid cyst is unilocular and filled with hydatid fluid (HF), a complex mixture of substances derived from the metabolism of the parasite. To date, the HF represents the major source of metacestode proteins for immunodiagnosis SB431542 cell line or vaccine research (4,5). Although distinct antigens and IgG subclasses are good markers

for the diagnostic detection of E. granulosus infection, they demonstrate inadequate performance for the serological assessment of

active vs. inactive forms of CE (6). As the response to surgical and pharmacological treatments is unpredictable for the individual CE case, a constant medical supervision and regular monitoring of imaging findings and serological responses are entailed. In humans, ultrasound (relying on direct visualisation of the parasitic cyst) and serology (parasite-specific serum antibody detection) are the two tests conventionally employed to assess the outcome of infection after treatment (7). As antibodies selleck kinase inhibitor to most major E. granulosus antigens may persist in patients’ sera for several years after treatment, the identification of appropriate single parasite antigens that directly correlate with infection conditions seems an interesting approach for assessing whether the disease will progress or regress (8,9). Proteomic analysis linked to immunological characteristics of respective

antigens may yield improved to investigate the host–parasite relationship in view of metacestode viability or decay. Previous studies have shown that proteomic analysis can be useful for such an approach to identify proteins from hydatid fluid and protoscoleces (10,11). In this study, using an immunoproteomic analysis, we have compared sera from patients with active vs. inactive status of disease, aiming to identify new potential immunological markers involved in the development of CE. Two-dimensional gel electrophoresis (2-DE) of sheep HF (SHF), followed by immunoblot VAV2 (IB) analysis with sera from patients with distinct phases of the disease, enabled us to identify by mass spectrometry, among the proteins present in the HF, heat shock protein 20 (HSP20) as a potential marker of CE activity. We developed an IB assay to highlight the presence of IgG specific to HSP20 in serum from 95 patients with CE, grouped according to the status of disease and cyst type. Finally, we assessed by IB the IgG response to HSP20 during a long-term follow-up in 20 patients pharmacologically and surgically treated. Our observations suggested that antibodies specific to HSP20 might be a potential biomarker for monitoring therapy of CE.