Improved Serodiagnosis of Cystic Echinococcosis Using the New Recombinant 2B2t Antigen

Abstract

A standardized test for the serodiagnosis of human cystic echinococcosis (CE) is still needed, because of the low specificity and sensitivity of the currently available commercial tools and the lack of proper evaluation of the existing recombinant antigens. In a previous work, we defined the new ELISA-B2t diagnostic tool for the detection of specific IgGs in CE patients, which showed high sensitivity and specificity, and was useful in monitoring the clinical evolution of surgically treated CE patients. Nevertheless, this recombinant antigen gave rise to false-negative results in a percentage of CE patients. Therefore, in an attempt to improve its sensitivity, we constructed B2t-derived recombinant antigens with two, four and eight tandem repeat of B2t units, and tested them by ELISA on serum samples of CE patients and patients with related parasites. The best diagnostic values were obtained with the two tandem repeat 2B2t antigen. The influence of several clinical variables on the performance of the tests was also evaluated. Finally, the diagnostic performance of the 2B2t-ELISA was compared with that of an indirect haemagglutination commercial test. The 2B2t recombinant antigen performed better than the HF and B2t antigens, and the IHA commercial kit. Therefore, this new 2B2t-ELISA is a promising candidate test for the serodiagnosis of CE in clinical settings.

Factors Influencing the Serological Response in Hepatic Echinococcus granulosus Infection

“…The performances of immunoassays are heterogeneous and influenced by the antigen and technique used and by many clinical variables. 9,10 Unfortunately, these data are often not taken into account when test performances are assessed and, in the clinical setting, when serology results are interpreted. Knowledge of serology behavior and influencing variables is crucial for clinicians to evaluate serology results in the context of each patient's condition.…”

“…Among the variables explored, stage, number, and location of cysts, presence of complications, collection of serum after treatment, and infection with other parasitic or nonparasitic diseases have been reported to influence serology results. 10 Cyst dimensions, however, have never been taken into account as a continuous variable in previous studies. In this retrospective analysis of a cohort of patients diagnosed with hepatic CE and followed in our clinic from May 2000 to June 2012, we found that not only cyst activity and time from treatment but also antigen mass influence the results of two commercial enzyme-linked immunosorbent assays (ELISA and IHA) test used in the diagnostic parasitology laboratory of our hospital.…”

A Study of Cross-Reactivity Between Recombinant EPC1 Antigen of Echinococcus granulosus in Serum from Patients with Confirmed Cystic Echinococcosis Infection and Other Parasitic Infections

“…Studies must be conducted to standardize the techniques and antigenic preparations (large quantity, high purification), characterize new antigens, produce highly purified recombinant and synthetic peptide, and detect distinct Ig classes. [24][25][26][27] Valiente-Gabioud and others 26 reported that an increase in the number of repetitive units of a specific Trypanosoma cruzi antigen could result in an enhanced antigenic response. Hernández-González and others 25 improved serodiagnosis of CE using repetitive units of antigen B.…”

“…[24][25][26][27] Valiente-Gabioud and others 26 reported that an increase in the number of repetitive units of a specific Trypanosoma cruzi antigen could result in an enhanced antigenic response. Hernández-González and others 25 improved serodiagnosis of CE using repetitive units of antigen B. Currently, using synthetic peptides instead of native or recombinant antigens has been proposed for the diagnosis of infectious diseases, and is a perfect tool for analyzing the antigenicity of biological antigens.…”

“…Currently, using synthetic peptides instead of native or recombinant antigens has been proposed for the diagnosis of infectious diseases, and is a perfect tool for analyzing the antigenicity of biological antigens. 25 Complicated structures of recombinant and native epitopes cause the cross-reactivity of epitopes with other paratopes. So far, transcriptomics approach, proteomics approach, and genomics approach have been used for designing synthetic peptides.…”