Zait H, Hamrioui B. Human cystic echinococcosis: Serological diagnosis by indirect hemagglutination test, enzyme-linked immunosorbent assay, immunoelectrophoresis, and immunoblotting in surgically confirmed patients versus cases diagnosed by imaging techniques.
Med Mal Infect 2019;
50:676-683. [PMID:
31727467 DOI:
10.1016/j.medmal.2019.10.001]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 11/01/2018] [Accepted: 10/01/2019] [Indexed: 10/25/2022]
Abstract
INTRODUCTION
Human cystic echinococcosis (CE) diagnosis is based on imaging findings and serology. Serology is the first-line test followed by imaging tests.
MATERIALS AND METHODS
A total of 268 serum samples from CE patients were included in this study. The serodiagnosis was made simultaneously by indirect hemagglutination assay (IHA), enzyme-linked immunosorbent assay (ELISA), immunoblotting test (IB), and immunoelectrophoresis (IEP).
RESULTS
In serum samples belonging to surgically confirmed CE patients, we observed a percentage of positivity of 83.7% [77.2%-89.0%] and 80.7% [73.9%-86.4%] for IHA and IgG-ELISA, respectively. IgG-IB was associated with a higher positivity rate than IEP with 81.3% [74.6%-86.9%] and 62.0% [54.2%-69.5%], respectively. IHA and ELISA results were analyzed using cut-off generated by receiver operating curves. The best diagnostic performances were achieved by IHA (cut-off ≥1/128) and ELISA (>1.16 index). Sensitivities reported in patients with suggestive imaging findings and positive Echinococcus IB were 86.2% [78.0%-92.2%], 72.5% [62.8%-80.9%], 49.0% [39.0%-59.1%] for IHA, IgG-ELISA, and IEP, respectively. All tests gave false negative results in the confirmed CE group. Overall, 18.6% of negative results were obtained by IgG-IB test. Cross-reactivities with non-hydatid serum samples were observed in all tests. Only one patient carrying Taenia saginata serum cross-reacted with 8/12 kDa band by IB. We observed specificity at 73% [63.2%-81.4%], 87% [78.8%-92.9%], 99% [94.6%-100.0%], and 99% [94.6%-100.0%] with IHA, IgG-ELISA, IEP, and IgG-IB, respectively. Serology was less sensitive (74%) in lung cysts. Sensitivity was better in liver cysts, especially by IgG-IB (96%).
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