Evaluation of the diagnostic value of the immunoblotting and ELISA tests using recombinant Em18 antigen in human alveolar echinococcosis from Xingjiang China

Abstract

Alveolar echinococcosis (AE) is a prevalent epidemic in the northern hemisphere, especially in central Europe and western China. Serum diagnosis is important for patients with AE, especially during the first screening. The present study purified the recombinant Em18-GST (rEm18-GST), and detected its diagnostic performance in human alveolar echinococcosis patients of Xinjiang, China with immunoblotting (IB) and enzyme-linked immunosorbent assay (ELISA). Serum samples were collected from 50 patients with AE, 222 patients with cystic echinococcosis (CE), 158 patients with other unrelated infections and 106 healthy individuals. The IB results showed that serum samples of 47 patients with AE and 12 patients with CE were rEm18-positive. However, only one sample from patients with cancer showed a cross-reaction with rEm18 in IB. The overall sensitivity was 94%, and the total specificity was 96.58%. For the rEm18 results using ELISA, the sera of 46 patients with AE were positive, and the overall sensitivity was 92%. In conclusion, compared with imaging tools, including computed tomography, magnetic resonance imaging and positron emission tomography, rEm18 has considerable advantages for AE serodiagnosis.

Evaluation of Serological Markers in Alveolar Echinococcosis Emphasizing the Correlation of PET-CTI Tracer Uptake with RecEm18 and Echinococcus-Specific IgG

“…Due to the small number of patients initially evaluated for the recEm18 ELISA, Bordier provides neither data on sensitivity nor specificity in the manufacturer's instructions. However, the performance of both commercially available and in-house recEm18 platforms has been investigated by several groups and shows sensitivities ranging from 80 to 92% [14,15]. Unsurprisingly, we found similar frequencies of positive results in a group of N = 59 patients with confirmed AE, with 93.2% for the Virion/Serion Echinococcus IgG ELISA and likewise 79.7% for both the Bordier Em2+ and recEm18 ELISA.…”

Investigating new serological and tissue markers for the follow‐up of patients operated for alveolar echinococcosis

“…Serology assays showed a significant decrease in anti‐Em18 and PD‐L1 levels after surgery. The value of anti‐Em18 for the follow‐up of AE patients was largely demonstrated and is well recognized 5,6,8 . The programmed death‐1 (PD‐1)/PD‐ligand 1 (PD‐L1) signalling pathway is a negative regulatory mechanism that inhibits T‐cell proliferation and cytokine production.…”

“…The value of anti-Em18 for the follow-up of AE patients was largely demonstrated and is well recognized. 5,6,8 The programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) signalling pathway is a negative regulatory mechanism that inhibits T-cell proliferation and cytokine production. Soluble PD-1 and PD-L1 levels in cystic echinococcosis were shown to decrease significantly after radical surgery and albendazole treatment.…”

“…Current options that are currently available for follow‐up are mainly recEm18‐ELISA that has shown predictive values 5,6 . Indeed, upon complete surgical removal of the parasite, the decrease in Em18 antibody levels in serum was shown to be early and significant 6,8 . Thus, recEm18‐ELISA in combination with imaging, proved to be optimal to monitor AE patients 6 .…”

“…5,6 Indeed, upon complete surgical removal of the parasite, the decrease in Em18 antibody levels in serum was shown to be early and significant. 6,8 Thus, recEm18-ELISA in combination with imaging, proved to be optimal to monitor AE patients. 6 In the context of AE management after surgery, the availability of biomarkers predictive of parasitic activity could be helpful for the patient's follow-up.…”