Development of Two FhSAP2 Recombinant–Based Assays for Immunodiagnosis of Human Chronic Fascioliasis

Abstract

Abstract. In the United States, infection with Fasciola hepatica has been identified as an emerging disease, primarily in immigrants, refugees, and travelers. The laboratory test of choice for diagnosis of fascioliasis is detection of disease specific antibodies, most commonly uses excretory-secretory antigens for detection of IgG antibodies. Recently, recombinant proteins such as F. hepatica antigen (FhSAP2) have been used to detect IgG antibodies. The glutathione S-transferase (GST)-FhSAP2 recombinant antigen was used to develop Western blot (WB) and fluorescent bead-based (Luminex) assays to detect F. hepatica total IgG and IgG 4 antibodies. The sensitivity and specificity of GST-FhSAP2 total IgG and IgG 4 WB were similar at 94% and 98%, respectively. For the IgG Luminex assay, the sensitivity and specificity were 94% and 97%, and for the IgG 4 , the values were 100% and 99%, respectively. In conclusion, the GST-FhSAP2 antigen performs well in several assay formats and can be used for clinical diagnosis.

Case Report: Hepatic Fascioliasis in a Young Afghani Woman with Severe Wheezing, High-Grade Peripheral Eosinophilia, and Liver Lesions: A Brief Literature Review

“…The sensitivity and specificity of GST-FhSAP2 total IgG and IgG4 WB are similar at 94% and 98%, respectively. 7 The optimal treatment for fascioliasis, triclabendazole, 2,3,8-10 was requested through the FDA under an Investigational New Drug (IND) application and was then supplied by the CDC. Forty-five days after her ED presentation, the patient received treatment with two postprandial 750-mg doses (∼10 mg/kg of body weight per dose).…”

The Brief Case: What a Fluke! A Case of Fascioliasis with Pulmonary Involvement in a Peace Corps Volunteer

“…The glutathione S-transferase (GST)-FhSAP2 recombinant agent was used to develop a Western blot and fluorescent bead-based assay to detect F. hepatica IgG and IgG4 antibodies. According to studies conducted by the CDC, the sensitivity and specificity of the immunoblot assay are Ն94% and Ն98%, respectively, for patients with chronic fascioliasis (1). Cross-reactivity in the F. hepatica IgG assay has been observed among sera from schistosomiasis, toxocariasis, and hookworm specimens (22%, 50%, and 13%, respectively) (1).…”

“…strated eosinophilic microabscesses and sinusoidal eosinophilia in the liver parenchyma, but no organisms were seen on hematoxylin and eosin, Ziehl-Neelsen, and Gomori methenamine silver stains. A serum specimen was sent to the U.S. Centers for Disease Control and Prevention (CDC) for Fasciola hepatica IgG serology via immunoblotting using recombinant FhSAP2 antigen (1) and was positive. Based on this result, the characteristic radiologic features, including the serpiginous track in the liver, and significant peripheral and pulmonary eosinophilia, a diagnosis of fascioliasis was made.…”

Cell-free expression, purification and immunoreactivity assessment of recombinant Fasciola hepatica saposin-like protein-2

“…Over the last half century there has been a continuous interest in the development of cell-free expression systems based on eukaryotic organisms, which have been attributed a wide spectrum of applications that range from bioengineering [1], identification of novel drugs [2], nano-biotechnology [3], evolutionary biology [4] and high-throughput proteomics [5]. Compared to the cell-based expression systems, cell free expression systems offer great advantages, such as a shorter production process and the possibility to express multiple proteins simultaneously using PCR products without the tedious, complex and laborious cloning and transformation steps [6].…”

“…FhSAP2 has shown to be a highly specific antigen capable of detecting both, acute and chronic infection in experimental animals [10,11], as well as chronic human fascioliasis cases using ELISA or Luminex assays [4,12]. Additionally, FhSAP2 has shown to be an excellent immunogen capable of inducing partial protective immune responses in mice and rabbits challenged with F. hepatica [11,13].…”