Evaluation of total immunoglobulin G and subclass antibodies in an enzyme-linked immunosorbent assay for serodiagnosis of human amebic liver abscess

Abstract

Background Amebic liver abscess (ALA) caused by Entamoeba histolytica is usually diagnosed based on its clinical symptoms, medical imaging abnormalities of the liver, and serological tests, the most common being the enzyme-linked immunosorbent assay (ELISA). For more than three decades, no investigation has evaluated the diagnostic performance of immunoglobulin G (IgG) subclasses in the serodiagnosis of ALA. Herein, we assessed the efficiencies of anti-amebic IgG and IgG subclasses for diagnosing ALA. Methods A serological ELISA-based test was performed to assess its diagnostic performance using a total of 330 serum samples from ALA patients (n = 14), healthy individuals (n = 40), and patients with other diseases (n = 276). Results ELISA targeting the total IgG antibody to E. histolytica antigen exhibited 100% sensitivity 95% CI [76.8–100.0] and 97.8% specificity 95% CI [95.5–99.1], whereas the assay targeting IgG1 showed the same sensitivity (100% 95% CI [76.8–100.0]) and a slightly higher specificity (99.1% 95% CI [97.3–99.8]). The other IgG subclasses (IgG2, IgG3, and IgG4) displayed a lower sensitivity and specificity. The sensitivity and specificity did not significantly differ between tests measuring total IgG and IgG1 (Exact McNemar’s test; p > 0.05), with a concordance of 98.2%, represented by a Cohen’s kappa of 0.83 (p < 0.001), indicating almost perfect agreement. Conclusion ELISA targeting IgG1 can provide valuable information to clinicians in differentiating ALA from other parasitic diseases, cancers, cirrhosis, and viral hepatitis. However, enzyme-conjugated anti-human total IgG is cheaper than anti-human IgG subclasses. Therefore, we suggest that total IgG-based ELISA is sufficient for the routine serodiagnosis of human ALA and possibly other clinical manifestations of invasive amebiasis.

Development and evaluation of an immunochromatography-based point-of-care test kit for a rapid diagnosis of human cysticercosis

“…Cysticercosis was diagnosed in various ways ( Carpio et al, 2016 ; Garcia et al, 2014 ) including clinical signs, CT scan, MRI and ultrasonography, serological and histopathological examinations and/or molecular analysis ( Table 1 ; Supplementary Table 1). Serum samples from cases other than cysticercosis were as follows: healthy persons who were free from any intestinal parasitic infections by stool examination and/or serologically negative against any helminth infections (10 Thai and 20 Japanese individuals); sparganosis ( n = 22, including 1 cerebral sparganosis); cystic echinococcosis ( n = 30) and alveolar echinococcosis cases ( n = 6) which were diagnosed by ultrasonography and serology ( Yu et al, 2008 ); taeniasis saginata ( n = 5); angiostrongyliasis with eosinophilic meningoencephalitis ( n = 16); gnathostomiasis (n = 5); toxocariasis ( n = 10) ( Yamasaki et al, 2000 ); trichinosis (n = 5); fascioliasis gigantica ( n = 12); paragonimiasis ( n = 15, including an ectopic cerebral paragonimiasis case due to Paragonimus westermani ); amoebiasis (four cases with amoebic liver abscess and one cerebral amoebiasis case) ( Janwan et al, 2022 ); toxoplasmosis (n = 1). The use of human serum was approved by the Ethics Committee for Human Research, Khon Kaen University (HE 621265) and the Medical Ethics Committee of the National Institute of Infectious Diseases, Tokyo, Japan (Nos.…”

Amebic liver abscess: An update

“…Anti-amebic antibodies can be detected in about 95% of cases of ALA. Recently, ELISA, targeting the IgG1 subclass antibody to EH exhibited 100% sensitivity and 99.1% specificity in patients with ALA[ 62 ]. However, anti-amebic antibodies become detectable in serum only 5-7 d after infection and continue to exist for 6-12 months after the infection has been eradicated.…”