Link to Pubmed [PMID] – 32759355
Link to DOI – JCM.01153-2010.1128/JCM.01153-20
J. Clin. Microbiol. 2020 Aug; ():
Amoebic liver abscess (ALA) is regularly seen in travelers or immigrants from tropical countries. The diagnosis relies on liver imaging that is not specific, and the detection of anti-Entamoeba histolytica antibodies, which cannot distinguish acute from former infection. We tested whether E. histolytica DNA detection in serum can improve the diagnosis of ALA. We retrospectively tested available serum samples from patients with ALA and non-ALA liver space-occupying lesions between 01/01/2010 and 11/30/2019. The quantitative PCR (qPCR) assay tested specifically amplifies a 99-bp fragment of the small-subunit rRNA gene of E. histolytica We analyzed 76 samples (ALA=19; non-ALA=57) from 76 patients collected within 6 days before and after the anti-amoebic treatment. Serum qPCR was positive in 17 of 19 ALA patients and in none of the control patients (sensitivity and specificity were 89.5% and 100%, respectively). In parallel, the sensitivity and specificity of the anti-E. histolytica antibody detection were 100% and 89.5%, respectively. The two false-negative qPCR results may be explained by ongoing metronidazole treatment or a possible persistent seropositivity that is not caused by the current liver abscess. Additionally, out of 12 abscess pus aspirates (ALA=5; non-ALA=7) tested, 5 were qPCR positive and 7 were qPCR negative with concordant results on serum.This study demonstrates that cell-free circulating E. histolytica DNA can be detected in serum in ALA. This may assist in both positive diagnoses and treatment efficacy follow-up. The origin of this circulating DNA remains to be investigated.