Molecular diagnosis of alveolar echinococcosis in patients based on frozen and formalin-fixed paraffin-embedded tissue samples

Parasite

Turco Celia¹  Richou Carine²  Bresson-Hadni Solange³  Courquet Sandra³  Knapp Jenny³  Millon Laurence³  Lallemand Séverine³  Demonmerot Florent³  Valmary-Degano Séverine⁴  Bourgeois Lucie⁴  Felix Sophie⁴  Monnien Franck⁴  Doussot Alexandre⁵  Heyd Bruno⁵ 

[1]Department of Digestive Surgery, Hepato-Biliary-Pancreatic and Liver Transplantation, AP-HP Pitié-Salpêtrière Hospital – Charles-Foix

[2]Department of Hepatology, University Hospital of Besançon

[3]Department of Parasitology-Mycology, National Reference Centre for Echinococcoses, University Hospital of Besançon

[4]Department of Pathology, University Hospital of Besançon

[5]Visceral, Digestive and Cancer Surgery, Hepatic Transplantation Unit, University Hospital of Besançon

关键词: echinococcus multilocularis;    molecular diagnosis;    fresh material;    ffpe;    end-point pcr;    qpcr;   

DOI  :  10.1051/parasite/2022004

来源: DOAJ

【 摘 要 】

Confirmed diagnosis of alveolar echinococcosis (AE) is based on pathological criteria and molecular evidence. This parasite-borne disease, caused by the cestode Echinococcus multilocularis, sparingly involves humans as a dead-end host. In humans, the parasite mainly colonizes the liver but can colonize any organ and cause atypical forms, often difficult to characterize clinically. Moreover, molecular methods may be suitable to make the diagnosis of AE in cases of atypical forms, extra-hepatic localizations, or immunosuppressed patients. The aim of this study was to determine the most relevant published PCR techniques, for diagnosis of AE in patients and adopt the best strategy for molecular diagnosis depending on the nature of the tested sample. In this study, we evaluated nine end-point PCR assays and one real-time PCR assay (qPCR), targeting mitochondrial genes, using a total of 89 frozen or formalin-fixed paraffin-embedded (FFPE) samples from either 48 AE or 9 cystic echinococcosis patients. Targeted fragment-genes ranged from 84 to 529 bp. Six PCR assays were able to amplify the DNA of 100% of the frozen AE-samples and for one PCR, 69.8% of the FFPE AE-samples. The 16S rrnL PCR (84 bp) was positive in PCR for 77% of the AE samples and in qPCR for 86.5%. The sensitivity of the PCR assays was higher for fresh samples and FFPE samples stored for less than 5 years. The qPCR assay further increased sensitivity for the tested samples, confirming the need for the development of an Echinococcus spp. qPCR to improve the molecular diagnosis of echinococcoses.

【 授权许可】

Unknown