Use of LoopDeelab during the COVID-19 Pandemic: An Innovative Device for Field Diagnosis.

Rapid and accurate diagnosis of SARS-CoV-2 infection is essential for the management of the COVID-19 outbreak. RT-LAMP LoopDeetect COVID-19 (LoopDeescience, France) is a rapid molecular diagnostic tool which operates with the LoopDeelab (LoopDeescience, France) device. RAPID COVID is a prospective double-blind research protocol which was conducted to evaluate the concordance between Loopdeetect COVID-19 and RT-PCR Allplex 2019 n-Cov (Seegene, Korea). Between 11 May 2020 and 14 June 2021, a total of 1122 nasopharyngeal swab specimens were collected, of which 741 were finally analysed. There were 32 "positive" and "indeterminate" RT-PCR results. The intrinsic performances of Loopdeetect COVID-19 are equivalent to other commercial RT-LAMP PCR COVID-19 kits, with a sensitivity and specificity of 69.23% [CI 95%: 48.21-85.67] and 100% [CI 95%: 99.58-100.00], respectively. To the best of our knowledge, LoopDeelab is the only LAMP PCR diagnostic device allowing such a fast and reliable analysis with low-cost equipment; this makes it a new and innovative technology, designed for field use. This device being portable, the development of other detection kits will be useful for the management of epidemics with a high attack rate and would facilitate the rapid application of health measures.

Identification of a novel splice site mutation in the SERAC1 gene responsible for the MEGDHEL syndrome.

BACKGROUND: MEGDHEL is an autosomal recessive syndrome defined as 3-MEthylGlutaconic aciduria (3-MGA) with Deafness, Hepatopathy, Encephalopathy, and Leigh-like syndrome on magnetic resonance imaging, due to mutations in the SERAC1 (Serine Active Site Containing 1) gene, which plays a role in the mitochondrial cardiolipin metabolism. METHODS: We report the case of a young patient who presented with a convulsive encephalopathy, 3-methylglutaconic aciduria, deafness, and bilateral T2 hypersignals of the putamen and the thalami, who passed away at 8 years of age. RESULTS: Analysis of nuclear genes using an ampliSeq™ targeted custom panel disclosed two compound heterozygous variants in the SERAC1 gene: a nonsense substitution in exon 4, c.202C>T, resulting in a premature stop codon (p.Arg68*), and a novel variant at a canonical splicing site upstream exon 4 (c.129-1G>C). mRNAs sequencing from the fibroblasts of the patient showed that the splice site variant resulted in exon 3 skipping without frameshift while Western blot experiments showed the absence of SERAC1 expression compared to controls and abnormal filipin staining. CONCLUSION: We showed that the loss of the putative transmembrane domain of SERAC1, due to a novel splice site variant, impairs the protein expression and is responsible for the MEGDHEL syndrome.

Enterovirus in arteriosclerosis: a pilot study.

BACKGROUND: Various pathogens have been suspected to play a role in the initiation or amplification of the atherosclerotic lesions. Both experimental and epidemiological arguments plead for a possible role of enterovirus in this process. OBJECTIVE: To determine the prevalence of enterovirus genome in atherosclerotic plaques, in comparison with Chlamydia pneumoniae, human cytomegalovirus (hCMV) and herpes simplex virus. STUDY DESIGN: Pilot study on 18 patients who underwent artery resection. Five artery samples were tested for each patient and each pathogen by using PCR techniques whose sensitivity was evaluated for this kind of specimen. The quality of the extraction step was assessed by amplification of a fragment of the human aldolase A gene. RESULTS: The genome of at least one infectious agent was detected in artery samples from 7 of the 18 patients (38.9%). In all cases, only one of the five aliquots was found positive; a confirmation was done by sequencing the PCR product. With regards to enterovirus, four patients (22.2%) were detected positive (one of them being also positive for hCMV). CONCLUSIONS: These results suggest that small amounts of enterovirus genome are commonly found in lesions of patients with advanced arteriosclerosis. Further studies are needed to evaluate the clinical significance of this association.

Detection of hepatitis C virus antibodies and RNA among medicolegal autopsy cases in Northern France.

Forensic medical personnel are at risk of exposure to blood-borne viruses including hepatitis C virus (HCV). The aim of this study was to determine prevalence of HCV markers among a cadaver population at the medicolegal institute in Lille. Seventy-seven consecutive cadavers were screened for antibodies to HCV and for HCV RNA. Positive results were confirmed by an immunoblot assay. Fifty-three cadavers had a histopathologic study. Anti-HCV was detected in 13 (16.9%) and accompanied by HCV RNA in 7 (9%) cases. The rate of HCV RNA detection among seropositive cases was 53.8%. Five cases had histopathologic lesions suggestive of hepatitis. This is the first HCV RNA screening in forensic cadavers. The results highlight the high prevalence rate of HCV cases in medicolegal practice in Lille. All forensic specimens should be treated as potentially infectious and universal precautions should be taken.

Correlation between the anti-virus-induced cytopathic effect activity of interferon-alpha subtypes and induction of MxA protein in vitro.

There are several interferon-alpha (IFN-alpha) subtypes. Mechanism of disparity in biological effects among members of IFN-alpha subtypes remains unexplained. Biological activity of IFN-alpha is mediated in part by induction of intracellular antiviral proteins. We studied whether differences in biologic effects of IFN-alpha subtypes may rely on their antiviral protein inducing effect. Intracellular induction of MxA protein and anti-virus-induced cytopathic effect (CPE) activity of 11 IFN-alpha subtypes in human amnion WISH cells have been studied. MxA protein quantitation in cell lysates was performed by immunochemiluminescence assay and anti-virus-induced CPE activity was assessed by protection against vesicular stomatitis virus (VSV)-induced CPE. Range of MxA values was high when cells were treated with 10 and 100 IU/ml of each IFN-alpha subtype. Levels of MxA correlated with anti-VSV-induced CPE obtained with 10 IU/ml IFN-alpha subtype. Together our data show a disparity in MxA-inducing activity of IFN-alpha subtypes and suggest that differences in anti-VSV-induced CPE of IFN-alpha subtypes in WISH cells can be related to their different ability to induce MxA.