[The COVID-19 breaker : PCR to the rescue !] / La déferlante COVID-19 : la PCR à la rescousse ! Chronique d'une gestion de crise au Laboratoire de Microbiologie clinique du CHU de Liège.

Chronicle of a crisis management at the Clinical Microbiology Laboratory of CHU Liège The SARS-CoV-2 outbreak in December 2019 in China and its expansion across the world and Europe have requested the participation of clinical laboratories as major players in the diagnosis of COVID-19, to perform PCR tests mainly on nasopharyngeal swabs. In Belgium, the first confirmed COVID-19 patient was diagnosed in early February, the first of many, especially travelers returning from winter sports. In order to meet the ever-increasing demands for testing, the Clinical Microbiology Laboratory of the CHU of Liege had to adapt to this situation: firstly, by developing manual PCR tests and then automated solutions, permitting to increase the number of analyzes by ensuring a short turnaround time of results. Then, a system for the communication of results on a large scale has been set up, and finally solutions to deal with the lack of sampling devices have been found. This first wave of the pandemic has also highlighted an unprecedented solidarity within the institution. In this article, we recount the chronology of the management of this unprecedented health crisis within the Clinical Microbiology Laboratory of the CHU of Liege.

L'émergence du virus SARS-CoV-2 en décembre 2019 en Chine et son expansion à travers le monde et l'Europe ont sollicité la participation des laboratoires de Biologie clinique en tant qu'acteurs majeurs dans le diagnostic de la COVID-19, via la réalisation de tests PCR principalement sur des prélèvements nasopharyngés. En Belgique, le premier patient confirmé COVID-19 a été diagnostiqué début février, avant d'être suivi par de nombreux cas d'infections, initialement chez des vacanciers revenant des sports d'hiver. Afin de répondre à l'augmentation du nombre de tests, le laboratoire de Microbiologie clinique du CHU de Liège a dû s'adapter en développant des tests PCR, d'abord manuels puis automatisés. Ceux-ci ont permis d'augmenter le nombre d'analyses, tout en garantissant un temps de rendu des résultats court, en mettant en place un système de communication des résultats à grande échelle et en trouvant des solutions pour faire face à la pénurie des dispositifs de prélèvement. Cette première vague de la pandémie a aussi révélé une solidarité sans précédent au sein de l'institution. Dans cet article, nous retraçons la chronologie de la gestion de cette crise sanitaire inédite au sein du laboratoire de Microbiologie clinique du CHU de Liège.

Satellite lesions accompanying herpes zoster: a new prognostic sign for high-risk zoster.

BACKGROUND: The incidence, clinical relevance and pathogenesis of single, isolated, varicella-like skin lesions occurring far beyond the primary herpes zoster (HZ)-affected dermatome remain unclear. OBJECTIVES: To search prospectively for these satellite lesions in 120 patients with HZ and to correlate their presence with a series of clinical, histological and virological data. METHODS: Relevant clinical data were recorded from 109 patients with proven HZ using immunohistochemistry on Tzanck smears. Furthermore, skin biopsies and blood samples were obtained from a subgroup of patients presenting with primary HZ with and without satellite lesions for histology, immunohistology, serology and real-time polymerase chain reaction. RESULTS: This study identified satellite lesions in 21·1% of the patients with HZ. Their presence conveyed a statistically significant relative risk (RR) for severe (RR 3·27, P < 0·001), multidermatomal (RR 10·6, P < 0·001) and multistage HZ (RR 3·30, P < 0·001); systemic signs (RR 2·08, P = 0·0031); immunosuppression (RR 2·38, P = 0·0014) and hospitalization (RR 2·94, P < 0·001). Varicella zoster virus (VZV) viraemia was higher (mean 4075 copies mL(-1) ) in patients with HZ with satellite lesions than in those without (mean 1466 copies mL(-1) ). In contrast to HZ lesions, satellite lesions often presented positive VZV immunostaining in endothelial cells, suggesting a similar pathogenesis to varicella. A limitation of this study is the centre-linked overrepresentation of immunocompromised patients. CONCLUSIONS: Total-body examination searching for satellite lesions is a rapid, simple and reliable tool for identifying patients with high-risk HZ.

Ruthenium oligonucleotides, targeting HPV16 E6 oncogene, inhibit the growth of cervical cancer cells under illumination by a mechanism involving p53.

High-risk Human Papillomaviruses (HPV) has been found to be associated with carcinomas of the cervix, penis, vulva/vagina, anus, mouth and oro-pharynx. As the main tumorigenic effects of the HPV have been attributed to the expression of E6 and E7 genes, different gene therapy approaches have been directed to block their expression such as antisense oligonucleotides (ASO), ribozymes and small interfering RNAs. In order to develop a gene-specific therapy for HPV-related cancers, we investigated a potential therapeutic strategy of gene silencing activated under illumination. Our aim according to this antisense therapy consisted in regulating the HPV16 E6 oncogene by using an E6-ASO derivatized with a polyazaaromatic ruthenium (Ru(II)) complex (E6-Ru-ASO) able, under visible illumination, to crosslink irreversibly the targeted sequence. We examined the effects of E6-Ru-ASO on the expression of E6 and on the cell growth of cervical cancer cells. We demonstrated using HPV16(+) SiHa cervical cancer cells that E6-Ru-ASO induces after illumination, a reactivation of p53, the most important target of E6, as well as the inhibition of cell proliferation with a selective repression of E6 at the protein level. These results suggest that E6-Ru ASOs, activated under illumination and specifically targeting E6, are capable of inhibiting HPV16(+) cervical cancer cell proliferation.

[Varicelle zoster virus, an alphaherpesvirus different from others]. / Le virus de la varicelle et du zona : un alphaherpesvirus pas vraiment comme les autres...

Varicella Zoster virus (VZV) is an alphaherpesvirus responsible for two well-known pathologies. It is indeed the etiological agent of varicella (chickenpox), a childhood infection and zoster (shingles) which results from the reactivation of the virus remained latent in sensory ganglia. Only eight of the 120 Herpesviruses described so far, among which VZV and Herpes Simplex type-1 and type 2 (HSV-1, -2), are able to infect humans. For many years, HSV-1, which has been extensively studied has been considered as the prototype of this family. Nevertheless, data accumulated over the last 15 years tend to demonstrate that VZV is quite different from its cousin, particularly concerning the mechanisms that control latency. Epidemiological data confirm the differences between these two viruses : in our temperate countries, VZV infects very young children and zoster, usually observed only once is more frequent in the elderly. On the contrary, primary infections due to HSV-1 happen later and reactivations episodes are numerous and decrease with age. A better understanding of the VZV biology has allowed to develop efficacious antiviral compounds and to produce a vaccine whose efficacy has been demonstrated in the United States where a universal varicella vaccination program has started 10 years ago.

Varicella-Zoster virus gene expression in latently infected rat dorsal root ganglia.

Latent infection of human ganglia with Varicella-Zoster virus (VZV) is characterized by a highly restricted pattern of viral gene expression. To enhance understanding of this process we used in situ hybridization (ISH) in a rat model of VZV latency to examine expression of RNA corresponding to eight different VZV genes in rat dorsal root ganglia (DRG) at various times after footpad inoculation with wild-type VZV. PCR in situ amplification was also used to determine the cell specificity of latent VZV DNA. It was found that the pattern of viral gene expression at 1 week after infection was different from that observed at the later times of 1 and 18 months after infection. Whereas multiple genes were expressed at 1 week after infection, gene expression was restricted at the later time points when latency had been established. At the later time points after infection the RNA transcripts expressed most frequently were those for VZV genes 21, 62, and 63. Gene 63 was expressed more than any other gene studied. While VZV DNA was detected almost exclusively in 5-10% of neurons, VZV RNA was detected in both neurons and nonneuronal cells at an approximate ratio of 3:1. A newly described monoclonal antibody to VZV gene 63-encoded protein was used to detect this protein in neuronal nuclei and cytoplasm in almost half of the DRG studied. These results demonstrate that (1) this rat model of latency has close similarities in terms of viral gene expression to human VZV latency which makes it a useful tool for studying this process and its experimental modulation and (2) expression of VZV gene 63 appears to be the single most consistent feature of VZV latency.