Single-photon emission computed tomography facilitates the diagnosis of vascular encephalitis in cases of severe Long Covid and correlates with transcriptomic studies

peer reviewedSince July 2021, a cohort exceeding 100 Long Covid patients has been identified during family medicine consultations in Charleroi, Belgium. The diagnosis of Long Covid, characterized by a constellation of medically unexplained symptoms, is predominantly reliant on clinical assessment. Conventional biological examinations and imaging studies yield no fruitful findings. In instances of severe presentation, cognitive dysfunction has prompted the utilization of single-photon emission computed tomography (SPECT CT), a modality capable of detecting anomalies in cerebral blood perfusion. Furthermore, through collaboration with the Covid Human Genetic Effort network, comprehensive multi-omics investigations involving 80 patients have been conducted During clinical encounters and through the comprehensive review of medical histories, a constellation of medically unexplained symptoms has become evident. These symptoms encompass cognitive impairments, profound fatigue, exertional exhaustion, and procedural memory disturbances, among numerous others, occurring in individuals who were previously in good health or exhibited stable health conditions. To assess the severity of cases as perceived by healthcare providers, the Wonca Duke Overall Severity Index (DUSOI) has been employed, graded on a scale ranging from 0 to 5. Simultaneously, to gauge the functional status from the patients' perspective, the COOP Wonca Charts have been utilized, featuring scores ranging from 6 (representing a state of health) to 30 (indicating severe functional impairment). In instances where cases are deemed very severe (DUSOI exceeding 3) and where there is a pronounced alteration in global health status (exceeding 20), it has been opted to request single-photon emission computed tomography (SPECT-CT) scans for further evaluation. Notably, the majority of patients have consented to participate in multiomics research by providing blood samples. A total of 53 patients with severe long-standing long covid agreed to undergo SPECT-CT. Cerebral flow disorders were detected in 48 of them. This kind of protocol is usual in such cases ;The tracer fixation exhibits marked heterogeneity, with more pronounced hypo-fixations observed in the right parieto-occipital, left parietal, right fronto-parietal, and bilateral posterior parietal regions. There exists a robust correlation between SARS-CoV-2 viral RNA levels and the outcomes observed in SPECT-CT scans. The discussion will be conducted as part of the presentation. With our thanks to the people who supported this research: Fundation Roi Bauduin, Prof. Casanova (Rockefeller), Prof Isabelle Meyts (Rega Institute)Depuis juillet 2021, une cohorte de plus de 100 patients atteints de Long Covid a été identifiée lors de consultations de médecine familiale à Charleroi, en Belgique. Le diagnostic de Long Covid, caractérisé par une constellation de symptômes médicalement inexpliqués, repose principalement sur l'évaluation clinique. Les examens biologiques conventionnels et les études d'imagerie ne donnent pas de résultats fructueux. Dans les cas les plus graves, le dysfonctionnement cognitif a conduit à l'utilisation de la tomographie par émission monophotonique (SPECT CT), une modalité capable de détecter les anomalies de la perfusion sanguine cérébrale. En outre, grâce à la collaboration avec le réseau Covid Human Genetic Effort, des études multi-omiques ont été menées sur 80 patients Au cours des rencontres cliniques et grâce à l'examen complet des antécédents médicaux, une constellation de symptômes médicalement inexpliqués est devenue évidente. Ces symptômes comprennent des troubles cognitifs, une fatigue profonde, un épuisement à l'effort et des troubles de la mémoire procédurale, entre autres, chez des personnes qui étaient auparavant en bonne santé ou dont l'état de santé était stable. Pour évaluer la gravité des cas telle qu'elle est perçue par les prestataires de soins de santé, l'indice Wonca Duke Overall Severity Index (DUSOI) a été utilisé, sur une échelle allant de 0 à 5. Simultanément, pour évaluer l'état fonctionnel du point de vue des patients, le COOP Wonca Charts a été utilisé, avec des scores allant de 6 (représentant un état de santé) à 30 (indiquant une déficience fonctionnelle sévère). Lorsque les cas sont jugés très graves (DUSOI supérieur à 3) et qu'il y a une altération prononcée de l'état de santé global (supérieur à 20), il a été décidé de demander une tomographie par émission monophotonique (SPECT-CT) pour une évaluation plus approfondie. Notamment, la majorité des patients ont consenti à participer à la recherche multiomique en fournissant des échantillons de sang. Au total, 53 patients atteints de Covid sévère de longue date ont accepté de subir une SPECT-CT. Des troubles du flux cérébral ont été détectés chez 48 d'entre eux. Ce type de protocole est habituel dans de tels cas ; La fixation du traceur présente une hétérogénéité marquée, avec des hypofixations plus prononcées observées dans les régions pariéto-occipitale droite, pariétale gauche, fronto-pariétale droite et pariétale postérieure bilatérale. Il existe une corrélation robuste entre les niveaux d'ARN viral du SRAS-CoV-2 et les résultats observés dans les scanners SPECT-CT. Avec nos remerciements aux personnes qui ont soutenu cette recherche : Fondation Roi Baudouin, Prof. Casanova (Rockefeller), Prof Isabelle Meyts (Institut Rega)

Unraveling the Enigma of Long Covid: A Journey from Clinical Uncertainty to Multi-Omics Research.

peer reviewedIn family medicine, it's confronting the uncertainties posed by a new syndrome that has driven translational research forward, as this poster illustrates. Readers are invited to follow the arrows that trace the evolution of our research initiated in July 2021. Several months after the acute phase of a Covid-19 infection, previously healthy or stable individuals present with a range of medically unexplained symptoms. These include cognitive impairment, profound fatigue, exertional exhaustion, procedural memory impairment and anomia. Despite rigorous efforts, traditional biological examinations and imaging studies fail to yield conclusive results. In response to this puzzling clinical scenario, a classified bibliography freely accessible on Zotero was developed. An exhaustive analysis of the literature ultimately led to the diagnosis of Long Covid, which is the most plausible explanation for these enigmatic symptoms. Guedj's exploration of 18 FDG PET scan hypometabolism in patients with Long Covid then stimulated the use of single-photon emission computed tomography (SPECT CT). This imaging modality, available in primary care in Belgium, has shown to be effective in detecting abnormalities in cerebral blood perfusion. In addition, collaborative efforts with the Covid Human Genetic Effort network have led to in-depth multi-omics investigations of over 80 patients in our cohort (104 patients to date). At the clinical level, patients are given the opportunity to express their concerns and undergo symptom severity assessments. Their clinical profiles, pre-covid problems identified by International Classification of Primary Care codes, vaccination history, medical history and disease course are documented. Testimonies are collected through interviews and written reports, enabling us to support, understand and defend their rights. With the informed consent of patients and the approval of the University of Liège Ethics Committee, blood samples have been taken and a database created. This serves as a resource for research at various levels, including qualitative studies conducted by students from various Belgian universities, as well as transcriptomic, proteomic and genomic analyses carried out in collaboration with institutions such as the Rega Institute (KUL), the Brodin laboratory (Stockholm), Pharmacogenomics (UGent), and Necker (Paris). The neurobiology laboratory at the University of Namur is interested in exploring neuronal antibodies. Finally, the textual data collected can be used to develop an automated terminology and ontology tool, in collaboration with Macquarie (Australia) and the University of Rouen (France), capable of extracting relevant textual features from electronic medical records. Bibliography is central to the whole process.En médecine familiale, c'est la confrontation aux incertitudes posées par un nouveau syndrome qui a fait avancer la recherche translationnelle, comme l'illustre ce poster. Le lecteur est invité à suivre les flèches qui retracent l'évolution de notre recherche initiée en juillet 2021. Plusieurs mois après la phase aiguë d'une infection à Covid-19, des personnes auparavant en bonne santé ou stables présentent une série de symptômes médicalement inexpliqués. Il s'agit notamment de troubles cognitifs, de fatigue profonde, d'épuisement à l'effort, de troubles de la mémoire procédurale et d'anomie. Malgré des efforts rigoureux, les examens biologiques traditionnels et les études d'imagerie ne donnent pas de résultats concluants. En réponse à ce scénario clinique déroutant, une bibliographie classée accessible librement sur Zotero a été élaborée. Une analyse exhaustive de la littérature a finalement abouti au diagnostic de Long Covid chez ces patients, qui est l'explication la plus plausible de ces symptômes énigmatiques. L'exploration par Guedj de l'hypométabolisme du 18 FDG PET scan chez les patients atteints de Covid long a ensuite stimulé l'utilisation de la tomographie par émission monophotonique (SPECT CT). Cette modalité d'imagerie, disponible en soins primaires en Belgique, s'est révélée efficace pour détecter les anomalies de la perfusion sanguine cérébrale. En outre, des efforts de collaboration avec le réseau Covid Human Genetic Effort ont conduit à des investigations multi-omiques approfondies sur plus de 80 patients de notre cohorte (106 patients à ce jour dans la cohorte). Au niveau clinique, les patients ont la possibilité d'exprimer leurs préoccupations et de subir des évaluations de la gravité des symptômes. Leurs profils cliniques, leurs problèmes pré-covid identifiés par les codes de la Classification internationale des soins primaires, leurs antécédents de vaccination, leurs antécédents médicaux et l'évolution de la maladie sont documentés. Des témoignages sont recueillis par le biais d'entretiens et de rapports écrits, ce qui nous permet de soutenir, de comprendre et de défendre leurs droits. Avec le consentement éclairé des patients et l'approbation du Comité d'éthique de l'Université de Liège et de Leuven, des échantillons de sang ont été prélevés et une base de données a été créée. Celle-ci sert de ressource pour la recherche à différents niveaux, y compris des études qualitatives menées par des étudiants de différentes universités belges, ainsi que des analyses transcriptomiques, protéomiques et génomiques réalisées en collaboration avec des institutions telles que l'Institut Rega (KUL), le laboratoire Brodin (Stockholm), Pharmacogenomics (UGent), et Necker (Paris). Le laboratoire de neurobiologie de l'Université de Namur est intéressé par l'exploration des anticorps neuronaux. Enfin, les données textuelles collectées peuvent être utilisées pour développer un outil automatisé de terminologie et d'ontologie, en collaboration avec Macquarie (Australie) et l'Université de Rouen (France), capable d'extraire des caractéristiques textuelles pertinentes à partir de dossiers médicaux électroniques. La bibliographie est au cœur du processus

Follow-up of a cohort of Long Covid patients in family medicine. 2021-2023

peer reviewedÉtude d’une cohorte de 64 patients (au 1/12/2022), âge moyen 44,2 ans (12-79), avec plaintes multiformes et symptômes médicalement inexpliqués plusieurs mois après un COVID. Les patients sont identifiés d’abord au sein de la consultation usuelle puis à l’extérieur, par effet boule de neige. Cette étude de cohorte, sans groupe contrôle, dont les résultats sont mis à jour régulièrement, veut contribuer à la compréhension d’un nouveau syndrome appelé Long Covid, de soutenir les patients et de leur montrer, dans un esprit de partenariat, que même dans l’incertitude, ils ne sont pas abandonnés

Zinc/copper imbalance reflects immune dysfunction in human leishmaniasis: an ex vivo and in vitro study

BACKGROUND: The process of elimination of intracellular pathogens, such as Leishmania, requires a Th1 type immune response, whereas a dominant Th2 response leads to exacerbated disease. Experimental human zinc deficiency decreases Th1 but not Th2 immune response. We investigated if zinc and copper levels differ in different clinical forms of leishmaniasis, and if these trace metals might be involved in the immune response towards the parasite. METHODS: Blood was collected from 31 patients with either localized cutaneous (LCL), mucosal (ML) or visceral (VL) leishmaniasis, as well as from 25 controls from endemic and non-endemic areas. Anti-Leishmania humoral and cellular immune response were evaluated by quantifying specific plasma IgG, lymphoproliferation and cytokine production, respectively. Plasma levels of Cu and Zn were quantified by atomic absorption spectrophotometry. RESULTS: A significant decrease in plasma Zn was observed in all three patient groups (p < 0.01 for LCL and ML, p < 0.001 for VL), as compared to controls, but only VL (7/10) and ML (1/7) patients displayed overt Zn deficiency. Plasma Cu was increased in LCL and VL (p < 0.001) but not in ML, and was strongly correlated to anti-Leishmania IgG (Spearman r = 0.65, p = 0.0028). Cu/Zn ratios were highest in patients with deficient cellular (VL<<LCL<ML) and exacerbated humoral (VL>LCL>ML) immune response. Ex vivo production of parasite-induced IFN-γ was negatively correlated to plasma Cu levels in LCL (r = -0.57, p = 0.01). In vitro, increased Cu levels inhibited IFN-γ production. CONCLUSIONS: 1. Zn deficiency in VL and ML indicate possible therapeutic administration of Zn in these severe forms of leishmaniasis. 2. Plasma Cu positively correlates to humoral immune response across patient groups. 3. Environmentally or genetically determined increases in Cu levels might augment susceptibility to infection with intracellular pathogens, by causing a decrease in IFN-γ production

Systems Approach Reveals Nuclear Factor Erythroid 2-Related Factor 2/Protein Kinase R Crosstalk in Human Cutaneous Leishmaniasis

Leishmania parasites infect macrophages, causing a wide spectrum of human diseases, from cutaneous to visceral forms. In search of novel therapeutic targets, we performed comprehensive in vitro and ex vivo mapping of the signaling pathways upstream and downstream of antioxidant transcription factor [nuclear factor erythroid 2-related factor 2 (Nrf2)] in cutaneous leishmaniasis (CL), by combining functional assays in human and murine macrophages with a systems biology analysis of in situ (skin biopsies) CL patient samples. First, we show the PKR pathway controls the expression and activation of Nrf2 in Leishmania amazonensis infection in vitro. Nrf2 activation also required PI3K/Akt signaling and autophagy mechanisms. Nrf2- or PKR/Akt-deficient macrophages exhibited increased levels of ROS/RNS and reduced expression of Sod1 Nrf2-dependent gene and reduced parasite load. L. amazonensis counteracted the Nrf2 inhibitor Keap1 through the upregulation of p62 via PKR. This Nrf2/Keap1 observation was confirmed in situ in skin biopsies from Leishmania-infected patients. Next, we explored the ex vivo transcriptome in CL patients, as compared to healthy controls. We found the antioxidant response element/Nrf2 signaling pathway was significantly upregulated in CL, including downstream target p62. In silico enrichment analysis confirmed upstream signaling by interferon and PI3K/Akt, and validated our in vitro findings. Our integrated in vitro, ex vivo, and in silico approach establish Nrf2 as a central player in human cutaneous leishmaniasis and reveal Nrf2/PKR crosstalk and PI3K/Akt pathways as potential therapeutic targets

Leishmania braziliensis Subverts Necroptosis by Modulating RIPK3 Expression

Leishmania braziliensis infection causes skin ulcers, typically found in localized cutaneous leishmaniasis (LCL). This tissue pathology associates with different modalities of cell necrosis, which are subverted by the parasite as a survival strategy. Herein we examined the participation of necroptosis, a specific form of programmed necrosis, in LCL lesions and found reduced RIPK3 and PGAM5 gene expression compared to normal skin. Assays using infected macrophages demonstrated that the parasite deactivates both RIPK3 and MLKL expression and that these molecules are important to control the intracellular L. braziliensis replication. Thus, LCL-related necroptosis may be targeted to control infection and disease immunopathology

STAT2 signaling restricts viral dissemination but drives severe pneumonia in SARS-CoV-2 infected hamsters

Emergence of SARS-CoV-2 causing COVID-19 has resulted in hundreds of thousands of deaths. In search for key targets of effective therapeutics, robust animal models mimicking COVID-19 in humans are urgently needed. Here, we show that Syrian hamsters, in contrast to mice, are highly permissive to SARS-CoV-2 and develop bronchopneumonia and strong inflammatory responses in the lungs with neutrophil infiltration and edema, further confirmed as consolidations visualized by micro-CT alike in clinical practice. Moreover, we identify an exuberant innate immune response as key player in pathogenesis, in which STAT2 signaling plays a dual role, driving severe lung injury on the one hand, yet restricting systemic virus dissemination on the other. Our results reveal the importance of STAT2-dependent interferon responses in the pathogenesis and virus control during SARS-CoV-2 infection and may help rationalizing new strategies for the treatment of COVID-19 patients. SARS-CoV-2 infection can result in severe lung inflammation and pathology, but host response remains incompletely understood. Here the authors show in Syrian hamsters that STAT2 signaling restricts systemic virus dissemination but also drives severe lung injury, playing a dual role in SARS-CoV-2 infection