Characteristics of SARS-CoV-2, COVID-19, and laboratory diagnosis / Características del SARS-CoV-2, COVID-19 y su diagnóstico en el laboratorio

La enfermedad COVID­19 es causada por el virus SARS-CoV-2, descrito por primera vez en diciembre del 2019 en Wuhan, China, y declarada en marzo del 2020 como una pandemia mundial. Actualmente existen diversos métodos diagnósticos para COVID-19, siendo el estándar de oro la detección del material genético mediante la reacción en cadena de la polimerasa (PCR), en su variante, la RT-PCR, que detecta el material genético de tipo ARN presente en el virus. Sin embargo, es necesario disponer de pruebas rápidas con alta sensibilidad y precisión para realizarlas a gran escala y brindar un diagnóstico oportuno. Adicionalmente, se debe disponer de otras herramientas que, si bien no van a establecer un diagnóstico, le van a permitir al profesional brindar un mejor manejo clínico y epidemiológico que ayuden a predecir el agravamiento del paciente y su posible ingreso a UCI, destacando entre estas los niveles de dímero D, linfocitos, ferritina, urea y creatinina, entre otras. En esta revisión se evalúa la utilidad y limitaciones de los diferentes métodos diagnósticos para COVID-19, al igual que las características, fisiopatología y respuesta inmune al SARS-CoV-2, así como algunos aspectos preanalíticos de importancia que ayudan a minimizar errores en el diagnóstico como consecuencia de procedimientos incorrectos en la toma, transporte y conservación de la muestra, y que permiten al profesional emitir resultados veraces y confiables. Lo anterior se realizó basado en artículos originales, revisiones y guías clínicas

COVID­19 is caused by the SARS-CoV-2 virus, first described in December 2019 in Wuhan, China, and declared a global pandemic in March 2020. Currently there are various diagnostic methods for COVID-19, the gold standard is the detection of genetic material through polymerase chain reaction (PCR) in its variant, RT-PCR, which detects RNA-type genetic material present in the virus. However, it is necessary to have rapid tests with high sensitivity and precision to be performed on a large scale and provide timely diagnosis. Furthermore, other tools must be available, and although they will not establish the diagnosis, will allow the professional to provide better clinical and epidemiological management that will help predict the worsening of the patient and possible admission to the ICU. Among these, levels of D-dimer, lymphocytes, ferritin, urea and creatinine. In this review, the usefulness and limitations of the different diagnostic methods for COVID-19 are evaluated, as well as the characteristics, pathophysiology and immune response to SARS-CoV-2, and some important preanalytical aspects that allow minimizing diagnostic errors as a consequence of incorrect procedures in the collection, transport and conservation of the sample, that allow the professional to yield accurate and reliable results. This article was completed based on original articles, reviews and clinical guidelines

Inflammatory Response in COVID-19 Depending on the Severity of the Disease and the Vaccination Status.

The aim of this study was to analyze the serum concentration of interleukin-6 (IL-6), C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), ferritin, and procalcitonin in COVID-19 patients with different forms of the disease. We performed a prospective cohort study on 137 COVID-19 consecutive patients, divided into four groups according to the severity of the disease as follows: 30 patients in the mild form group, 49 in the moderate form group, 28 in the severe form group, and 30 in the critical form group. The tested parameters were correlated with COVID-19 severity. Significant differences were registered between the form of COVID-19 depending on the vaccination status, between LDH concentrations depending on the virus variant, and in IL-6, CRP, and ferritin concentrations and vaccination status depending on the gender. ROC analysis revealed that D-dimer best predicted COVID-19 severe forms and LDH predicted the virus variant. Our findings confirmed the interdependence relationships observed between inflammation markers in relation to the clinical severity of COVID-19, with all the tested biomarkers increasing in severe and critical COVID-19. IL-6, CRP, ferritin, LDH, and D-dimer were increased in all COVID-19 forms. These inflammatory markers were lower in Omicron-infected patients. The unvaccinated patients developed more severe forms compared to the vaccinated ones, and a higher proportion of them needed hospitalization. D-dimer could predict a severe form of COVID-19, while LDH could predict the virus variant.

A novel view of ferritin in cancer.

Since its discovery more than 85 years ago, ferritin has principally been known as an iron storage protein. However, new roles, beyond iron storage, are being uncovered. Novel processes involving ferritin such as ferritinophagy and ferroptosis and as a cellular iron delivery protein not only expand our thinking on the range of contributions of this protein but present an opportunity to target these pathways in cancers. The key question we focus on within this review is whether ferritin modulation represents a useful approach for treating cancers. We discussed novel functions and processes of this protein in cancers. We are not limiting this review to cell intrinsic modulation of ferritin in cancers, but also focus on its utility in the trojan horse approach in cancer therapeutics. The novel functions of ferritin as discussed herein realize the multiple roles of ferritin in cell biology that can be probed for therapeutic opportunities and further research.

COVID-19 compromises iron homeostasis: Transferrin as a target of investigation.

IMPORTANCE: Since the beginning of the COVID-19 pandemic, numerous metabolic alterations have been observed in individuals with this disease. It is known that SARS-CoV-2 can mimic the action of hepcidin, altering intracellular iron metabolism, but gaps remain in the understanding of possible outcomes in other pathways involved in the iron cycle. OBJECTIVE: To profile iron, ferritin and hepcidin levels and transferrin receptor gene expression in patients diagnosed with COVID-19 between June 2020 and September 2020. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study that evaluated iron metabolism markers in 427 participants, 218 with COVID-19 and 209 without the disease. EXPOSURES: The primary exposure was positive diagnose to COVID-19 in general population of Santo André and São Bernardo cities. The positive and negative diagnose were determinate through RT-qPCR. MAIN OUTCOMES AND MEASURES: Devido a evidências de alterações do ciclo do ferro em pacientes diagnosticados com COVID-19 e devido a corregulação entre hepcidina e receptor de transferrina, uma análise da expressão gênica deste último, poderia trazer insights sobre o estado de ferro celular. A hipótese foi confirmada, mostrando aumento da expressão de receptor de transferrina concomitante com redução do nível de hepcidina circulante. RESULTS: Serum iron presented lower values in individuals diagnosed with COVID-19, whereas serum ferritin presented much higher values in infected patients. Elderly subjects had lower serum iron levels and higher ferritin levels, and men with COVID-19 had higher ferritin values than women. Serum hepcidin was lower in the COVID-19 patient group and transferrin receptor gene expression was higher in the infected patient group compared to controls. CONCLUSIONS AND RELEVANCE: COVID-19 causes changes in several iron cycle pathways, with iron and ferritin levels being markers that reflect the state and evolution of infection, as well as the prognosis of the disease. The increased expression of the transferrin receptor gene suggests increased iron internalization and the mimicry of hepcidin action by SARS-CoV-2, reduces iron export via ferroportin, which would explain the low circulating levels of iron by intracellular trapping.

Hematological, Immunological, and Inflammation markers in Patients of COVID-19.

The present study was done to evaluate hematological, immunological, and inflammation markers in male and female patients infected with COVID-19, ranging from moderate to severe cases in Erbil city of Iraq. The study included 200 samples (60 male, and 60 female patients infected with COVID-19). While 40 healthy males and 40 healthy females were used as a control group. The results found significant differences in total white blood cells (WBC), lymphocytes, immunoglobin G (IgG), immunoglobin M (IgM), C-reactive protein (CRP), Ferritin, and erythrocyte sedimentation rate (ESR) between healthy control and patients infected with COVID-19 in males and females. Patients with COVID -19 showed a significantly p≤ 0.001 higher value of total WBC, IgG, IgM, CRP, Ferritin, and ESR when compared with the control group in both males and females. The percentage of lymphocytes in male and female patients is significantly p≤ 0.001  lower than that of the healthy control group. No significant differences in red blood cells (RBC), hemoglobin (Hb), hematocrit (HCT), and thrombocytes were observed between the control and patient groups in both males and females.

[Predictors of severe course of new coronavirus infection (COVID-19): study design].

AIM: To identify predictors of the severe course of a new coronavirus infection. MATERIALS AND METHODS: A retrospective analysis of 120 clinical case histories of patients hospitalized in hospitals in Tyumen with a confirmed diagnosis of COVID-19 within one year (01.08.2020-01.08.2021) was carried out. The patients were divided into two groups: 1st - with a favorable outcome (n=96), 2nd - with an unfavorable (fatal) outcome (n=24). For a more complete analysis, scales for assessing the clinical condition of patients (SHOCK-COVID), severity assessment (NEWS2) were used. Information processing was carried out in the IBM.SPSS.Statistics-19 program (USA). RESULTS: As a result of the study, the median age for the 1st group was significantly lower (58 years) than for patients of the 2nd group (69 years; p=0.029). A certain set of laboratory parameters for group 2 patients deviate significantly from the reference values (C-reactive protein - CRP - 7.6 [4.7; 15.2] mg/dl, D-dimer - 1.89 [1.36; 5.3] mcg/ml, ferritin - 605 [446.7; 792] ng/ml). When analyzed in groups, taking into account the main markers of the severity of the disease, using the V.Yu. Mareev CCAS-COVID (Clinical Condition Assessment Scale) scale, for the 1st group, the sum of the set of parameters was 6 [2; 7] points, which corresponds to the average severity of coronavirus infection, for the 2nd group 13 [9; 16] points - severe course. For patients of the 2nd group, a significant increase in the indicators of an unfavorable prognosis was revealed in comparison with the 1st group. CONCLUSION: Thus, in this study, the level of CRP, ferritin, D-dimer, the percentage of lung tissue damage according to computed tomography results, SaO2 were significantly associated with an unfavorable prognosis.

Interleukin-6 (IL-6) as a Predictor of Clinical Outcomes in Patients with COVID-19.

BACKGROUND: Interleukin-6 (IL-6) has been known to be involved in immune regulation, inflammatory response, and metabolism. It is also recognized as the major cause to underscore the pathology of severe COVID-19 patients. However, it remains to be seen if IL-6 is superior to other inflammatory biomarkers in ascertaining clinical severity and mortality rate for COVID-19. This study aimed to determine the value of IL-6 as a predictor of severity and mortality in COVID-19 patients and compare it with other pro-inflammatory biomarkers in the South Asian region. METHODS: An observational study was conducted, including all adult SARS-CoV-2 patients who had undergone IL-6 testing from December 2020 to June 2021. The patients' medical records were reviewed to collect demographic, clinical, and biochemical data. Other pro-inflammatory biomarkers apart from IL-6 included Neutrophils to Lymphocyte Ratio (NLR), D-dimer, C-reactive protein (CRP), ferritin, lactate dehydrogenase (LDH), and procal-citonin for analysis. SPSS version 22.0 was utilized. RESULTS: Out of the 393 patients who underwent IL-6 testing, 203 were included in the final analysis with a mean (SD) age of 61.9 years (12.9) and 70.9% (n = 144) were male. Fifty-six percent (n = 115) subjects had critical disease. IL-6 levels were elevated (> 7 pg/mL) in 160 (78.8%) patients. Levels of IL-6 significantly correlated with age, NLR, D-dimer, CRP, ferritin, LDH, length of stay, clinical severity, and mortality. All the inflammatory markers were significantly increased in critically ill and expired patients (p < 0.05). The receiver operator curve showed that IL-6 had the best area under the curve (0.898) compared to other pro-inflammatory biomarkers for mortality with comparable results for clinical severity. CONCLUSIONS: Study findings show that though IL-6 is an effective marker of inflammation and can be helpful for clinicians in recognizing patients with severe COVID-19. However, we still need further studies with larger sample size.

COVID-19 Biomarkers Comparison: Children, Adults and Elders.

Background and Objectives: this study aimed to research links between C-reactive protein (CRP), lactate dehydrogenase (LDH), creatinekinase (CK), 25-OH vitamin D (25-OHD), ferritin (FER), high-density lipoprotein cholesterol (HDL)cholesterol and clinical severity in patients from the western part of Romania, and compare their potential use as biomarkers for intensive care units (ICU) admission and death in children, adults and elders. Materials and Methods: this study is a retrospective cohort study, performed on patients positively diagnosed with COVID-19. Available CRP, LDH, CK 25-OH vitamin D, ferritin, HDL cholesterol and clinical severity were recorded. The following were assessed: median group differences, association, correlation and receiver operating characteristic. Results: 381 children, 614 adults and 381 elders were studied between 1 March 2021 and 1 March 2022. Most children and adults presented mild symptomatology (53.28%, 35.02%, respectively), while most elders presented severe symptomatology (30.04%). ICU admission was 3.67% for children, 13.19% for adults and 46.09% for elders, while mortality was 0.79% for children, 8.63% for adults and 25.1% for elders. With the exception of CK, all other biomarkers showed some significant associations with clinical severity, ICU admission and death. Conclusions: CRP, LDH, 25-OH vitamin D, ferritin and HDL are important biomarkers for COVID-19 positive patients, especially in the pediatric population, while CK was mostly within normal ranges.

Role of Serum Ferritin, D-Dimer, and C-Reactive Protein Parameters in COVID 19 Severity.

Following the epidemics caused by the transmission of the common virus between humans and animals (COVID-19), coronavirus 2 (SARS-CoV-2) is the third and most deadly strain of RNA virus that can cause respiratory, digestive, and nervous system problems, and there are many unknown complications. This study included 170 clinical samples of nasopharyngeal swaps (100 patients and 70 controls for both males and females). RT-PCR was performed, and blood samples were taken for biochemical analyses. They were obtained from Iraqi patients aged 25 to 92 years old. Between November 2021 and March 2022, COVID-19 patients were admitted to Dar al-salam Hospital, Alyarmok Teaching Hospital, and Alshefaa Hospital. AFIAS D-Dimer, AFIAS ferritin, and NycoCard CRP tests were performed on the patients and were classified depending on the severity of their infection (mild or moderate, severe and critical). The results showed a significant increase in ferritin in critically ill patients (545.58 ± 57.71). A significant increase of D-dimer was found with different severity with highly significant in the critical group (3.93 ± 0.79). With varying degrees of severity, a substantial rise in CRP was discovered with highly significant in the critical group (96.27 ± 14.55) between the severity group (p-value <0.001). Also, COVID-19 individuals in the age range (50 - 60) tended to be more severe than younger people, whereas the effect of gender is not significant in any patient group. The biochemical factors, including D-Dimer, ferritin, and CRP, are effective in the disease's occurrence of symptoms and severity.

Cross-sectional study to describe the severity, bio-chemical associations, and final outcomes of COVID-19-associated rhino-orbital-cerebral mucormycosis in a tertiary hospital of East India.

Purpose: The second wave of coronavirus disease 2019 (COVID-19) pandemic triggered a mucormycosis epidemic in India. Diabetes mellitus and dysregulated immune response were contributors, and rhino-orbital-cerebral mucormycosis (ROCM) was the most common presentation. It is however not known whether bio-chemical parameters at presentation correlate with stage of ROCM or final outcome in terms of vision or mortality. Methods: This retrospective, hospital-based study included all in-patients of mucormycosis with ophthalmic manifestations at presentation admitted during June 1, 2021 to August 31, 2021. It aimed to evaluate the association between severity of infection, serum levels of HbA1c, ferritin, interleukin-6 (IL-6), C-reactive protein (CRP), and D-dimer levels at presentation and outcome. Results: There were altogether 47 eligible cases having a mean age of 48.8 ± 10.9 years with a male:female ratio of 2.6:1; forty-two (89.4%) had pre-existing diabetes, and five (10.6%) had steroid-induced hyperglycemia. The mean HbA1c among diabetics was 9.7 ± 2.1. HbA1c and serum CRP showed an increase over subsequent stages, which was not statistically significant (P = 0.31). IL-6 values for all stages were similar (P = 0.97). Only serum ferritin levels showed a statistically significant increase over stages (P = 0.04). IL-6 was significantly lower (P = 0.03) in patients who survived, whereas CRP levels were significantly lower in patients who had final visual acuity (VA) better than only perception of light (P = 0.03). Conclusion: Uncontrolled diabetes mellitus is a significant association of ROCM. Serum ferritin levels at presentation best correlate with extent of the disease. CRP levels are best to prognosticate cases that will have sufficient VA to carry on activities of daily living, whereas IL-6 levels are best associated with survival.

Iron as a therapeutic target in chronic liver disease.

It was clearly realized more than 50 years ago that iron deposition in the liver may be a critical factor in the development and progression of liver disease. The recent clarification of ferroptosis as a specific form of regulated hepatocyte death different from apoptosis and the description of ferritinophagy as a specific variation of autophagy prompted detailed investigations on the association of iron and the liver. In this review, we will present a brief discussion of iron absorption and handling by the liver with emphasis on the role of liver macrophages and the significance of the iron regulators hepcidin, transferrin, and ferritin in iron homeostasis. The regulation of ferroptosis by endogenous and exogenous mod-ulators will be examined. Furthermore, the involvement of iron and ferroptosis in various liver diseases including alcoholic and non-alcoholic liver disease, chronic hepatitis B and C, liver fibrosis, and hepatocellular carcinoma (HCC) will be analyzed. Finally, experimental and clinical results following interventions to reduce iron deposition and the promising manipulation of ferroptosis will be presented. Most liver diseases will be benefited by ferroptosis inhibition using exogenous inhibitors with the notable exception of HCC, where induction of ferroptosis is the desired effect. Current evidence mostly stems from in vitro and in vivo experimental studies and the need for well-designed future clinical trials is warranted.

Longitudinal profiles of plasma gelsolin, cytokines and antibody expression predict COVID-19 severity and hospitalization outcomes.

Background: Prognostic markers for COVID-19 disease outcome are currently lacking. Plasma gelsolin (pGSN) is an actin-binding protein and an innate immune marker involved in disease pathogenesis and viral infections. Here, we demonstrate the utility of pGSN as a prognostic marker for COVID-19 disease outcome; a test performance that is significantly improved when combined with cytokines and antibodies compared to other conventional markers such as CRP and ferritin. Methods: Blood samples were longitudinally collected from hospitalized COVID-19 patients as well as COVID-19 negative controls and the levels of pGSN in µg/mL, cytokines and anti- SARS-CoV-2 spike protein antibodies assayed. Mean ± SEM values were correlated with clinical parameters to develop a prognostic platform. Results: pGSN levels were significantly reduced in COVID-19 patients compared to healthy individuals. Additionally, pGSN levels combined with plasma IL-6, IP-10 and M-CSF significantly distinguished COVID-19 patients from healthy individuals. While pGSN and anti-spike IgG titers together strongly predict COVID-19 severity and death, the combination of pGSN and IL-6 was a significant predictor of milder disease and favorable outcomes. Conclusion: Taken together, these findings suggest that multi-parameter analysis of pGSN, cytokines and antibodies could predict COVID-19 hospitalization outcomes with greater certainty compared with conventional clinical laboratory markers such as CRP and ferritin. This research will inform and improve clinical management and health system interventions in response to SARS-CoV-2 infection.

Central Retinal Artery Occlusion in Rhino-Orbital-Cerebral Mucormycosis: An Inflammatory-Prothrombotic State.

PURPOSE: The aim was to evaluate patient profiles of rhino-orbital-cerebral mucormycosis (ROCM) cases with central retinal artery occlusion (CRAO) postcoronavirus disease 2019. DESIGN: A nonrandomized retrospective case-control study. METHODS: The ROCM cases presenting with CRAO were compared with a control ROCM group without CRAO at a tertiary care center. Demography, systemic status, clinical features, histopathology, imaging, and blood profile were assessed for any specific risk factors. RESULTS: A total of 12 patients were seen in the CRAO group and 16 in the non-CRAO group. The male-to-female ratio was 3:1 with a mean age of 49.5 years. In the CRAO group, 75% had diabetes mellitus with mean hemoglobin A1c of 9.03%, and 66.7% had received steroid treatment. All cases were histopathologically confirmed positive for mucor. There was a significant difference in mean D-dimer and serum ferritin between the 2 groups, with higher level in the CRAO group. All patients with CRAO had light perception-negative vision, with total ophthalmoplegia and proptosis seen in 66.7% of cases. Four patients had orbital apex involvement, 5 had cavernous sinus involvement, and 8 had intracranial involvement in the CRAO group. CONCLUSIONS: Inflammatory markers D-dimer and serum ferritin were significantly associated with CRAO, suggestive of hyperinflammatory and hypercoagulable state. A high index of suspicion should be maintained in cases with elevated markers and prophylactic anticoagulants can be started to prevent CRAO in a subset of patients.

Cardiac magnetic resonance T2* mapping in patients with COVID-19 pneumonia is associated with serum ferritin level?

The coronavirus disease of 2019 (COVID-19)-related myocardial injury is an increasingly recognized complication and cardiac magnetic resonance imaging (MRI) has become the most commonly used non-invasive imaging technique for myocardial involvement. This study aims to assess myocardial structure by T2*-mapping which is a non-invasive gold-standard imaging tool for the assessment of cardiac iron deposition in patients with COVID-19 pneumonia without significant cardiac symptoms. Twenty-five patients with COVID-19 pneumonia and 20 healthy subjects were prospectively enrolled.Cardiac volume and function parameters, myocardial native-T1, and T2*-mapping were measured. The association of serum ferritin level and myocardial mapping was analyzed. There was no difference in terms of cardiac volume and function parameters. The T2*-mapping values were lower in patients with COVID-19 compared to controls (35.37 [IQR 31.67-41.20] ms vs. 43.98 [IQR 41.97-46.88] ms; p < 0.0001), while no significant difference was found in terms of native-T1 mapping value(p = 0.701). There was a positive correlation with T2*mapping and native-T1 mapping values (r = 0.522, p = 0.007) and negative correlation with serum ferritin values (r = - 0.653, p = 0.000), while no correlation between cardiac native-T1 mapping and serum ferritin level. Negative correlation between serum ferritin level and T2*-mapping values in COVID-19 patients may provide a non-contrast-enhanced alternative to assess tissue structural changes in patients with COVID-19. T2*-mapping may provide a non-contrast-enhanced alternative to assess tissue alterations in patients with COVID-19. Adding T2*-mapping cardiac MRI in patients with myocardial pathologies would improve the revealing of underlying mechanisms. Further in vivo and ex vivo animal or human studies designed with larger patient cohorts should be planned.

Variation in biochemical parameters in COVID-19 patients admitted at a tertiary care dedicated COVID hospital: A prospective study.

Introduction: COVID-19 infection has a myriad of presentation. Rural India and other developing nations are relatively resource poor, not having access to modern specialized investigations. In this study, we tried to evaluate only biochemical parameters in predicting the severity of the infection. The aim of this study was to find a cost-effective means to predict the clinical course at the time of admission and thereby to reduce mortality and, if possible, morbidity by timely intervention. Materials and Methods: All COVID-19-positive cases admitted at our hospital from March 21 to December 31, 2020, were recruited in this study. The same acted as sham control at recovery. Results: We observed a significant difference in biochemical parameters at the time of admission and discharge, between mild/moderate disease and severe disease. We found slightly deranged liver function tests at admission, which becomes normal at the time of discharge. Urea, C-reactive protein (CRP), procalcitonin, lactate dehydrogenase, and ferritin concentrations in severe/critical patients were significantly higher than that in the mild/moderate group. Receiver operating characteristic curves were plotted to predict the severity on the basis of biochemical parameters independently, of the patients based on these values. Conclusion: We proposed cutoff values of certain biochemical parameters, which will help in judging the severity of the infection at admission. We developed a predictive model with a significant predictive capability for CRP and ferritin values, using normal available biochemical parameters, routinely done in resource-poor centers. Clinicians working in resource-poor situations will be benefitted by having an idea of the severity of the disease. Timely intervention will reduce mortality and severe morbidity.

Résumé Introduction: L'infection au COVID19 a une myriade de présentations. L'Inde rurale et d'autres pays en développement sont relativement pauvres en ressources, non avoir accès aux enquêtes spécialisées modernes. Dans cette étude, nous avons essayé d'évaluer uniquement les paramètres biochimiques pour prédire la gravité de l'infection. Le but de cette étude était de trouver un moyen rentable de prédire l'évolution clinique au moment de l'admission et ainsi de réduire la mortalité et, si possible, la morbidité par une intervention rapide. Matériels et méthodes: Tous les cas positifs au COVID19 admis à notre hospitalisés du 21 mars au 31 décembre 2020, ont été recrutés dans cette étude. La même chose a agi comme un contrôle factice lors de la récupération. Résultats: Nous avons observé une différence significative dans les paramètres biochimiques au moment de l'admission et de la sortie, entre une maladie légère/modérée et une maladie grave. Nous avons trouvé des tests de la fonction hépatique légèrement dérangés à l'admission, qui deviennent normaux au moment de la sortie. Urée, protéine Créactive (CRP, les concentrations de procalcitonine, de lactate déshydrogénase et de ferritine chez les patients sévères/critiques étaient significativement plus élevées que chez les patients légers/modérés groupe. Les courbes caractéristiques de fonctionnement du récepteur ont été tracées pour prédire la gravité sur la base de paramètres biochimiques indépendamment, deles patients en fonction de ces valeurs. Conclusion: Nous avons proposé des valeurs seuils de certains paramètres biochimiques, qui permettront de juger de la gravité de l'infection à l'admission. Nous avons développé un modèle prédictif avec une capacité prédictive significative pour les valeurs de CRP et de ferritine, en utilisant les paramètres biochimiques normaux disponibles, systématiquement effectués dans les centres pauvres en ressources. Les cliniciens travaillant dans des situations où les ressources sont limitées bénéficier d'avoir une idée de la gravité de la maladie. Une intervention rapide réduira la mortalité et la morbidité grave. Mots-clés: COVID19, ferritine, lactate déshydrogénase, urée.

A ferritin-based COVID-19 nanoparticle vaccine that elicits robust, durable, broad-spectrum neutralizing antisera in non-human primates.

While the rapid development of COVID-19 vaccines has been a scientific triumph, the need remains for a globally available vaccine that provides longer-lasting immunity against present and future SARS-CoV-2 variants of concern (VOCs). Here, we describe DCFHP, a ferritin-based, protein-nanoparticle vaccine candidate that, when formulated with aluminum hydroxide as the sole adjuvant (DCFHP-alum), elicits potent and durable neutralizing antisera in non-human primates against known VOCs, including Omicron BQ.1, as well as against SARS-CoV-1. Following a booster ~one year after the initial immunization, DCFHP-alum elicits a robust anamnestic response. To enable global accessibility, we generated a cell line that can enable production of thousands of vaccine doses per liter of cell culture and show that DCFHP-alum maintains potency for at least 14 days at temperatures exceeding standard room temperature. DCFHP-alum has potential as a once-yearly (or less frequent) booster vaccine, and as a primary vaccine for pediatric use including in infants.

Effective Multivalent Oriented Presentation of Meningococcal NadA Antigen Trimers by Self-Assembling Ferritin Nanoparticles.

The presentation of viral antigens on nanoparticles in multivalent arrays has emerged as a valuable technology for vaccines. On the nanoparticle surface, highly ordered, repetitive arrays of antigens can mimic their geometric arrangement on virion surfaces and elicit stronger humoral responses than soluble viral antigens. More recently, bacterial antigens have been presented on self-assembling protein nanoparticles and have elicited protective antibody and effective T-helper responses, further supporting the nanoparticle platform as a universal approach for stimulating potent immunogenicity. Here, we present the rational design, structural analysis, and immunogenicity of self-assembling ferritin nanoparticles displaying eight copies of the Neisseria meningitidis trimeric adhesin NadA. We engineered constructs consisting of two different NadA fragments, head only and head with stalk, that we fused to ferritin and expressed in Escherichia coli. Both fusion constructs self-assembled into the expected nanoparticles as determined by Cryo electron microscopy. In mice, the two nanoparticles elicited comparable NadA antibody levels that were 10- to 100-fold higher than those elicited by the corresponding NadA trimer subunits. Further, the NadAferritin nanoparticles potently induced complement-mediated serum bactericidal activity. These findings confirm the value of self-assembling nanoparticles for optimizing the immunogenicity of bacterial antigens and support the broad applicability of the approach to vaccine programs, especially for the presentation of trimeric antigens.

In the SARS-CoV-2 Pandora Pandemic: Can the Stance of Premorbid Intestinal Innate Immune System as Measured by Fecal Adnab-9 Binding of p87:Blood Ferritin, Yielding the FERAD Ratio, Predict COVID-19 Susceptibility and Survival in a Prospective Population Database?

SARS-CoV-2 severity predictions are feasible, though individual susceptibility is not. The latter prediction allows for planning vaccination strategies and the quarantine of vulnerable targets. Ironically, the innate immune response (InImS) is both an antiviral defense and the potential cause of adverse immune outcomes. The competition for iron has been recognized between both the immune system and invading pathogens and expressed in a ratio of ferritin divided by p87 (as defined by the Adnab-9 ELISA stool-binding optical density, minus the background), known as the FERAD ratio. Associations with the FERAD ratio may allow predictive modeling for the susceptibility and severity of disease. We evaluated other potential COVID-19 biomarkers prospectively. Patients with PCR+ COVID-19 tests (Group 1; n = 28) were compared to three other groups. In Group 2 (n = 36), and 13 patients displayed COVID-19-like symptoms but had negative PCR or negative antibody tests. Group 3 (n = 90) had no symptoms and were negative when routinely PCR-tested before medical procedures. Group 4 (n = 2129) comprised a pool of patients who had stool tests and symptoms, but their COVID-19 diagnoses were unknown; therefore, they were chosen to represent the general population. Twenty percent of the Group 4 patients (n = 432) had sufficient data to calculate their FERAD ratios, which were inversely correlated with the risk of COVID-19 in the future. In a case report of a neonate, we studied three biomarkers implicated in COVID-19, including p87, Src (cellular-p60-sarcoma antigen), and Abl (ABL-proto-oncogene 2). The InImS of the first two were positively correlated. An inverse correlation was found between ferritin and lysozyme in serum (p < 0.05), suggesting that iron could have impaired an important innate immune system anti-viral effector and could partially explain future COVID-19 susceptibility.

COVID-19 severity appears to be reduced in spring/summer.

BACKGROUND: because of different human behaviours, SARS-CoV-2 spread may be lower in spring/summer. On the contrary, it is not clearly known whether the clinical course/severity of hospitalized patients infected by SARS-CoV-2 can be different in the various seasons.. OBJECTIVES: to understand whether there were differences in severity of COVID-19 in patients who had contracted the infection in winter versus those infected in spring/summer. DESIGN: observational retrospective cohort study. SETTING AND PARTICIPANTS: from the administrative database of the SARS-CoV-2 surveillance system and that of hospital discharge, a cohort of patients (8,221, 653 of which were hospitalized) who tested positive to the RT-PCR test for SARS-CoV-2 between 01.12.2020 and 31.07.2021 in the Grosseto province (Tuscany Region, Central Italy) was selected and analysed. MAIN OUTCOME MEASURES: hospitalization rate and length, continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) use, Intensive Care Unite (ICU) admissions, intra-hospital mortality and PaO2/FiO2 values were measured and compared between subjects infected in winter and those who developed COVID-19 in spring/summer. Viral load (cycle threshold, Ct), vitamin D, serum ferritin, IL-6, procalcitonin, D-dimer, and C-reactive protein measured in the two periods were also compared. RESULTS: in the considered months, the hospitalization rate among 8,221 patients with COVID-19 was 8%: 370 (8.5%) individuals were hospitalized in winter and 283 (7,3%; p=0.31) in spring/summer; 62 (16.8%), 88 (23.8%), and 63 (17%) in winter and 28 (9.9%), 40 (14.1%), and 36 (12.7%) in spring/summer were admitted in ICU (p=0.01), used CPAP/NIV (p=0.002) and died (p=0.13), respectively. Hospitalization days were 14.5±11.6 in winter and 10.3±8.84 in spring/summer (p=0.001), while minimum PaO2/FiO2, measured during hospital stays was 123.2±38.6 in spring/summer and 112.6±40.8 in winter (p=0.054). Multivariate analysis (adjusted for all confounding factors) also confirmed reduced risks of having ICU admissions (0.53; 95%CI 0.32;0.88; p=0.01) and of using CPAP/NIV (0.48; 95%CI 0.32;0.75; p=0.001) in spring/summer when compared to winter. Hospitalization days and minimum PaO2/FiO2 were also lower in spring/summer (ß= -3.9; 95%CI -5.5;-2.2; p=0.001) and winter (ß= -17; 95%CI -0.93;35; p=0.06), respectively. The adjusted hazard ratio of mortality in winter, obtained with a Cox model, was higher of about 38% compared to spring/summer. No Ct values (viral load) differences were found either in winter (19.45±6.18) or spring/summer (20.3±6.7; p=0.343). IL-6, ferritin, procalcitonin, D-dimer were similar. Conversely, CRP was lower whereas vitamin D was higher in the warmer seasons. CONCLUSIONS: COVID-19 may be less severe during spring/summer in hospitalized patients. This does not seem to be influenced by different SARS-CoV-2 viral load in the different periods considered. C-reactive protein was found to be lower whereas vitamin D higher in the warmer months. It can be hypothesized that higher levels of vitamin D in spring/summer, compared to winter, may be associated to a positive modulation of COVID-19 induced inflammation with a possible disease severity reduction during spring/summer.