Initial Phase Of Infection Research Articles

Designing and evaluating a novel blood-brain barrier in vitro model of teleost for reproducing alterations in brain infecting

A new blood-brain barrier (BBB) in vitro model of tilapia (Oreochromis niloticus) was successfully established by co-culture with brain microvascular endothelial cell line TVEC-01 and brain astrocyte cell line TA-02 of tilapia. Experiments with the expression levels of BBB-related genes, TEER value detection and four-hour water-leaking test have shown that the BBB in vitro model has an excellent barrier effect. In bacterial penetration experiments, the pathogenic strain of Streptococcus agalactiae was able to pass through the BBB in vitro model and initiate a series of immune responses, among which TA-02 contributed to the expression of pro-inflammatory cytokines and TVEC-01 contributed to the expression of anti-inflammatory cytokines, providing an excellent research tool and theoretical basis for further study of meningitis. Moreover, the qRT-PCR and transmission electron microscopy revealed that the pathogenic strain of S. agalactiae effectively penetrated the BBB in vitro model of tilapia during early-stage infection without destroying tight junction integrity. This suggested that, in the initial phases of infection, the pathogenic strain of S. agalactiae may breach the BBB via a transcellular pathway rather than a paracellular pathway. Summarily, a novel BBB in vitro model of tilapia was successfully designed and evaluated for reproducing alterations in brain infecting.

Dual RNA-Seq Unveils Candidate Key Virulence Genes of Vibrio harveyi at the Early Stage of Infection in Hybrid Grouper (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus).

Vibrio harveyi is a major bacterial pathogen that causes disease in aquaculture animals worldwide. Although V. harveyi consistently harbors a range of traditional virulence genes, it remains unclear which specific genes are crucial for virulence at different infection stages. Dual RNA-seq is a cutting-edge RNA sequencing technology that is ideal for investigating the gene expression patterns of pathogens within the host, which is highly effective in identifying key virulence genes. In previous artificial infection experiments, we have identified the liver of hybrid grouper (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus) as the main target organ for pathogenic V. harveyi GDH11385 during the initial infection phase. To further explore the key virulence factors of V. harveyi at the early stage of infection, the liver of the hybrid grouper infected with strain GDH11385 was analyzed here by dual RNA-seq. The transcriptome data were compared with that of in vitro cultured bacteria. The results showed that 326 and 1140 DEGs (differentially expressed genes) were significantly up- and down-regulated, respectively, at 4 h post-infection (hpi). Further pathway enrichment analyses revealed that these up-regulated DEGs in vivo were mainly enriched in siderophore biosynthesis and transport, type VI secretion system (T6SS), flagellar assembly, glycolysis/gluconeogenesis, and ribosome. Notably, all genes involved in the metabolism and utilization of vibrioferrin (a carboxylate class of siderophore produced by Vibrio), and most of the genes within one of three T6SSs, were significantly up-regulated in vivo. This indicates that siderophore-dependent iron competition and T6SS-mediated delivery of virulence factors are vital for the successful colonization of V. harveyi at the early stage of infection. This study provides more precise clues to reveal the virulence mechanism of V. harveyi during the initial phase of infection.

Entomopathogenic potential of indigenous Simplicillium subtropicum (Hypocreales: Cordycipitaceae) isolates from Tamil Nadu, India, against the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae)

BackgroundAphis gossypii Glover (Hemiptera: Aphididae) is an economically important polyphagous pest species infesting many agricultural and horticultural crops causing severe yield losses. In order to develop biopesticides for the management of aphids in an environmentally safe manner, 6 indigenous entomopathogenic fungi Simplicillium subtropicum were isolated from soils of Tamil Nadu and their pathogenicity was tested against A. gossypii under laboratory conditions after characterization.ResultsPhenotypic and molecular characterization was performed for all the isolates for species identification. Results of the pathogenicity test showed that the isolate S6 (PP446637) performed well among other isolates causing 58.33% mortality on 7 days after treatment (DAT) @ 1 × 108 spores/ml. The LC50 and LT50 values were found to be 2.36 × 107 spores/ml at 7 DAT and 160.20 h @ 1 × 108 spores/ml, respectively. SEM images of A. gossypii treated with the isolate S6 (PP446637) revealed that initial phase of infection, i.e., adhesion, formation of germ tube and appressoria starts within 24 h post-infection (hpi), hyphal development and penetration of cuticle occurred within 48 hpi and extrusion of mycelium and conidiogenesis occurred within 72 hpi.ConclusionThis study reveals the entomopathogenic potential of indigenous S. subtropicum isolates against A. gossypii and suggests their use for the eco-friendly management of aphids.

Mouse polyomavirus infection induces lamin reorganisation.

The nuclear lamina is a dense network of intermediate filaments beneath the inner nuclear membrane. Composed of A-type lamins (lamin A/C) and B-type lamins (lamins B1 and B2), the nuclear lamina provides a scaffold for the nuclear envelope and chromatin, thereby maintaining the structural integrity of the nucleus. A-type lamins are also found inside the nucleus where they interact with chromatin and participate in gene regulation. Viruses replicating in the cell nucleus have to overcome the nuclear envelope during the initial phase of infection and during the nuclear egress of viral progeny. Here, we focused on the role of lamins in the replication cycle of a dsDNA virus, mouse polyomavirus. We detected accumulation of the major capsid protein VP1 at the nuclear periphery, defects in nuclear lamina staining and different lamin A/C phosphorylation patterns in the late phase of mouse polyomavirus infection, but the nuclear envelope remained intact. An absence of lamin A/C did not affect the formation of replication complexes but did slow virus propagation. Based on our findings, we propose that the nuclear lamina is a scaffold for replication complex formation and that lamin A/C has a crucial role in the early phases of infection with mouse polyomavirus.

Analysis of Plant and Fungal Transcripts from Resistant and Susceptible Phenotypes of Leptospermum scoparium Challenged by Austropuccinia psidii.

Austropuccinia psidii is the causal pathogen of myrtle rust disease of Myrtaceae. To gain understanding of the initial infection process, gene expression in germinating A. psidii urediniospores and in Leptospermum scoparium-inoculated leaves were investigated via analyses of RNA sequencing samples taken 24 and 48 h postinoculation (hpi). Principal component analyses of transformed transcript count data revealed differential gene expression between the uninoculated L. scoparium control plants that correlated with the three plant leaf resistance phenotypes (immunity, hypersensitive response, and susceptibility). Gene expression in the immune resistant plants did not significantly change in response to fungal inoculation, whereas susceptible plants showed differential expression of genes in response to fungal challenge. A putative disease resistance gene, jg24539.t1, was identified in the L. scoparium hypersensitive response phenotype family. Expression of this gene may be associated with the phenotype and could be important for further understanding the plant hypersensitive response to A. psidii challenge. Differential expression of pathogen genes was found between samples taken 24 and 48 hpi, but there were no significant differences in pathogen gene expression that were associated with the three different plant leaf resistance phenotypes. There was a significant decrease in the abundance of fungal transcripts encoding three putative effectors and a putative carbohydrate-active enzyme between 24 and 48 hpi, suggesting that the encoded proteins are important during the initial phase of infection. These transcripts, or their translated proteins, may be potential targets to impede the early phases of fungal infection by this wide-host-range obligate biotrophic basidiomycete.

Analysis of Cultured Gut Microbiota Using MALDI-TOF MS in COVID-19 Patients from Serbia during the Predominance of the SARS-CoV-2 Omicron Variant.

The currently dominant SARS-CoV-2 omicron variant, while causing mild respiratory symptoms, exhibits high transmissibility, drug resistance, and immune evasion. We investigated whether the presence of the SARS-CoV-2 affected the dynamics of fecal microbial composition isolated in culture in moderate COVID-19 patients. Blood, stool, and medical records were collected from 50 patients with confirmed SARS-CoV-2 infection. Two samples were taken per patient, at disease onset (within 5 days) and after symptom resolution (30-35 days). The part of the gut microbiota identifiable using MALDI-TOF MS was analyzed, and inflammatory cytokines and blood markers were measured in serum. The analysis identified 566 isolates at the species level, including 83 bacterial and 9 fungal species. Our findings indicate a change in the gut microbiota composition isolated in culture during the initial phase of infection, characterized by the proliferation of opportunistic bacteria such as Enterococcus spp. and Citrobacter spp., at the expense of beneficial commensal bacteria from the genus Bacillus and Lactobacillus. Additionally, the enrichment of fungal pathogens in fecal samples collected 30 days after the cessation of disease symptoms might suggest a prolonged disruption of the gut microbiota even after the resolution of COVID-19 symptoms. This study contributes to a growing body of evidence on the systemic effects of SARS-CoV-2 and highlights the importance of considering gastrointestinal involvement in the management and treatment of COVID-19.

Regulation of host metabolism and defense strategies to survive neonatal infection

Two distinct defense strategies, disease resistance (DR) and disease tolerance (DT), enable a host to survive infectious diseases. Newborns, constrained by limited energy reserves, predominantly rely on DT to cope with infection. However, this approach may fail when pathogen levels surpass a critical threshold, prompting a shift to DR that can lead to dysregulated immune responses and sepsis. The mechanisms governing the interplay between DR and DT in newborns remain poorly understood. Here, we compare metabolic traits and defense strategies between survivors and non-survivors in Staphylococcus epidermidis (S. epidermidis)-infected preterm piglets, mimicking infection in preterm infants. Compared to non-survivors, survivors displayed elevated DR during the initial phase of infection, followed by stronger DT in later stages. In contrast, non-survivors showed clear signs of respiratory and metabolic acidosis and hyperglycemia, together with exaggerated inflammation and organ dysfunctions. Hepatic transcriptomics revealed a strong association between the DT phenotype and heightened oxidative phosphorylation in survivors, coupled with suppressed glycolysis and immune signaling. Plasma metabolomics confirmed the findings of metabolic regulations associated with DT phenotype in survivors. Our study suggests a significant association between the initial DR and subsequent DT, which collectively contributes to improved infection survival. The regulation of metabolic processes that optimize the timing and balance between DR and DT holds significant potential for developing novel therapeutic strategies for neonatal infection.

Susceptibility and host immune response comparison between Siniperca chuatsi and Siniperca scherzeri infected by Aeromonas veronii

The bacterial hemorrhagic septicemia caused by Aeromonas veronii is a highly contagious disease leading to high mortality in various aquatic animals, which has become one of the most serious diseases in mandarin fish, Siniperca chuatsi and Siniperca scherzeri. The difference of susceptibility and host immune response between S. chuatsi and S. scherzeri to A. veronii has not been revealed. In this study, the calculated LD50 of A. veronii SJ4 to S. chuatsi and S. scherzeri was 3.8 × 105 CFU/ mL and 4.8 × 106 CFU/mL, respectively, indicating S. chuatsi displays more susceptible to A. veronii than S. scherzeri. The differences of immune response between S. chuatsi and S. scherzeri infected by A. veronii SJ4 was analyzed by transcriptome technology. A total of 6010 and 1676 differentially expressed genes (DEGs) of kidneys were detected in the S. scherzeri experimental group (S-S-E/C) and S. chuatsi experimental group (S-C-E/C) at the 12 hpi, respectively. GO and KEGG functional analysis of DEGs indicated that numerous enriched immune terms were mainly related to antigen processing and presentation, toll-like receptor signaling, and C-type lectin receptor signaling. 8 DEGs (CLE, HSP90, IL6, MHC I, MHC II, RAS, TLR5 and TLR9) were selected from these immune related pathways, and the spatiotemporal expression of these DEGs in S. chuatsi and S. scherzeri were evaluated and compared. The results showed that CLE, HSP90, IL6, MHC I, MHC II, RAS, TLR5 and TLR9 in S. scherzeri after A. veronii infection were significantly up-regulated than in S. chuatsi. Our results indicated that these immune-related genes may exert a pivotal role during the initial phase of infection, and the priming speed of these immune-related genes lead to the differences in host immunity. This study screened the potential genes and pathways which involved in the immune response of mandarin fish, which helps for further understanding on fish immune. By selecting immune-related genes and comparing the immune mechanisms of S. chuatsi and S. scherzeri at the transcriptome level, the research offers new insights for the genetic breeding of Siniperca species to enhance infection resistance.

The global clinical studies of long COVID

People with long COVID are those who still have symptoms, signs, and conditions after the initial phase of infection of SARS-CoV-2. The incidence of long COVID varies among regions—31% in North America, 44% in Europe, and 51% in Asia, which is challenging the healthcare system, but there is limited guidelines for its treatment. With more and more nationwide projects funded by the government such as the RECOVER initiative in the United States and National Institute for Health Research funding in the United Kingdom, an increasing number of ongoing clinical trials are investigating the efficacy of diverse therapies on reversing long COVID. After searching the World Health Organization International Clinical Trial Registry Platform, 587 clinical studies are identified as long COVID studies. Among these, 312 studies (53.2%) are testing potential therapies. Most of the long COVID trials were conducted in the United States (58 trials [18.6%]), followed by India (55 trials [17.6%]), and Spain (20 trials [6.4%]). Interventions in these clinical trials include physical exercise, rehabilitation therapy, behavioral therapy, and pharmacological therapies including herbs, paxlovid, and fluvoxamine. These trials are aiming to deal with these long COVID symptoms and signs including fatigue, decreased pulmonary function, reduced cognitive function, and others. To date, only 11 of these 312 studies have published their results that were not confirmative, unfortunately. Future studies should be designed to address sleep disorders which were seldomly included in registered clinical studies. Moreover, interventions aimed at treating the underlying pathophysiology of long COVID are also necessary but currently lacking.

Clinical phenotype of anaerobic bacteremia unaccompanied by detectable abscess lesion: a 10-year retrospective, multicenter, observational-cohort study.

Despite the importance of abscess lesions in clinical decisions regarding anaerobic bacteremia (AB), their impact on clinical characteristics remains unclear. Herein, we aimed to elucidate the clinical factors associated with AB that were unaccompanied by detectable abscess lesions during the initial phase of infection. This was a multicenter retrospective observational study involving patients with culture-proven AB at six tertiary hospitals in Japan between January 2012 and March 2022. Data on clinical characteristics, laboratory and radiological findings were collected, and their associations with the absence of detectable abscess lesions were analyzed. In total, 393 participants were included. Abscess lesions were absent in 42.7% of the entire cohort and detectable in the remaining patients. No differences were identified in the malignancy, severity, or 30-day mortality between patients with and without detectable abscess lesions. Multivariate logistic regression analysis adjusted for age and the modified Charlson comorbidity score revealed that the immunosuppressive status (febrile neutropenia or corticosteroid use), C-reactive protein (CRP) level ≤9.8mg/dL at onset, and the presence of gram-positive anaerobic rods (GPARs) were independently associated with AB unaccompanied by detectable abscess lesions [odds ratios (ORs) 3.24, 3.00, and 2.81, respectively; p<0.05]. This study elucidated distinctive clinical and microbiological characteristics of AB unaccompanied by detectable abscess lesions, with relatively lower CRP elevation, immunosuppressive status, and GPARs as the causative anaerobes.

Evolutionary trends of respiratory syncytial viruses: Insights from large-scale surveillance and molecular dynamics of G glycoprotein

Human respiratory syncytial virus (RSV) is an underlying cause of lower respiratory illnesses in children, elderly and immunocompromised adults. RSV contains multiple structural and non-structural proteins with two major glycoproteins that control the initial phase of infection, fusion glycoprotein and the attachment (G) glycoprotein. G protein attaches to the ciliated cells of airways initiating the infection. The hypervariable G protein plays a vital role in evolution of RSV strains. We employed multiple bioinformatics tools on systematically accessed large-scale data to evaluate mutations, evolutionary history, and phylodynamics of RSV. Mutational analysis of central conserved region (CCR) on G protein-coding sequences between 163 and 189 positions revealed frequent mutations at site 178 in human RSV (hRSV) A while arginine to glutamine substitutions at site 180 positions in hRSV B, remained prevalent from 2009 to 2014. Phylogenetic analysis indicates multiple signature mutations within G protein responsible for diversification of clades. The USA and China have highest number of surveillance records, followed by Kenya. Markov Chain Monte Carlo Bayesian skyline plot revealed that RSV A evolved steadily from 1990 to 2000, and rapidly between 2003 and 2005. Evolution of RSV B continued from 2003 to 2022, with a high evolution stage from 2016 to 2020. Throughout evolution, cysteine residues maintained their strict conserved states while CCR has an entropy value of 0.0039(±0.0005). This study concludes the notion that RSV G glycoprotein is continuously evolving while the CCR region of G protein maintains its conserved state providing an opportunity for CCR-specific monoclonal antibodys (mAbs) and inhibitors as potential candidates for immunoprophylaxis.

The Role of Cytokines and Molecular Pathways in Lung Fibrosis Following SARS-CoV-2 Infection: A Physiopathologic (Re)view.

SARS-CoV-2 infection is a significant health concern that needs to be addressed not only during the initial phase of infection but also after hospitalization. This is the consequence of the various pathologies associated with long COVID-19, which are still being studied and researched. Lung fibrosis is an important complication after COVID-19, found in up to 71% of patients after discharge. Our research is based on scientific articles indexed in PubMed; in the selection process, we used the following keywords: "lung fibrosis", "fibrosis mediators", "fibrosis predictors", "COVID-19", "SARS-CoV-2 infection", and "long COVID-19". In this narrative review, we aimed to discuss the current understanding of the mechanisms of initiation and progression of post-COVID-19 lung fibrosis (PC-19-LF) and the risk factors for its occurrence. The pathogenesis of pulmonary fibrosis involves various mediators such as TGF-β, legumain, osteopontin, IL-4, IL-6, IL-13, IL-17, TNF-α, Gal-1, Gal-3, PDGF, and FGFR-1. The key cellular effectors involved in COVID-19 lung fibrosis are macrophages, epithelial alveolar cells, neutrophils, and fibroblasts. The main fibrosis pathways in SARS-CoV-2 infection include hypoxemia-induced fibrosis, macrophage-induced fibrosis, and viral-fibroblast interaction-induced fibrosis.

Vaccination with parasite-specific TcTASV proteins combined with recombinant baculovirus as a delivery platform protects against acute and chronic Trypanosoma cruzi infection.

Chagas' is a neglected disease caused by the eukaryotic kinetoplastid parasite, Trypanosoma cruzi. Currently, approximately 8 million people are infected worldwide, most of whom are in the chronic phase of the disease, which involves cardiac, digestive, or neurologic manifestations. There is an urgent need for a vaccine because treatments are only effective in the initial phase of infection, which is generally underdiagnosed. The selection and combination of antigens, adjuvants, and delivery platforms for vaccine formulations should be designed to trigger mixed humoral and cellular immune responses, considering that T. cruzi has a complex life cycle with both intracellular and bloodstream circulating parasite stages in vertebrate hosts. Here, we report the effectiveness of vaccination with a T. cruzi-specific protein family (TcTASV), employing both recombinant proteins with aluminum hydroxide and a recombinant baculovirus displaying a TcTASV antigen at the capsid. Vaccination stimulated immunological responses by producing lytic antibodies and antigen-specific CD4+ and CD8+ IFNɣ secreting lymphocytes. More than 90% of vaccinated animals survived after lethal challenges with T. cruzi, whereas all control mice died before 30 days post-infection. Vaccination also induced a strong decrease in chronic tissue parasitism and generated immunological memory that allowed vaccinated and infected animals to control both the reactivation of the infection after immunosuppression and a second challenge with T. cruzi. Interestingly, inoculation with wild-type baculovirus partially protected the mice against T. cruzi. In brief, we demonstrated for the first time that the combination of the baculovirus platform and the TcTASV family provides effective protection against Trypanosoma cruzi, which is a promising vaccine for Chagas disease.

γδ T cell-mediated activation of cDC1 orchestrates CD4+ Th1 cell priming in malaria.

γδ T cells facilitate the CD4+ T helper 1 (Th1) cell response against Plasmodium infection by activating conventional dendritic cells (cDCs), although the underlying mechanism remains elusive. Our study revealed that γδ T cells promote the complete maturation and production of interleukin-12 and CXCR3-ligands specifically in type 1 cDCs (cDC1), with minimal impact on cDC2 and monocyte derived DCs (Mo-DCs). During the initial infection phase, γδ T cell activation and temporal accumulation in the splenic white pulp, alongside cDC1, occur via CCR7-signaling. Furthermore, cDC1/γδ T cell interactions in the white pulp are amplified through CXCR3 signaling in γδ T cells, optimizing Th1 cell priming by cDC1. We also demonstrated how transitional Th1 cells arise in the white pulp before establishing their presence in the red pulp as fully differentiated Th1 cells. Additionally, we elucidate the reciprocal activation between γδ T cells and cDC1s. These findings suggest that Th1 cell priming is orchestrated by this reciprocal activation in the splenic white pulp during the early phase of blood-stage Plasmodium infection.

Characterization and predictive risk scoring of long COVID in a south indian cohort after breakthrough COVID infection; a prospective single centre study

BackgroundWith the World Health Organization (WHO) declaring an end to the COVID-19 pandemic, the focus has shifted to understanding and managing long-term post-infectious complications. “Long COVID,“ characterized by persistent or new onset symptoms extending beyond the initial phase of infection, is one such complication. This study aims to describe the incidence, clinical features and risk profile of long COVID among individuals in a South Indian cohort who experienced post-ChAdOx1 n-Cov-2 vaccine breakthrough infections.MethodsA single-centre hospital-based prospective observational study was conducted from October to December 2021. The study population comprised adult patients (> 18 years) with a confirmed COVID-19 diagnosis who had received at least a single dose of vaccination. Data was collected using a specially tailored questionnaire at week 2, week 6, and week 12 post-negative COVID-19 test. A propensity score based predictive scoring system was developed to assess the risk of long COVID.ResultsAmong the 414 patients followed up in the study, 164 (39.6%) reported long COVID symptoms persisting beyond 6 week’s post-infection. The presence of long COVID was significantly higher among patients above 65 years of age, and those with comorbidities such as Type II Diabetes Mellitus, hypertension, dyslipidemia, coronary artery disease, asthma, and cancer. Using backwards selection, a reduced model was developed, identifying age (OR 1.053, 95% CI 0.097–1.07, p < 0.001), hypertension (OR 2.59, 95% CI 1.46–4.59, p = 0.001), and bronchial asthma (OR 3.7176, 95% CI 1.24–11.12, p = 0.018) as significant predictors of long COVID incidence. A significant positive correlation was observed between the symptomatic burden and the number of individual comorbidities.ConclusionsThe significant presence of long COVID at 12 weeks among non-hospitalised patients underscores the importance of post-recovery follow-up to assess for the presence of long COVID. The predictive risk score proposed in this study may help identify individuals at risk of developing long COVID. Further research is needed to understand the impact of long COVID on patients’ quality of life and the potential role of tailored rehabilitation programs in improving patient outcomes.

Unveiling the Mysteries of Long COVID Syndrome: Exploring the Distinct Tissue and Organ Pathologies Linked to Prolonged COVID-19 Symptoms.

The ongoing battle against the coronavirus disease 2019 (COVID-19) pandemic has encountered a complex aspect with the emergence of long COVID syndrome. There has been a growing prevalence of COVID-19-affected individuals experiencing persistent and diverse symptoms that extend beyond the initial infection phase. The phenomenon known as long COVID syndrome raises significant questions about the underlying mechanisms driving these enduring symptoms. This comprehensive analysis explores the complex domain of long COVID syndrome with a view to shed light on the specific tissue and organ pathologies contributing to its intricate nature. This review aims to analyze the various clinical manifestations of this condition across different bodily systems and explore potential mechanisms such as viral persistence, immune dysregulation, autoimmunity, and molecular mimicry. The goal is to gain a better understanding of the intricate network of pathologies contributing to long COVID syndrome. Understanding these distinct pathological indicators provides valuable insights into comprehending the complexities of long COVID and presents opportunities for developing more accurate diagnostic and therapeutic strategies, thereby improving the quality of patient care by effectively addressing the ever-changing medical challenge in a more focused manner.

Polineuropatía asociada a infección por VIH. Revisión del tema y presentación de un caso

La infección por el virus de inmunodeficiencia humana (VIH) constituye un problema de salud pública. La afectación neurológica en los pacientes infectados por el VIH es frecuente, involucrando tanto al sistema nervioso central como al periférico, y en algunos casos puede ser la primera manifestación de la infección. Entre las afecciones neurológicas, las neuropatías periféricas pueden observarse en el 100% de las autopsias. Las mismas pueden adoptar diferentes formas, que por lo general dependen de la fase de la enfermedad en la que se encuentre el paciente. Las neuropatías autoinmunes como el síndrome de Guillain-Barré y la polineuropatía desmielinizante inflamatoria crónica (CIDP) aparecen en los estadios iniciales de la infección, cuando el conteo de CD4 está ligeramente disminuido. La CIDP tiene criterios clínicos y electrofisiológicos bien definidos que la diferencian de otras formas de neuropatías periféricas, responde bien al tratamiento inmunomodulador, pero su diagnóstico puede ser difícil de realizar debido a su forma insidiosa de comienzo. Se realiza una breve revisión de las neuropatías periféricas que pueden asociarse a la infección por VIH y se presenta un caso de asociación de esta infección con CIDP.

Clinical laboratory diagnostics of antibodies to SARS-CoV-2: from a QR code to the reality

Background: The immune response to SARS-CoV-2 includes the production of specific immunoglobulins to protein antigens of SARS-CoV-2. Depending on the type and level of immunoglobulins, it is possible to assess the stage of the disease and evaluate the effectiveness of vaccination. The main approach to the determination of immunoglobulins to SARS-CoV-2 in human biological fluids is enzyme-linked sorbent immunoassay. Its data, in particular, are used to issue an electronic COVID-19 certificate with a QR code. However, the qualitative and quantitative composition of immunoglobulins for a QR code is not officially regulated. Aim: measuring the immunoglobulins level in the human blood serum with different types of immunity to the new coronavirus infection (COVID-19) to select the most informative indicators of protective immunity. Methods: The study included 76 blood serum samples from male and female volunteers (age, 18 to 50 y.o.) in compliance with the ethical standards. The detection of IgA, IgM, IgG (total to different regions of SARS-CoV-2, S-protein IgG and RBD-fragment IgG), IgG avidity, and the level of the SARS-CoV-2 N-antigen was performed by enzyme-linked immunosorbent assay (ELISA) using commercially available reagent kits. Results: The indicators of the level of antibodies (both "protective" IgG and IgA of the initial phase of infection) are most pronounced in persons who have been vaccinated and have had COVID-19, and least pronounced in unvaccinated people. For recovered unvaccinated individuals, the level of total protective antibodies and IgG to the S-protein, including the RBD fragment, is the lowest; the avidity of IgG is lower than that in the other groups, too. The IgG avidity in vaccinated patients is higher than that in recovered ones. It should be noted that there were no differences in the level of both total IgG to SARS-CoV-2, to the S-protein and to the RBD-fragment of the S-protein for recovered and vaccinated individuals. Conclusion: The analysis of COVID-19 immunoglobulins indicates a different profile of the humoral immune response following vaccination and previous infection with COVID-19. To quickly assess the immune response to previous and current COVID-19 infection, as well as to detect the post-vaccination immunity, it is advisable to use the total level of IgG to SARS-CoV-2. For deeper assessment of protective immunity and production of protective antibodies, it is better to evaluate the quantitative content of IgG to the S protein and its RBD fragment. The equal level of IgA in the experimental groups indicates an ongoing interaction with SARS CoV-2 in the population. Thus, the electronic COVID-19 certificate is of little use when it is formed by only one of the indicators without taking into account the rest.

Efficacy and Safety of Inhaled Ethanol in Early-Stage SARS-CoV-2 Infection in Older Adults: A Phase II Randomized Clinical Trial

Inhaled ethanol in the early stages of SARS-CoV-2 infection may reduce the viral load, decreasing progression and improving prognosis. The ALCOVID-19 trial was designed to study the efficacy and safety of inhaled ethanol in older adults at initial phases of infection. Randomized, triple-blind, placebo-controlled phase II clinical trial. Experimental group (n = 38) inhaled 65° ethanol through an oxygen flow, while in the control group (n = 37), water for injection was used. General endpoint was to evaluate disease progression according to the modified World Health Organization (WHO) Clinical Progression Scale. Specific effectiveness endpoints were body temperature, oxygen saturation, viral load assessed by cycle threshold (Ct) on real-time polymerase chain reaction (RT-PCR), analytical biomarkers and use of antibiotics or corticosteroids. Specific safety outcomes were the absence of ethanol in plasma, electrographic, analytical, or respiratory alterations. In the intention-to-treat population, no differences were found regarding disease progression. Mean Ct values increased over time in both groups, being numerically higher in the ethanol group, reaching a value above 33 only in the ethanol group on day 14, a value above which patients are considered non-infective. No differences were found in the other specific effectiveness endpoints. Inhaled ethanol was proven to be safe as no plasma ethanol was detected, and there were no electrocardiographic, analytical, or respiratory alterations. The efficacy of inhaled ethanol in terms of the progression of SARS-CoV-2 infection was not demonstrated in the present trial. However, it is positioned as a safe treatment for elderly patients with early-stage COVID-19.

Long COVID-19 syndrome: association of cardiopulmonary impairment with a persistent platelet activation

Abstract Background A considerable proportion of patients do not fully recover from COVID-19 infection and report symptoms that persist beyond the initial phase of infection: this condition is defined long-COVID-19 syndrome (LCS). LCS can involve lungs as well as several extrapulmonary organs, including the cardiovascular system. The risk and 1-year burden of cardiovascular diseases (CVD) is increased in COVID-19 survivors, even in subjects at low risk of CVD. Recently, we documented that acute COVID-19 infection induces altered platelet activation state characterized by a prothrombotic phenotype and by the formation of platelet-leukocyte aggregates (PLA), that may be involved in the pulmonary microthrombi found in autoptic specimens. No data are yet available on the contribution of platelet activation to residual pulmonary impairment and procoagulant potential in LCS patients. Purpose To study platelet activation status, microvesicle (MV) profile, platelet thrombin generation capacity (pTGC) in LCS patients enrolled at 6 months after resolution of the acute phase (6mo-FU), compared to acute COVID-19 infection patients. Methods 6mo-FU COVID-19 patients (n=24) with established LCS were enrolled at Centro Cardiologico Monzino. Residual pulmonary impairment was assessed by Cardiopulmonary Exercise Testing (CPET) and 64-rows-CT scan evaluation. Platelet activation (P-selectin, Tissue Factor [TF] and PLA) and MV profile were assessed by flow cytometry; pTGC by calibrated automated thrombogram. 46 patients enrolled during acute COVID-19 infection and 46 healthy subjects (HS) were used for comparison. Results Dispnea in LCS patients was confirmed by CPET showing compromised alveolus-capillary membrane diffusion and residual pulmonary impairment. TF+-platelet and -MV levels were 3-fold (1.5% [1.2–2.9] vs 2.4% [1.6–5.7]) and 2-fold (217/μl [137–275] vs 435/μl [275–633]) lower at 6mo-FU compared to acute phase, being comparable to HS. pTGC behaved similarly. At 6mo-FU, the MV profile, in terms of total number and cell origin, returned to physiological levels. Conversely, although lower than that measured in acute phase, a 2.5-fold higher platelet P-selectin expression (6.9% [3–13.5] vs 11.7% [5.2–18.9]) and PLA formation (35.5% [27.4–46.8] vs 67.7% [45.7–85.3]) was observed at 6mo-FU compared to HS. Interestingly, a significant correlation between PLA formation and residual pulmonary impairment was observed (r=−0.423; p=0.02). Conclusion These data strengthen the hypothesis that the presence of PLA in the bloodstream, and thus also in the pulmonary microcirculation, may contribute to support pulmonary dysfunction still observed in LCS patients. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health (Ricerca Corrente 2020 MPP COVID4)