Epidemiological Study in Antiviral Innate Immunity.

This chapter summarizes the epidemiological study design of natural immune epidemiology studies based on recent COVID-19-related research. The epidemiological studies on antiviral innate immunity have mainly included randomized controlled trials (RCTs) and observational studies. Importantly, this chapter will discuss how to use these methodologies to answer an epidemiological question of natural immunity in the viral infection process based on previous studies. An observational case- or cohort-based study of antiviral innate immunity may support this theoretical hypothesis but is not appropriate for clinical practice or treatment. RCTs are the gold standard for epidemiological studies and occupy a greater role in the hierarchy of evidence.

Pulmonary delivery of silver nanoparticles prevents influenza infection by recruiting and activating lymphoid cells.

Silver nanoparticles (AgNPs) are a potential antiviral agent due to their ability to disrupt the viral particle or alter the virus metabolism inside the host cell. In vitro, AgNPs exhibit antiviral activity against the most common human respiratory viruses. However, their capacity to modulate immune responses during respiratory viral infections has yet to be explored. This study demonstrates that administering AgNPs directly into the lungs prior to infection can reduce viral loads and therefore virus-induced cytokines in mice infected with influenza virus or murine pneumonia virus. The prophylactic effect was diminished in mice with depleted lymphoid cells. We showed that AgNPs-treatment resulted in the recruitment and activation of lymphocytes in the lungs, particularly natural killer (NK) cells. Mechanistically, AgNPs enhanced the ability of alveolar macrophages to promote both NK cell migration and IFN-γ production. By contrast, following infection, in mice treated with AgNPs, NK cells exhibited decreased activation, indicating that these nanoparticles can regulate the potentially deleterious activation of these cells. Overall, the data suggest that AgNPs may possess prophylactic antiviral properties by recruiting and controlling the activation of lymphoid cells through interaction with alveolar macrophages.

Paxlovid for the treatment of COVID-19: a systematic review and meta-analysis.

INTRODUCTION: Paxlovid (nirmatrelvir/ritonavir) is a new oral antiviral drug that is used for coronavirus disease 2019 (COVID-19) and is administered to patients with mild to moderate disease for five consecutive days. This meta-analysis aimed to evaluate the efficacy of Paxlovid in COVID-19 patients. METHODOLOGY: PubMed, Embase, Cochrane Library, and Web of Science databases were searched to identify relevant publications up to 9 March 2023. Three randomized controlled trial (RCT) studies, one prospective cohort study, and 25 retrospective cohort studies were identified for the meta-analysis. RESULTS: There was a significant difference between the Paxlovid and control groups in terms of hospitalization (RR = 0.53; 95% CI: 0.24-0.69, p < 0.001), all-cause mortality (RR = 0.36; 95% CI: 0.27-0.50, p < 0.001), hospitalization or death (RR = 0.50; 95% CI: 0.37-0.67, p < 0.001), intensive care unit admission (RR = 0.45; 95% CI: 0.27-0.73, p = 0.001), and emergency department visits (RR = 0.67; 95% CI: 0.54-0.83, p < 0.001). However, no significant difference was found between the two groups in terms of COVID-19 rebound (OR = 1.18; 95% CI: 0.82-1.68, p = 0.37). In addition, the Paxlovid group had a significantly shorter hospital length of stay (weighted mean difference WMD = -1.11; 95% CI, -1.81, -0.41; I2 > 50%, p < 0.05), and polymerase chain reaction negative conversion time (WMD = -2.75; 95% CI, -3.60, -1.89, I2 > 50%, p < 0.05) than that of the control group. CONCLUSIONS: Paxlovid can be considered an effective therapeutic agent for treating patients with COVID-19.

Real-world study on the efficacy and safety of different treatment regimens in treatment-naïve CHB patients with high viral load.

Evaluate the real-world effectiveness and safety of different treatment regimens for treatment-naïve high viral load chronic hepatitis B (CHB) patients. Between January 2021 and August 2022, CHB patients with HBV DNA ≥ 107 IU/mL were collected from four medical centers in Shenzhen. Patients treated with mono or combine antiviral therapy. The primary endpoint was the cumulative incidence of virological response at 48 weeks, and other endpoints included changes in HBsAg, HBeAg, ALT, and eGFR at 48 weeks. We used propensity score-based inverse probability of treatment weighting (IPTW) to balance the bias. Weighted logistics regression was used to estimate the factors affecting virological response. A total of 391 patients were included in the study, with 296 patients undergoing statistical analysis after IPTW. The patients were distributed into four groups: ETV (n = 62), TDF (n = 89), TAF (n = 36), TDF + LdT/ETV (n = 109). The 48-week cumulative incidence of virological response was significantly lower in ETV group (52.3%) compared to TDF (71.7%), TAF (74.2%), and TDF + LdT/ETV groups (77.9%) (P < 0.05). There were no significant differences in HBsAg loss among the four groups, but the HBeAg seroconversion rate was significantly higher in the TAF group. The ALT normalization rate was significantly higher in the TAF group (72.2%) compared to the others at 48 weeks (P < 0.05). In treatment-naïve CHB patients with high viral load, combination therapy was not superior to TDF or TAF monotherapy in virological response. Patients treated with TDF or TAF showed superior virological response compared to those treated with ETV. The TAF group demonstrated superiority in terms of ALT normalization and HBeAg seroconversion.

Safety of remdesivir in the treatment of acute SARS-CoV-2 infection in pediatric patients.

BACKGROUND: Transaminase and creatinine elevations have been well described in adults treated with remdesivir for COVID-19. It is hypothesized that a similar safety profile exists in children with COVID-19 treated with remdesivir, but available data are limited, especially in children < 12 months. The primary aim of this study was to determine the prevalence and timing of elevations in transaminases and creatinine in children with COVID-19 who were treated with remdesivir. METHODS: This was a retrospective, observational cohort study including all pediatric patients admitted to a single, freestanding children's hospital who were positive for COVID-19 and received at least 1 dose of remdesivir between 1/1/2020 and 5/31/2022. Available baseline and peak transaminase and creatinine concentrations were evaluated. Multivariable logistic regression analysis was performed to identify risk factors for transaminase elevation. RESULTS: A total of 180 patients met inclusion criteria. Creatinine elevation of any grade was noted in 16% and remained elevated only in those with underlying chronic kidney disease. Transaminase elevation of any grade was noted in 58% of patients and remained elevated in only 1%. Older age and critical respiratory disease were associated with higher risk of significant transaminase elevation, whereas non-Hispanic ethnicity was strongly associated with protection against significant transaminase elevation. CONCLUSIONS: In our cohort of hospitalized children with COVID-19 who were treated with remdesivir, most patients experienced only mild transaminitis and normal creatinine concentrations. A limited number of patients experienced laboratory abnormalities which were transient, suggesting a favorable safety profile for remdesivir use in pediatrics.

Comparison of Cytomegalovirus Reactivation in Children After Allogeneic Hematopoietic Cell Transplantation in 2 Transplant Eras.

BACKGROUND: Reactivation of cytomegalovirus (CMV) is typically considered harmless as long as the immune system remains unaffected by medications or other factors. CMV reactivation may occur as a result of acute graft-versus-host disease of Grades II to IV. One possible factor contributing to this risk is the rise in the number of donors who lack genetic similarities or relationships. We hypothesized that the anti-CMV IgG level before transplantation could potentially serve as an indicator of the likelihood of CMV reactivation following hematopoietic cell transplantation. METHODS: We examined a cohort of young individuals who underwent allogeneic HCT between 1998 and 2022 to evaluate the occurrence of CMV reactivation. The patients were divided into 2 time periods: 1998 to 2016 (comparison group) and 2017 to 2022 (intervention group). RESULTS: Between 1998 and 2016, 292 patients underwent hematopoietic HCT. Recipients from 2017 to 2022 experienced a slightly higher risk of CMV reactivation than those from 1998 to 2016. The comparison of prophylactic and preemptive medication showed no significant difference between the periods (P = .32). Patients treated from 1998 to 2016 experienced a 23% decrease in the risk of symptomatic CMV reactivation and related illnesses compared to those treated from 2017 to 2022 (P = .08 and .15, respectively). CONCLUSIONS: Our study showed that the intervention group had more symptomatic CMV reactivations. Various factors may contribute to this, including CD19-directed immunotherapy and the CMV status of the recipient before transplantation.

Role of tenofovir dipivoxil in gut microbiota recovery from HBV-infection induced dysbiosis.

BACKGROUND: Studies have found dysbiosis of the gut microbiota in individuals infected with the hepatitis B virus (HBV). Tenofovir dipivoxil (TDF) is one of the preferred oral antiviral drugs used for the treatment of chronic hepatitis B (CHB), but the extent to which TDF is able to affect the gut microbiota and inflammatory factors of a patient remains largely unexplored. In this study, we collected stool samples from HBV patients prior to medication and from CHB patients treated with TDF. RESULTS: The gut microbiota and inflammatory factors were assessed in 42 healthy subjects (HC group), 109 HBV-infected subjects, including 48 CHB patients who were not medicated with nucleoside analogue drugs (No-NAs group), and 61 CHB patients who were medicated with TDF (TDF group). 16 S rRNA sequencing revealed that TDF treatment caused significant changes in the gut microbiota of HBV-infected individuals; however, the gut microbiota of HBV-infected individuals did not fully recover to a pre-dysbiosis state. The relative abundance of Bacteroidota gradually decreased from the HC group to the No-NAs and TDF groups. The relative abundance of Fusobacteriota was significantly higher in the No-NAs group than in the HC group. At the genus level, Dialister, Eubacterium_hallii_group, Halomonas, Collinsella, Sphingomonas, Xanthomonadaceae_unclassified, and Rhizobiaceae_unclassified were overrepresented; while the abundance of Bacteroides and Fusobacterium decreased significantly in the No-NAs and TDF groups. CONCLUSIONS: This study showed that TDF treatment significantly improved the regulation of the gut microbiota and aided in dysbiosis recovery. We did not observe significant improvement in serum inflammatory factor concentrations, which may be related to the relatively short duration of TDF administration in this study.

Possible drug-drug interactions among elderly patients receiving antiviral therapy for chronic hepatitis B.

AIM: To identify possible drug-drug interactions in patients taking medications for other comorbidities while on antiviral therapy for chronic hepatitis B. METHODS: The study enrolled patients with chronic hepatitis B aged ≥60 years who were treated with antiviral therapy in five hospitals in Turkey between January 1 and March 1, 2023. The Lexicomp® Drug Interactions program was used to identify possible drug-drug interactions. RESULTS: The study included 213 patients (119 [55.9%] men). The mean age was 68.5 years. A potential drug-drug interaction was identified in 112 patients (52.6%). The most common type of interaction was type C ("follow the treatment") (71.54%). The number of potential drug-drug interactions increased with an increase in the number of drugs used by the patients. A robust and affirmative correlation was observed between the number of medications used and the number of possible drug-drug interactions (r=0.791, P<0.001). Adverse interactions (interactions of types C and D, 3.7% of cases) were limited to patients receiving tenofovir disoproxil fumarate. CONCLUSION: Nonsteroidal anti-inflammatory medications should be used cautiously in elderly patients with chronic hepatitis B treated with tenofovir disoproxil fumarate due to the increased risk of renal toxicity.

Development and Prospects of Furin Inhibitors for Therapeutic Applications.

Furin, a serine protease enzyme located in the Golgi apparatus of animal cells, plays a crucial role in cleaving precursor proteins into their mature, active forms. It is ubiquitously expressed across various tissues, including the brain, lungs, gastrointestinal tract, liver, pancreas, and reproductive organs. Since its discovery in 1990, furin has been recognized as a significant therapeutic target, leading to the active development of furin inhibitors for potential use in antiviral, antibacterial, anticancer, and other therapeutic applications. This review provides a comprehensive overview of the progress in the development and characterization of furin inhibitors, encompassing peptides, linear and macrocyclic peptidomimetics, and non-peptide compounds, highlighting their potential in the treatment of both infectious and non-infectious diseases.

Viral Factors in Modulation of Host Immune Response: A Route to Novel Antiviral Agents and New Therapeutic Approaches.

Viruses utilize host cells at all stages of their life cycle, from the transcription of genes and translation of viral proteins to the release of viral copies. The human immune system counteracts viruses through a variety of complex mechanisms, including both innate and adaptive components. Viruses have an ability to evade different components of the immune system and affect them, leading to disruption. This review covers contemporary knowledge about the virus-induced complex interplay of molecular interactions, including regulation of transcription and translation in host cells resulting in the modulation of immune system functions. Thorough investigation of molecular mechanisms and signaling pathways that are involved in modulating of host immune response to viral infections can help to develop novel approaches for antiviral therapy. In this review, we consider new therapeutic approaches for antiviral treatment. Modern therapeutic strategies for the treatment and cure of human immunodeficiency virus (HIV) are considered in detail because HIV is a unique example of a virus that leads to host T lymphocyte deregulation and significant modulation of the host immune response. Furthermore, peculiarities of some promising novel agents for the treatment of various viral infections are described.

Comparative efficacy and safety of tenofovir amibufenamide vs tenofovir alafenamide in the initial 48-week treatment of high viral load chronic hepatitis B: A single-centre retrospective study.

BACKGROUND/AIM: Tenofovir amibufenamide (TMF) employs innovative ProTide technology and a methylation strategy to enhance the lipid solubility and plasma stability of the amide bond, providing advantages over tenofovir alafenamide (TAF). Despite promising Phase III clinical trial results demonstrating its antiviral efficacy, real-world data on TMF remains scarce. This study evaluates the antiviral efficacy and safety of TMF compared to TAF as the initial treatment in patients with high viral loads of chronic hepatitis B (CHB). METHODS: We retrospectively collected clinical data from March 1 2022 to June 30 2022 for highly viremic CHB patients who received either TMF (n = 58) or TAF (n = 32) as their initial monotherapy at Beijing YouAn Hospital. To understand the efficacy and safety of TMF over 48 weeks, we compared the virological response rates and HBeAg/HBsAg serological clearance rates between TMF and TAF groups. Also, the changes in serum creatinine, eGFR and serum lipid levels were assessed. RESULTS: Baseline median HBV DNA levels were 7.85 (6.89, 8.36) IgIU/ml for TMF and 7.44 (6.89, 8.03) IgIU/ml for TAF. Median ALT levels were 102.0 (56.0, 210.0) U/L for TMF and 195.0 (73.5, 371.0) U/L for TAF, with HBeAg positivity rates of 70.7% and 75.0%, respectively. At 48 weeks, virological response rates (HBV DNA <10 IU/ml) were 43.5% (20/46) for TMF and 42.9% (12/28) for TAF (p = 1.000). ALT normalization rates were 87.9% for TMF and 90.6% for TAF (p = .969), and HBeAg serological clearance rates were 21.1% and 18.2%, respectively (p = 1.000). No patients achieved HBsAg clearance. Compared with the baseline, LDL-C levels increased, while eGFR decreased, with no significant differences in serum creatinine, triglycerides and total cholesterol levels noted at week 48 for both TMF and TAF groups. CONCLUSION: TMF demonstrates comparable antiviral efficacy to TAF when used as initial therapy in highly viremic CHB patients, with similar impacts on renal function and lipid profiles.

Human Cathelicidin, LL-37 a potential antiviral therapeutic for Rift Valley Fever Virus in Egypt.

Rift Valley Fever Virus (RVFV) is an arbovirus that circulates among animals and can be transmitted to humans. Mosquitoes are the primary vectors that allow RVFV to spread vertically and horizontally. Egypt was exposed to frequent outbreaks with devastating economic consequences. RVFV has a high incidence of worldwide dissemination and no specific vaccine or therapy. Linear Human Cathelicidin (LL-37), is a natural antimicrobial peptide with antiviral activity against numerous viruses. In addition to immunomodulatory effects, LL-37 directly influences viral encapsulation. This study aimed to evaluate the antiviral activity of LL-37 against RVFV in vitro. The post-entry and pre-incubation of LL-37 within Vero cells were assessed in the absence and presence of RVFV. LL-37 activity was assessed using a TCID50 endpoint test, qRT-PCR, and a western blot. When genomic RVFV was quantified, it resulted in a 48% direct inactivation of the viral envelope and a 36% reduction when the virus was pre-incubated with LL-37 before infection. LL-37 decreased viral infection by 75% and protected Vero cells against RVFV infection by 47% at a 1.25 µg/ml dosage. These findings imply that LL-37 exerts antiviral efficacy against RVFV by restricting virus entrance through direct disruption of the virus envelope and indirectly by triggering an immunological response. The effect of LL-37 is time-dependent. As a result, LL-37 may provide rapid and affordable therapies for RVFV infection in Egypt, both during outbreaks and as a preventive strategy.

How many organic small molecules might be used to treat COVID-19? From natural products to synthetic agents.

A large scale of pandemic coronavirus disease (COVID-19) in the past five years motivates a great deal of endeavors donating to the exploration on therapeutic drugs against COVID-19 as well as other diseases caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein is an overview on the organic small molecules that are potentially employed to treat COVID-19 and other SARS-CoV-2-related diseases. These organic small molecules are accessed from both natural resources and synthetic strategies. Notably, typical natural products presented herein consist of polyphenols, lignans, alkaloids, terpenoids, and peptides, which exert an advantage for the further discovery of novel anti-COVID-19 drugs from plant herbs. On the other hand, synthetic prodrugs are composed of a series of inhibitors towards RNA-dependent RNA polymerase (RdRp), main protease (Mpro), 3-chymotrypsin-like cysteine protease (3CLpro), spike protein, papain-like protease (PLpro) of the SARS-CoV-2 as well as the angiotensin-converting enzyme 2 (ACE2) in the host cells. Synthetic strategies are worth taken into consideration because they are beneficial for designing novel anti-COVID-19 drugs in the coming investigations. Although examples collected herein are just a drop in the bucket, developments of organic small molecules against coronavirus infections are believed to pave a promising way for the discovery of multi-targeted therapeutic drugs against not only COVID-19 but also other virus-mediated diseases.

Molecular and phenotypic characteristics of respiratory syncytial virus isolates recovered from medically vulnerable children: An exploratory analysis of a phase 2/3 randomized, double-blind, palivizumab-controlled trial of nirsevimab (MEDLEY).

BACKGROUND: Nirsevimab is an extended half-life monoclonal antibody (mAb) licensed for the prevention of respiratory syncytial virus (RSV)-associated lower respiratory tract disease in neonates, infants and medically vulnerable children. We characterized RSV isolates recovered from participants enrolled in MEDLEY: a randomized, palivizumab-controlled phase 2/3 trial of nirsevimab in infants born preterm and/or with congenital heart disease or chronic lung disease of prematurity. METHODS: Participants were assessed in two RSV seasons (Season 1 and 2). Season 1 participants were randomized (2:1) to receive a single dose of nirsevimab (50 mg if weight <5 kg or 100 mg if weight ≥5 kg in Season 1; 200 mg in Season 2) followed by four monthly doses of placebo, or five once-monthly doses of palivizumab (15 mg/kg weight per dose). Season 2 participants continued nirsevimab and placebo (nirsevimab/nirsevimab) or were re-randomized (1:1) to switch to nirsevimab (palivizumab/nirsevimab) or continue palivizumab (palivizumab/palivizumab). Cases of RSV infection were identified by central testing of nasal swabs from participants seeking medical attention for respiratory illnesses. Nirsevimab and palivizumab binding site substitutions were assessed via microneutralization assay. RESULTS: Twenty-five cases of confirmed RSV infection were observed during the trial and sequenced: 12 in nirsevimab recipients and 10 in palivizumab recipients during Season 1, and 1 case in each Season 2 group. Molecular sequencing of RSV A (n = 14) isolates detected no nirsevimab binding site substitutions, and 3 palivizumab neutralization-resistant substitutions (Lys272Met, Lys272Thr, Ser275Leu). The nirsevimab binding site Ile206Met:Gln209Arg and Ile206Met:Gln209Arg:Ser211Asn substitutions were the only anti-RSV mAb binding site substitutions detected among RSV B isolates (n = 11). Nirsevimab neutralized all nirsevimab and palivizumab binding site substitutions in RSV A and B isolates recovered from MEDLEY participants. CONCLUSION: No binding site substitution detected during MEDLEY affected RSV susceptibility to nirsevimab neutralization.

Herpes zoster as the initial manifestation of varicella-zoster virus infection in a healthy toddler.

Herpes zoster (HZ), commonly known as shingles, is a painful blistering rash in dermatomal distribution, caused by the reactivation of varicella-zoster virus (VZV) that was acquired during a primary varicella infection. While commonly afflicting adults, cases of HZ in paediatric patients are infrequently reported. Such cases are predominantly reported in children who have had prior exposure to VZV, either during pregnancy, early childhood or have been vaccinated with live attenuated VZV. This report presents the first known case to our knowledge of HZ as the initial manifestation of a VZV infection in an immunocompetent toddler in the UK. The report details the chronology of the infection event and discusses the clinical context behind HZ presentations in paediatrics globally. It provides a compelling illustration of the uncommon presentation of VZV infection in an immunocompetent child devoid of antecedent virus exposure, thus meriting acknowledgement and potentially further investigation as to the cause.

Potential of 6'­hydroxy justicidin B from Justicia procumbens as a therapeutic agent against coronavirus disease 2019.

BACKGROUND: Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, remarkable advances have been made in vaccine development to reduce mortality. However, therapeutic interventions for COVID-19 are comparatively limited despite these intensive efforts. Furthermore, the rapid mutation capability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a characteristic of its RNA structure, has led to the emergence of multiple variants, necessitating a shift from a predominantly vaccine-centric approach to one that encompasses therapeutic strategies. 6'-Hydroxy justicidin B (6'-HJB), an arylnaphthalene lignan isolated from Justicia procumbens, a traditional Chinese medicine, is known for its antiviral properties. HYPOTHESIS/PURPOSE: The aim of the present study was to assess the effectiveness and safety of 6'-HJB against SARS-CoV-2 in order to determine its potential as a therapeutic agent against COVID-19. METHODS: The efficacy of 6'-HJB was evaluated both in vitro using Vero and Calu-3 cell lines and in vivo using ferrets. The safety assessment included toxicokinetics, safety pharmacology, and Good Laboratory Practice (GLP)-compliant toxicity evaluations following single- and repeated-dose toxicity studies in dogs. RESULTS: The anti-SARS-CoV-2 efficacy of 6'-HJB was evaluated through dose-response curve (DRC) analysis using immunofluorescence; 6'-HJB demonstrated superior inhibition of SARS-CoV-2 growth and lower cytotoxicity than remdesivir. In SARS-CoV-2-infected ferret, 6'-HJB showed efficacy comparable to that of the positive control, Truvada. Further GLP toxicity studies corroborated the safety profile of 6'-HJB. Single-dose and 4-week repeated oral toxicity studies in Beagle dogs demonstrated minimal harmful effects at the highest dosages. The lethal dose of 6'-HJB exceeded 2,000 mg kg-1 in Beagle dogs. Toxicokinetic and GLP safety pharmacology studies demonstrated no adverse effects of 6'-HJB on metabolic processes, respiratory or central nervous systems, or cardiac functions. CONCLUSION: This research highlights both the antiviral efficacy and safety profile of 6'-HJB, underscoring its potential as a novel COVID-19 treatment option. The potential of 6'-HJB was demonstrated using modern scientific methodologies and standards.

Antiviral Effectiveness, Clinical Outcomes, and Artificial Intelligence Imaging Analysis for Hospitalized COVID-19 Patients Receiving Antivirals.

INTRODUCTION: There is still a lack of clinical evidence comprehensively evaluating the effectiveness of antiviral treatments for COVID-19 hospitalized patients. METHODS: A retrospective cohort study was conducted at Beijing You'An Hospital, focusing on patients treated with nirmatrelvir/ritonavir or azvudine. The study employed a tripartite analysis-viral dynamics, survival curve analysis, and AI-based radiological analysis of pulmonary CT images-aiming to assess the severity of pneumonia. RESULTS: Of 370 patients treated with either nirmatrelvir/ritonavir or azvudine as monotherapy, those in the nirmatrelvir/ritonavir group experienced faster viral clearance than those treated with azvudine (5.4 days vs. 8.4 days, p < 0.001). No significant differences were observed in the survival curves between the two drug groups. AI-based radiological analysis revealed that patients in the nirmatrelvir group had more severe pneumonia conditions (infection ratio is 11.1 vs. 5.35, p = 0.007). Patients with an infection ratio higher than 9.2 had nearly three times the mortality rate compared to those with an infection ratio lower than 9.2. CONCLUSIONS: Our study suggests that in real-world studies regarding hospitalized patients with COVID-19 pneumonia, the antiviral effect of nirmatrelvir/ritonavir is significantly superior to azvudine, but the choice of antiviral agents is not necessarily linked to clinical outcomes; the severity of pneumonia at admission is the most important factor to determine prognosis. Additionally, our findings indicate that pulmonary AI imaging analysis can be a powerful tool for predicting patient prognosis and guiding clinical decision-making.

Changes of CD8+CD28- Tregs and Gamma-Delta-T-cells in a Neonate with Intrauterine Cytomegalovirus Infection: A Case Report.

BACKGROUND: Congenital cytomegalovirus (cCMV) infection can lead to a range of adverse outcomes. The majority of cCMV neonates with clinical symptoms are infected postnatally; however, established cases of intrauterine infection are uncommon, resulting in a paucity of reports on clinical findings and lymphocytes expression in CMV-infected neonates. CASE PRESENTATION: We followed a neonate with cCMV infection from the onset of hospitalization to several months of follow-up. This infant was intrauterine CMV-positive in the amniotic fluid of the mother at 21 weeks' gestation and received intravenous ganciclovir infusion and sequential oral valganciclovir after birth. The typical clinical signs manifested in the nervous system, liver, and peripheral blood and were documented during the hospitalizaion period and up to the follow-up visit. Flow cytometry was employed to examine the expression of T cells, their subsets, and the associated cytokines in peripheral blood samples at various time points. The flow data for the cCMV neonate were compared with those of the controls at each time point. Following treatment, clinical symptoms improved and the infant became CMV negative. However, developmental delays occurred later in life. The proportion of CD8+CD28- Tregs in the peripheral blood of the neonate with congenital CMV infection was higher than that in the controls at the three time points. The expression levels of perforin and granzyme B secreted by γδ T cells (Vδ1 and Vδ2 T cells), increased during the course of hospitalization until follow-up and were higher than those in the controls at the three time points. CONCLUSIONS: Despite the alleviation of clinical symptoms, developmental delay in later life remains inevitable in this intrauterine cCMV neonate. CD8+CD28- Tregs and Vδ1 and Vδ2 T cells secreting perforin and granzyme B may be involved in congenital CMV infection, although this hypothesis requires validation in a larger study. This report may contribute to our understanding of the effect of current treatment and the immune status of intrauterine cCMV-infected neonates.