Human Herpesvirus Research Articles

Development of KSHV vaccine platforms and chimeric MHV68-K-K8.1 glycoprotein for evaluating the in vivo immunogenicity and efficacy of KSHV vaccine candidates.

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 is an etiological agent of Kaposi's Sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. Considering the high seroprevalence reaching up to 80% in sub-Saharan Africa, an effective vaccine is crucial for preventing KSHV infection. However, vaccine development has been limited due to the lack of an effective animal model that supports KSHV infection. Murine Herpesvirus 68 (MHV68), a natural mouse pathogen persisting lifelong post-infection, presents a promising model for KSHV infection. In this study, we developed KSHV vaccine and a chimeric MHV68 carrying the KSHV glycoprotein, serving as a surrogate challenge virus for testing KSHV vaccines in a mouse model. Among KSHV virion glycoproteins, K8.1 is the most abundant envelope glycoprotein with the highest immunogenicity. We developed two K8.1 vaccines: K8.1 mRNA-lipid nanoparticle (LNP) vaccine and K8.126-87-Ferritin (FT) nanoparticle vaccines. Both induced humoral responses in immunized mice, whereas K8.1 mRNA LNP also induced T cell responses. Using BACmid-mediated homologous recombination, the MHV68 M7 (gp150) gene was replaced with KSHV K8.1 gene to generate chimeric MHV68-K-K8.1. MHV68-K-K8.1 established acute and latent infection in the lungs and spleens of infected mice, respectively. Mice immunized with K8.1 mRNA LNP or K8.126-87-FT showed a reduction of MHV68-K-K8.1 titer but not MHV68 wild type (WT) titer in the lung. In addition, viral reactivation of MHV68-K-K8.1 was also significantly reduced in K8.1 mRNA LNP-immunized mice. This study demonstrates the effectiveness of two vaccine candidates in providing immunity against KSHV K8.1 and introduces a surrogate MHV68 system for evaluating vaccine efficacy in vivo.IMPORTANCEKaposi's sarcoma-associated herpesvirus (KSHV) is a prevalent virus that establishes lifelong persistent infection in humans and is linked to several malignancies. While antiretroviral therapy has reduced Kaposi's Sarcoma (KS) complications in people with HIV, KS still affects individuals with well-controlled HIV, older men without HIV, and transplant recipients. Despite its significant impact on human health, however, research on KSHV vaccine has been limited, mainly due to the lack of interest and the absence of a suitable animal model. This study addresses these challenges by developing KSHV K8.1 vaccine with two platforms, mRNA lipid nanoparticle (LNP) and FT nanoparticle. Additionally, chimeric virus, MHV68-K-K8.1, was created to evaluate KSHV vaccine efficacy in vivo. Vaccination of K8.1 mRNA LNP or K8.126-87-FT significantly reduced MHV68-K-K8.1 titers. Developing an effective KSHV vaccine requires an innovative approach to ensure safety and efficacy, especially for the immunocompromised population and people with limited healthcare resources. This study could be a potential blueprint for future KSHV vaccine development.

Potential novel HIV-1 reverse transcriptase inhibitors: a modeling and evaluation approach

Human immunodeficiency viru (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS), a disease that severely weakens the immune system and makes patients more susceptible to infections. Although there is no definitive cure for HIV, advances in drug development offer promising prospects. In this study, we targeted HIV-1 reverse transcriptase by performing virtual screening (VS) to identify novel candidate compounds. From a database of compounds similar to the inhibitor thymidine-5'-triphosphate (TTP), three compounds (CID441663, CID123650073, and CID123789980) were selected for their docking scores, which outperformed those of the reference compound TTP (-6.2302 kcal/mol). These compounds were then subjected to ADMET, PASS, and DFT analyses. Interestingly, all three ligands showed a broad spectrum of predicted antiviral activity, including targets related to human herpes virus and HIV. Specifically, while TTP primarily targets HIV-1 reverse transcriptase, the top three ligands were predicted to target HIV-1 integrase, with CID441663 and CID123789980 displaying higher confidence in this target compared to CID123650073. These findings suggest that the candidate ligands should undergo further in vitro validation to determine their precise roles as inhibitors or antagonists, and to confirm their selective targeting of HIV-related proteins.

Phaleria macrocarpa Fruit Protein Aqueous Extract Affects Viral Entry, Virucidal Activity, and Progeny Release

Presence of acyclovir (ACV) resistant virus posed a major problem in treating virus infection. Alternative treatment with the ability to encounter infection of acyclovir-resistant virus is thus needed and possibly with a different mode of action from ACV. Hence, this study evaluates the antiviral effect of Phaleria macrocarpa (Scheff.) Boerl fruit protein aqueous extract (PMFPAE) against three different strains of human herpesvirus type-1 (HHV-1) including a clinical strain, a less pathogenic strain (KOS-1), and acyclovir (ACV) resistant mutant (UKM-1). PMFPAE displayed antiviral activity towards all the HHV-1 strains when post-treated with high selective indices (SIs) of 80.6, 50, and 35, respectively. Plaque reduction percentages were reduced in attachment and penetration assays following treatment with PMFPAE indicating the ability to deactivate the early phases of the HHV-1 replication cycle. The virucidal activity was also noted following treatment of the virus with PMFPAE and this is supported by damages to the virus envelope as observed by transmission electron microscopy (TEM). Incubation of virus-treated cells with PMFPAE for 24 hr, reduced progeny release in a dose-dependent manner. The study confirms the antiviral mode of action of P. macrocarpa fruit against HHV-1 strains and the ACV-mutant strain includes inhibition during virus entry represented as the early stages of viral replication, virucidal activity, and interfering with progeny release. PMFPAE mode of action is hence different from ACV and worthy for the development of future antiviral drugs.

An In Silico Approach to Discover Efficient Natural Inhibitors to Tie Up Epstein–Barr Virus Infection

Epstein–Barr virus (EBV), also known as human herpesvirus 4, is a member of the herpes virus family. EBV is a widespread virus and causes infectious mononucleosis, which manifests with symptoms such as fever, fatigue, lymphadenopathy, splenomegaly, and hepatomegaly. Additionally, EBV is associated with different lymphocyte-associated non-malignant, premalignant, and malignant diseases. So far, no effective treatment or therapeutic drug is known for EBV-induced infections and diseases. This study investigated natural compounds that inhibit EBV glycoprotein L (gL) and block EBV fusion in host cells. We utilised computational approaches, including molecular docking, in silico ADMET analysis, and molecular dynamics simulation. We docked 628 natural compounds against gL and identified the four best compounds based on binding scores and pharmacokinetic properties. These four compounds, with PubChem CIDs 4835509 (CHx-HHPD-Ac), 2870247 (Cyh-GlcNAc), 21206004 (Hep-HHPD-Ac), and 51066638 (Und-GlcNAc), showed several interactions with EBV gL. However, molecular dynamics simulations indicated that the protein–ligand complexes of CID: 4835509 (CHx-HHPD-Ac) and CID: 2870247 (Cyh-GlcNAc) are more stable than those of the other two compounds. Therefore, CIDs 4835509 and 2870247 (Cyh-GlcNAc) may be potent natural inhibitors of EBV infection. These findings can open a new way for effective drug design against EBV and its associated infections and diseases.

The role of herpesviruses in endometrial pathology: frequency of herpesvirus DNA detection in the endometrium, cervix and vagina in patients with chronic endometritis and endometrial hyperplasia

Introduction. Chronic endometritis (CE) is reported in 12% of patients with primary infertility. Herpesviruses are considered as one of the causes of CE.The aim of the study. To evaluate the frequency of herpesviruses DNA detection in endometrium, cervix and vagina in patients with chronic endometritis and endometrial hyperplasia.Materials and methods. 167 women of reproductive age were included in the study. Samples from the posterolateral wall of the vagina, cervix and endometrium were taken from each patient. The obtained samples were analyzed by real-time PCR for the presence of Herpes simplex viruses type 1 and 2 (HPV 1,2), Epstein-Barr virus (EBV), Cytomegalovirus (CMV) and Human herpesvirus type 6 (HHV6). Endometrial tissue was subjected to morphologic examination.Results. Depending on the morphology of endometrial biopsy, all patients were divided into three groups: with CE (N=53), with endometrial hyperplasia (EH, N=63), with normal endometrium (N=51). There were no statistically significant differences in the frequency of herpesvirus detection in endometrial, cervical, and vaginal samples. In endometrial samples, EBV was detected in 1 (1.9%) patient with CE (1.9%) and 1 (1.6%) patient with EH, HPV1,2 — in 1 (2%) woman with normal endometrial histology; DNA of other herpesviruses was not detected.Conclusions. The relationship between herpesvirus type, positive locus and the presence of endometrial pathology has not been established. The frequency of herpesvirus DNA detection in endometrial, cervical, and vaginal samples was not significantly different between the groups of women with CE, EH, and normal endometrial histology. Only 2 (1.7%) of endometrial samples with pathologic morphology were positive for DNA of herpesviruses, in both cases it was EBV.

Hematological Cancer and Viral Infection

Hematological cancer patients are particularly vulnerable to the morbidity and death caused by viral infections. But, it is not well known how common viral infections are or what effects they have on patients undergoing traditional nontransplant treatment. How severe and how long T-cell-mediated immune suppression is determines the variation in viral infection incidence and prognosis between patient groups. Topics covered in this mini-review article include late CMV infection, new viral pathogens (human herpesvirus-6, BK virus, adenovirus, and human metapneumovirus), advancements in molecular diagnostics, and the possibility of novel agents for viral prophylaxis (maribavir) or preemptive therapy (valganciclovir). The infections caused by these viruses have been extensively studied. If we want to understand the range of these viral diseases and come up with effective ways to prevent and cure them, we need well-designed prospective trials. Patients undergoing nontransplant treatment for hematological malignancies are at greater risk for viral infections; this is especially important given the rising use of drugs like alemtuzumab, which cause significant T-cell depletion.

Interleukin‐6 transcripts up‐regulation in lymph nodes from unicentric and multicentric Castleman disease

AbstractIntroductionCastleman disease (CD) represents a spectrum of heterogeneous lymphoproliferative disorders sharing peculiar histopathological features, clinically subdivided into unicentric CD (UCD) and multicentric CD (MCD) and presenting with variable inflammatory symptoms. Interleukin (IL)‐6 and other cytokines play a major role in mediating CD inflammatory manifestations. Although the local microenvironment seems to be among the major sources of hypercytokinemia, the precise cellular origin of IL‐6 production in CD is still debated.MethodsA series of five nodal CD of different subtypes (one UCD, two idiopathic MCDs [iMCDs], one HIV‐negative human herpesvirus 8 (HHV8)‐associated MCD, and one HIV‐positive HHV8‐associated MCD) and a non‐CD reactive control were tested using RNAscope analysis and a dual in situ hybridization (ISH)/immunohistochemistry technique, in order to quantify IL‐6 expression and its spatial distribution. Quantitative analyses of in situ mRNA were performed on digitalized slides using the HISTOQUANT software (3DHISTECH) and differences between cases were evaluated by the Kruskal‐Wallis test.ResultsRNA‐ISH documented increased IL‐6 expression in all CD lymph nodes, independently from clinical and pathological subtypes, however, the highest levels were found in HHV8+ cases and statistically significant differences in IL‐6 expression were found only between HHV8+ MCD and control case. Dual RNA‐ISH for IL6 coupled with immunohistochemistry analysis showed that IL‐6 was overexpressed in CD31‐positive endothelial cells in 5/5 CD tested cases but not in the control case.ConclusionOur findings suggest that nodal IL‐6 expression seems to be significantly upregulated in HHV8+ MCD, but a trend toward increased nodal IL‐6 expression was noticed also in UCD and iMCD‐not otherwise specified. CD31+ endothelial cells probably represent one of the major sources of IL‐6 production in the nodal microenvironment.

Adverse events associated with carbamazepine: a pharmacovigilance study using the FDA Adverse Event Reporting System

ABSTRACT Introduction Carbamazepine (CBZ) is a commonly used antiseizures medications (ASM), but its adverse drug reactions (ADRs) can impact the successful management of epilepsy. There are currently limited systematic studies on ADRs related to CBZ, necessitating further investigation. Areas covered Using the FDA Adverse Event Reporting System (FAERS) database , we extracted reports where CBZ was the primary suspect, conducting subgroup analyses stratified by sex and age. Four risk signal detection methods ROR, PRR, BCPNN, and EGBM were employed to systematically analyze the ADRs associated with CBZ. Expert opinion In the epilepsy population, ADRs related to CBZ often involve examinations, hereditary disorders, and infections. Subgroup analysis showed differences in ADR signals among male, female, elderly, and young patients. Human Herpesvirus 6 Infection and Dermatitis Exfoliative were consistent CBZ-induced ADRs, unaffected by age or sex. The study also identified previously overlooked ADRs such as bone metabolism abnormalities, ocular toxicity, and ototoxicity. Many ADRs linked to CBZ remain underreported. It is crucial to enhance monitoring and information dissemination about CBZ use in epileptic patients. Adjusting medication regimens for high-risk individuals, potentially incorporating acupuncture, traditional Chinese medicine, or alternative anti-seizure medications, should be considered when necessary.

Out-of-Hospital Infant Mortality Associated with Herpesviruses

Introduction. Infant mortality is a universally recognized indicator for social well-being of the population. There is a need for an in-depth analysis of the causes and factors leading to the death of infants at home, including determining the etiology of infectious diseases potentially causing death.The purpose of the study — to determine the implication of herpesviruses in infant out-of-hospital death.Materials and methods. Samples from autopsy material of 23 infants (blood, small intestine, heart, lungs, liver, brain), who died at home from various causes, were analyzed by PCR for the presence of viral DNA and RNA from herpesviruses, orthomyxoviruses, paramyxoviruses, picornaviruses, adenoviruses, coronaviruses, parvoviruses, as well as intestinal viruses.Results and discussion. Positive PCR results were found in 11 cases (43.5 %), of which herpesviruses DNA was detected in 10 cases. In these samples, cytomegalovirus predominated, in association with Epstein — Barr virus and human herpesvirus type 6. This association was detected in blood and internal organs samples from four infants diagnosed with generalized viral infection, and from two infants with acute respiratory viral infection. This suggests the presence of a causal relationship between the lethal outcome and the detection of these viruses. Not all infants showed clinical signs characteristic of generalized herpes infection. In one infant with hypertrophic cardiomyopathy, coronavirus, enterovirus and rotavirus DNA was found in samples of internal organs.Conclusion. Results showed the dominant role of the herpesviruses in out-of-hospital infant death cases.

Classic Kaposi sarcoma: Diagnostics, treatment modalities, and genetic implications - A review of the literature.

Classic Kaposi sarcoma (CKS) is a rare vascular disease mainly found in populations of Mediterranean origin. The pathogenesis involves Human Herpes Virus 8 (HHV8) and genetic mutations such as SNP309 in the MDM2 gene. The recently discovered BPTF mutation in cells of CKS patients demonstrated higher latency-associated nuclear antigen (LANA) staining and altered vital transcriptomics, implicating a potential role in tumorigenesis. This review explores the genetic underpinnings and treatments for CKS. A comprehensive literature search was conducted from 2004 to 2024, yielding 70 relevant papers. Ongoing clinical trials investigating novel treatments such as talimogene and abemaciclib were included in the search and presented in the results. Clinical diagnosis and treatment can be challenging as the number of studies on CKS and treatment modalities is limited. Treatment strategies vary by disease stage, with local therapies like surgical intervention and radiation therapy recommended for early stages, while systemic therapies are considered in cases of systemic disease. While advancements in CKS treatment offer hope, further studies on immunotherapy are warranted to broaden the therapeutic options, such as anti-bromodomain or BPTF-targeted therapy.

Rare Encounter: A Study of Oral Cavity Kaposi Sarcoma in Two Cases

Abstract Introduction/Objective Kaposi Sarcoma (KS) of the oral cavity, is an unusual vascular endothelial neoplasm and is the most common malignancy affecting the skin and internal organs in patients with AIDS. The tumor is caused by Human herpesvirus 8 (HHV-8). It rarely metastasizes and can be treated and totally cured by treating the AIDS disease. The oral cavity may be the only/ first site of KS, and therefore, is important in the diagnosis. The lesions present as multiple red-purple macules that develop into plaques or nodules. The hallmark microscopic features are spindle cell proliferation and irregular small, vascular slits, which often run parallel to the epithelium, as well as extravasated RBCs, with hemosiderin deposition and hyaline globules in 50% of lesions. HHV-8 nuclear staining is positive in all cases, which is crucial to differentiate it from other conditions with positivity for spindled cell markers: CD34, CD31, ERG, and FVIII R. The tumor can also be positive for lymphatic-specific markers (D2-40, LYVE-1, VEGFR3, and PROX1) Methods/Case Report We reviewed retrospectively archived cases from our TUH oral pathology database with available H&E slides diagnosed for Kaposi sarcoma between 2013 – 2023. We retrieved two confirmed cases, and we reviewed the slides and clinical information. Results (if a Case Study enter NA) Data were colleceted and analysed. Conclusion Incorporating Kaposi sarcoma into the differential diagnosis of pigmented red-purple vascular lesions in the oral cavity is of paramount importance. Detection of Kaposi sarcoma in this region bears significant prognostic implications, often serving as an initial sign of Kaposi sarcoma and indicating HIV infection. Lesions typically localize on the palate and gingiva. Heightened awareness of this clinical entity is crucial for facilitating early detection and treatment with antiretroviral drugs. Furthermore, the differential diagnosis for lesions with similar clinical presentations encompasses a broad spectrum, including benign conditions such as pyogenic granuloma, hemangioma, bacillary angiomatosis, and even granulation issue, as well as malignant tumors like angiosarcoma. It is noteworthy that considering Kaposi sarcoma in this context prompts pathologists to prioritize ordering stains for HHV-8. This diagnostic approach is supported by the exceptional sensitivity and specificity of HHV-8 stains, which exhibit 99% sensitivity and 100% specificity for diagnosing Kaposi sarcoma, while consistently yielding negative results in all other entities within the differential diagnosis.

Novel diagnostic method for B cell vitreoretinal lymphoma by identification of regulatory T cells and PD-1+ cytotoxic T lymphocytes in the vitreous via flow cytometry

AimsTo investigate the significance of regulatory T cells (Tregs) and programmed cell death 1 (PD-1)+ cytotoxic T lymphocytes (CTLs) in the vitreous of patients with vitreoretinal lymphoma (VRL) and uveitis.MethodsThis...

Human Herpesvirus-6B Infection and Alterations of Gut Microbiome in Patients with Fibromyalgia: A Pilot Study

Fibromyalgia (FM) is a chronic disorder characterized by widespread musculoskeletal pain often accompanied by fatigue, sleep disturbances, memory issues, and mood disorders. The exact cause of FM remains unknown, and diagnosis is typically based on a history of persistent widespread pain, as there are no objective biomarkers usable in diagnosis of this disorder available. The aim of this study was to identify measurable indicators specific to FM with potential as biomarkers. This study included 17 individuals diagnosed with FM and 24 apparently healthy persons. Using real-time polymerase chain reaction (qPCR), we detected the presence of human herpesvirus (HHV)-6A and B genomic sequences in DNA isolated from peripheral blood mononuclear cells (PBMCs) and buccal swabs. HHV-6-specific IgG and IgM class antibodies, along with proinflammatory cytokine levels, were measured using enzyme-linked immunosorbent assay (ELISA) and bead-based multiplex assays. Additionally, the gut microbiome was analyzed through next-generation sequencing. HHV-6B was more frequently detected in the PBMCs of FM patients. FM patients with a body mass index (BMI) of 30 or higher exhibited elevated cytokine levels compared to the control group with the same BMI range. Gut microbiome analysis revealed significant differences in both α-diversity and β-diversity between the FM and control groups, indicating a shift in species abundance in the FM group.

High-Throughput Transcriptomics Identifies Chemoresistance-Associated Gene Expression Signatures in Human Angiosarcoma

Angiosarcomas, clinically aggressive cancers of endothelial origin, are a rare subtype of soft-tissue sarcomas characterized by resistance to chemotherapy and dismal prognosis. In this study, we aim to identify the transcriptomic biomarkers of chemoresistance in angiosarcoma. We examined 72 cases of Asian angiosarcomas, including 35 cases treated with palliative chemotherapy, integrating information from NanoString gene expression profiling, whole transcriptome profiling (RNA-seq), immunohistochemistry, cell line assays, and clinicopathological data. In the chemoresistant cohort (defined as stable disease or progression), we observed the significant overexpression of genes, including SPP1 (log2foldchange 3.49, adj. p = 0.0112), CXCL13, CD48, and CLEC5A, accompanied by the significant enrichment of myeloid compartment and cytokine and chemokine signaling pathways, as well as neutrophils and macrophages. RNA-seq data revealed higher SPP1 expression (p = 0.0008) in tumor tissues over adjacent normal compartments. Immunohistochemistry showed a significant moderate positive correlation between SPP1 protein and gene expression (r = 0.7016; p < 0.00110), while higher SPP1 protein expression correlated with lower chemotherapeutic sensitivity in patient-derived angiosarcoma cell lines MOLAS and ISOHAS. In addition, SPP1 mRNA overexpression positively correlated with epithelioid histology (p = 0.007), higher tumor grade (p = 0.0023), non-head and neck location (p = 0.0576), and poorer overall survival outcomes (HR 1.84, 95% CI 1.07–3.18, p = 0.0288). There was no association with tumor mutational burden, tumor inflammation signature, the presence of human herpesvirus-7, ultraviolet exposure signature, and metastatic state at diagnosis. In conclusion, SPP1 overexpression may be a biomarker of chemoresistance and poor prognosis in angiosarcoma. Further investigation is needed to uncover the precise roles and underlying mechanisms of SPP1.

Infection risk with JAK inhibitors in dermatoses: a meta-analysis.

Evolving evidence suggests that Janus Kinase Inhibitors (JAKi) may predispose to certain infections, including tuberculosis and human herpes viruses. This review aimed to compare the infection risk in patients on a systemic JAKi for a dermatologic indication to a placebo. A systematic review was carried out from inception to June 2023, using the EMBASE, Medline, SCOPUS, and Cochrane Library of Registered Trials databases. Eligible studies included placebo-controlled randomized trials that investigated the incidence of infection in patients with a dermatologic indication. Primary outcomes included the most commonly reported infections pertaining to serious and opportunistic infections, upper respiratory tract infections, nasopharyngitis, herpes simplex, varicella zoster, tuberculosis, neutropenia, and lymphopenia. A meta-analysis of incidence ratios was conducted to determine odds ratios (OR), with a 95% confidence interval (CI) analysis. The meta-analysis found no increased risk of serious (OR: 0.92, 95% CI: 0.61-1.43, P = 0.74) or opportunistic infections (OR: 0.65, 95% CI: 0.32-1.31, P = 0.23). The incidence of varicella-zoster infections was significantly higher in the JAKi cohort (OR: 1.72, 95% CI: 1.08-2.72, P = 0.022). From 25 studies, there was no overall increased risk of herpes simplex infections (OR: 1.43, 95% CI: 0.93-2.23, P = 0.102) to placebo; however, a significantly higher risk in those with atopic dermatitis to alopecia areata was demonstrated (OR: 1.73, 95% CI: 1.13-2.69, P = 0.013). The results of this analysis do not suggest an increased risk of serious and opportunistic infections in those on JAKi compared to placebo. However, they support an increased risk of varicella-zoster infections and a higher risk of herpes simplex infections in those with atopic dermatitis to alopecia areata. The results of this report support these agents' short-term safety but signal that vigilance should be practiced in patients at risk for serious or recurrent herpes virus infections.

Chimeric antigen receptor-T-cell therapies going viral: latent and incidental viral infections.

Infections are the leading cause of non-relapse mortality following chimeric antigen receptor (CAR)-T-cell therapy, with viral infections being frequent both in the early and late phases post-infusion. We review the epidemiology of viral infections and discuss critical approaches to prevention and management strategies in this setting. Herpesviruses dominate the early period. herpes simplex virus and varicella zoster virus infections are rare due to widespread antiviral prophylaxis, but cytomegalovirus (CMV) reactivation is increasingly observed, particularly in high-risk groups including B cell maturation antigen (BCMA)-CAR-T-cell therapy recipients and patients receiving corticosteroids. While CMV end-organ disease is rare, CMV is associated with increased mortality, emphasizing the need to evaluate the broader impact of CMV on long-term hematological, infection, and survival outcomes. Human herpesvirus-6 (HHV-6) has also emerged as a concern, with its diagnosis complicated by overlapping symptoms with neurotoxicity, underscoring the importance of considering viral encephalitis in differential diagnoses. Respiratory viruses are the most common late infections with a higher incidence after BCMA CAR-T-cell therapy. Vaccination remains a critical preventive measure against respiratory viruses but may be less immunogenic following CAR-T-cell therapy. The optimal timing, type of vaccine, and dosing schedule require further investigation. A better understanding of viral epidemiology and preventive trials are needed to improve infection prevention practices and outcomes following CAR-T-cell therapies.

A-276 Unraveling Pathogen Dynamics In Pediatric Meningitis Complications During The Omicron Variant Outbreak In Taiwan

Abstract Background Taiwan, once celebrated for its remarkable control over COVID-19, faced an unexpected surge in pediatric cases during the first wave of the omicron variant in April 2022. Alarming data revealed acute encephalitis emerging in half of the severe or fatal COVID-19 cases in children within the initial two months of the omicron epidemic. This study delves into the intricate microbiota patterns and viral pathogens contributing to encephalitis complications in affected children. Methods The study enrolled 36 pediatric patients, comprising 11 patients with severe encephalitis, 12 patients with mild encephalitis, and 13 normal controls. Nasal swabs were collected for pathogen detection. For respiratory microbiota analysis, 16S rRNA metagenomic sequencing was employed, while the Illumina Respiratory Pathogen ID/AMR Enrichment Panel was used for respiratory pathogen identification. Results Microbiota analysis of nasal swabs from COVID-19 pediatric patients with meningitis complications revealed prevalent Corynebacterium, Staphylococcus, Dolosigranulum, Acinetobacter, Moraxella, and Streptococcus. Conversely. No predominant bacterial species were detected in the normal control group. Nasal swab respiratory pathogen detection identified coinfections, particularly Herpesviridae viruses such as human herpesvirus 6, Epstein-Barr virus, and Cytomegalovirus in pediatric patients with meningitis complications. Notably, two severe encephalitis cases exhibited coinfections involving rhinovirus, SARS-CoV-2, and Herpesviridae viruses (HHV-6, EBV). In one fatal case, distribution of Streptococcus genes among total geneomes reaches 40.69%, 7 drug resistant genes were detected. Conclusions This study suggests a potential link between latent Herpesviridae virus coinfections (HHV-6, CMV, EBV) and meningitis complications in pediatric patients. Furthermore, the presence of a secondary respiratory virus (rhinovirus) coinfection appears to be associated with severe complications. These findings shed light on the complex pathogen dynamics contributing to the emergence of encephalitis in pediatric COVID-19 cases during the omicron variant outbreak in Taiwan.

B-199 Rapid Molecular Detection of Meningitis Agents in Diverse Brazilian Regions (2019-2023): A Multicenter Study

Abstract Background Meningitis, caused by viral and bacterial agents, is a significant public health issue globally, with a substantial economic impact. In Brazil, the incidence of meningitis varies by region, making the identification of the causative agent crucial for effective treatment. This study aims to evaluate the epidemiology of meningitis agents diagnosed using a rapid molecular detection panel in samples from various hospital units of a nationwide diagnostic and healthcare company. Methods Samples from several hospitals across different regions of Brazil were analyzed using the FilmArray® rapid molecular panel for meningitis and encephalitis, capable of identifying up to 14 agents, including bacteria, viruses, and fungi/yeasts. Gender, age group, regional distribution, and agent prevalence from January 2019 to April 2023, were retrieved from the database ensuring compliance with the Brazilian Data Privacy and Protection (LGPD) and local Research Ethics Committee guidelines. Results The study included 485 patients from 41 cities across 11 Brazilian states. The age range was 0 to 96 years, with an average age of 45 years, and a majority of female participants (59%). The highest number of test requests occurred in 2022 (17.5%), followed by 2021 (10%), with 2019, 2020, and 2023 accounting for less than 5% of requests each. The overall positivity rate was 10.5% (51/485), with 92.8% (13/14) of the possible agents identified. Viral agents were detected in 60.7% of positive cases, bacterial agents in 39.2%, and one mixed infection (human herpesvirus 6 and Escherichia coli K1) in a 2-year-old child. No fungal/yeast infections were detected. The most common agents were varicella-zoster virus (18.2%), Haemophilus influenzae (12.7%), herpes simplex viruses type 1 and 2 (12.7% each), and enterovirus (12.7%). Conclusions The study highlights the importance of rapid molecular diagnostic methods in Brazilian clinical-laboratory practice, offering fast, safe, and sensitive detection of meningitis-causing agents, which can contribute to improved patient outcomes.

Assessment of human Herpes Virus-8 infection in Iranian cirrhotic patients on the waiting list for liver transplantation: A cross-sectional analysis

BackgroundHuman Herpes Virus 8 (HHV-8) is involved in autoimmunity. However, its association with advanced liver disease has not been fully explained. Herein, the prevalence of HHV-8 viremia was assessed in Iranian liver transplant candidates with a confirmed diagnosis of cirrhosis. MethodsThis cross-sectional study was conducted on 230 patients with cryptogenic cirrhosis, virus-related cirrhosis, and autoimmune hepatitis, as well as 140 healthy blood donors from April 2022 to September 2023. The HHV-8 IgG antibody concentration and viral load were evaluated via ELISA and RT‒PCR, respectively. ResultsAnti-HHV-8 IgG antibodies were detected in 25 cirrhotic patients (10.8 %) and four healthy individuals (2.6 %) (p = 0.022). The majority of the seropositive patients had cryptogenic cirrhosis (20.4 %), followed by autoimmune hepatitis (13.1 %) and virus-related cirrhosis (4.7 %). The seropositivity of HHV-8 IgG antibody was significantly different among the etiologies of liver cirrhosis (p = 0.011). However, HHV-8 genomic DNA was not detected in the sera of the patients or healthy blood donors. ConclusionThe role of HHV-8 infection in the development of posttransplant diseases, together with the higher seroprevalence of HHV-8 antibodies in cirrhotic patients than in healthy individuals, highlights the importance of both primary and latent infections in liver transplantation. Therefore, serological and molecular screening of HHV-8 is highly suggested for liver transplant candidates and organ donors. The possibility of antibody-mediated epitope mimicry in cryptogenic and autoimmune groups with moderate HHV-8 antibody positivity and negative viral loads may account for the development of advanced liver diseases.

Risk factors and long-term outcomes for human herpesvirus 6 encephalitis in the early period after allogeneic stem cell transplantation.

Human herpesvirus 6 (HHV6) encephalitis is a rare but life-threatening complication for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, reports on susceptibility factors and clinical outcomes are limited. We enrolled HHV6 encephalitis patients following allo-HSCT between 2018 and 2022, then conducted a 1:4 nested case-control cohort study to evaluate risk factors and long-term outcomes. Among 1350 patients, 20 (1.48%) developed HHV6 encephalitis, with a median onset time of 25.5 days after HSCT. Patient age<30 (odds ratio [OR], 3.24, P = 0.016) and NK cell count<115/ul at 21 days (OR, 6.07, P = 0.018) were identified as independent risk factors in multivariate analysis. Moreover, the HHV6 encephalitis group was significantly associated with higher incidence of grade II-IV graft-versus-host disease (aGVHD) (hazard ratio [HR], 5.52, P < 0.001) and transplant-associated microangiopathy (HR,9.86, P < 0.001), and demonstrated a significantly higher non-relapse mortality (NRM) (HR, 5.28, P = 0.004) and a lower overall survival (HR, 4.34, P = 0.001) or progression-free survival (HR, 3.94, P = 0.001) compared to control group. In conclusion, patients <30 years old or with delayed NK cell recovery are more susceptible to HHV6 encephalitis after allo-HSCT, and patients with HHV6 encephalitis after transplantation have poorer clinical outcomes.