Dynamic Immune Landscape and VZV-Specific T Cell Responses in Patients With Herpes Zoster and Postherpetic Neuralgia

Transcriptional and functional remodeling of lung-resident T cells and macrophages by Simian varicella virus infection

Introduction

Varicella zoster virus (VZV) causes varicella and can reactivate as herpes zoster, and both diseases present a significant burden worldwide. However, the mechanisms by which VZV establishes latency in the sensory ganglia and disseminates to these sites remain unclear.

Methods

We combined a single-cell sequencing approach and a well-established rhesus macaque experimental model using Simian varicella virus (SVV), which recapitulates the VZV infection in humans, to define the acute immune response to SVV in the lung as well as compare the transcriptome of infected and bystander lung-resident T cells and macrophages.

Results and discussion

Our analysis showed a decrease in the frequency of alveolar macrophages concomitant with an increase in that of infiltrating macrophages expressing antiviral genes as well as proliferating T cells, effector CD8 T cells, and T cells expressing granzyme A (GZMA) shortly after infection. Moreover, infected T cells harbored higher numbers of viral transcripts compared to infected macrophages. Furthermore, genes associated with cellular metabolism (glycolysis and oxidative phosphorylation) showed differential expression in infected cells, suggesting adaptations to support viral replication. Overall, these data suggest that SVV infection remodels the transcriptome of bystander and infected lung-resident T cells and macrophages.

PD-L1/PD-1 pathway: a potential neuroimmune target for pain relief

Pain is a common symptom of many diseases with a high incidence rate. Clinically, drug treatment, as the main method to relieve pain at present, is often accompanied by different degrees of adverse reactions. Therefore, it is urgent to gain a profound understanding of the pain mechanisms in order to develop advantageous analgesic targets. The PD-L1/PD-1 pathway, an important inhibitory molecule in the immune system, has taken part in regulating neuroinflammation and immune response. Accumulating evidence indicates that the PD-L1/PD-1 pathway is aberrantly activated in various pain models. And blocking PD-L1/PD-1 pathway will aggravate pain behaviors. This review aims to summarize the emerging evidence on the role of the PD-L1/PD-1 pathway in alleviating pain and provide an overview of the mechanisms involved in pain resolution, including the regulation of macrophages, microglia, T cells, as well as nociceptor neurons. However, its underlying mechanism still needs to be further elucidated in the future. In conclusion, despite more deep researches are needed, these pioneering studies indicate that PD-L1/PD-1 may be a potential neuroimmune target for pain relief.

Trigeminal Postherpetic Neuralgia: From Pathophysiology to Treatment

PURPOSE OF REVIEW

Trigeminal postherpetic neuralgia (TG-PHN) is a neuropathic pain condition complicating herpes zoster (HZ) attributed to the trigeminal nerve. It poses significant challenges due to its persistent and debilitating nature. This review explores the clinical characteristics of TG-PHN, analyzes its pathophysiological underpinnings, and addresses existent and potential therapies.

RECENT FINDINGS

TG-PHN is one of the most common and complex PHN locations. It has distinguishing clinical and pathophysiological characteristics, starting with viral triggered injuries to the trigeminal ganglion (TG) and peripheral tissue and involving the ascending and descending brain modulation pathways. Current therapies include vaccines, oral and topical medications, and interventional approaches, like nerve blocks and neurostimulation. This review covers TG-PHN's clinical and physiological components, treatment options, and potential future targets for improved management. By exploring the complexities of this condition, we aim to contribute to developing more effective and targeted therapies for patients suffering from trigeminal PHN.

Humoral Cytokine Levels in Patients with Herpes Zoster: A Meta-Analysis

Background

The neurocutaneous disease caused by the reactivation of varicella-zoster virus (VZV) is called herpes zoster (HZ). The virus remains in the spinal cord back root after the chickenpox disappears. Diminished immune function can reactivate VZV, causing severe neuropathic pain that can last for months or even years, leading to postherpetic neuralgia (PHN), which severely affects the patient's quality of life. Much literature compares various cytokine levels in the body fluids HZ and PHN patients; however, no studies comprehensively evaluate them.

Methods

The Cochrane Library, PubMed, Web of Science, and Medline were screened for studies on cytokine levels in body fluids of HZ and PHN patients in the English language. Healthy individuals were selected as the control group, and the standardized mean difference (SMD) between the case and control groups was imputed using a fixed-effects or random-effects model and expressed as a 95% confidence interval (CI). The Newcastle-Ottawa Scale (NOS) was used to assess article quality.

Results

This meta-analysis included 13 articles with 1373 participants. Compared with the control group, the HZ group had significantly higher levels of interleukin (IL)-4, IL-6, IL-10, Hcy, and C-reactive protein (CRP), whereas the levels of CD3+ T and CD4+ T lymphocytes were reduced. Additionally, PHN patients had significantly higher levels of IL-6 and IL-1β compared with the control group.

Conclusion

This meta-analysis provides compelling evidence that CRP, Hcy, IL-1β, IL-4, IL-6, IL-8, and IL-10 are associated with the genesis and development of HZ and PHN. These markers can be used to improve the diagnosis and treatment of these diseases.Furthermore, for making the results more convincing, it is necessary to harmonize sample acquisition techniques and analytical methods and also require larger, more rigorously designed studies with broader subgroups and sex/age-matched controls.

Acupoint herbal patching for postherpetic neuralgia: A systematic review and meta-analysis

BACKGROUND

This study aimed to systematically evaluate the clinical effectiveness and safety of acupoint herbal patching in the treatment of postherpetic neuralgia.

METHODS

Eight databases including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wan-Fang Database, China Biomedical Literature Service System, and Chongqing VIP Chinese Science were searched. The search time was set to October 2023. Two researchers independently screened the literature according to the inclusion and exclusion criteria; extracted the basic information, acupoints, Chinese herbal medicine, pain score, sleep score, depression score, and other information of the subjects, and independently assessed the risk of bias by 2 researchers. Meta-analysis of the included studies was performed using the StataMP 16 software.

RESULTS

Fifteen studies with 1362 participants were included in this meta-analysis. Ashi is the acupoint frequency at the forefront, and Borneol is the Chinese herbal medicine frequency at the forefront. The acupoint herbal patching group showed significant improvements in visual analog score (SMD: -2.09; 95% Cl: -2.77, -1.42; P < .001), sleep score (SMD: -1.58; 95% Cl: -2.11, -1.05; P < .001), depression score (SMD: -1.61; 95% Cl: -2.22, -0.99; P < .001), Chinese medicine syndrome score (SMD: -2.32; 95% Cl: -2.84, -1.80; P = .06), dermatology life quality index (weighted mean differences: -4.11; 95% Cl: -4.58, -3.63; P = .98), and related laboratory indicators compared to the control group, and the total effective rate was significantly higher (relative risk: 1.20; 95% confidence interval: 1.15, 1.26; P = .99) than the control group. Two studies reported adverse reactions, but the 2 groups were not statistically significant.

CONCLUSIONS

Acupoint herbal patching intervention in postherpetic neuralgia is effective in improving the pain, sleep, anxiety, depression, quality of life of patients, and related laboratory indicators.

Comprehensive Bibliometric Analysis of Research Articles on Post-Herpetic Neuralgia and Varicella-Zoster Virus: A 20-Year Review(2003-2022)

Objective

Post-herpetic neuralgia (PHN) is a debilitating condition that has garnered considerable attention from pain physicians due to its association with the or Varicella-Zoster Virus (VZV). In this study, we aimed to conduct a bibliometric analysis to quantitatively assess the research outcomes related to PHN and VZV over the past two decades (2003-2022).

Methods

We conducted a bibliometric analysis by querying the Web of Science database for articles related to PHN published from 2003 to 2022. In this analysis, we collected relevant information from the database including the number of publications, publication year, source, country, institution, and citation data.

Results

A total of 1073 publications were extracted from the database, with 387 articles (36.1%) being authored by individuals from the United States, making it the leading country in terms of article publications. The top ten institutions that made significant contributions to research on PHN and VZV were primarily concentrated within the United States. Notably, the New England Journal of Medicine and Pain claimed the two highest positions in terms of citation count, with 2482 and 1591 citations, respectively. The topics covered in these articles mainly revolved around "Postherpetic Neuralgia", "Herpes Zoster", "Epidemiology", "Vaccine", and "Quality-of-life".

Conclusion

Over the past two decades, there has been a gradual increase in publications on PHN and VZV, demonstrating significant advancements in academic achievements. Vaccines have proven effective in reducing PHN incidence among the elderly, but there is a lack of research on interventional treatments and underlying mechanisms. To elevate evidence-based medicine, researchers should conduct more controlled clinical trials. Additionally, leveraging pathogenesis research findings can lead to the development of better pain relief medications.

Serum Inflammatory Cytokine Levels in Herpes Zoster Patients and Their Association with Postherpetic Neuralgia: A Prospective Study

BACKGROUND This study aimed to investigate the serum levels of inflammatory cytokines in patients with herpes zoster (HZ) and to assess their correlation with the development of postherpetic neuralgia (PHN). Understanding this relationship may offer insight into the mechanisms of PHN and provide avenues for targeted treatment. MATERIAL AND METHODS We selected 169 patients diagnosed with HZ and 43 healthy controls (HCs) for the study. Serum levels of inflammatory cytokines were measured in all participants. Pain severity was evaluated using the visual analog scale (VAS). Based on follow-up data, the 169 HZ patients were categorized into 2 groups: those who developed PHN (HZ-PHN) and those who did not (HZ-Con). We then analyzed the differences in cytokine levels and their correlation with PHN development. RESULTS Compared to the HCs group, HZ patients exhibited a significant decrease in TNF-a levels and an increase in IL-10 levels (P<0.05, P<0.01). The VAS score was negatively correlated with TNF-alpha levels and positively correlated with IL-10 levels in HZ patients (r=-0.3081, P<0.01; r=0.5619, P<0.01). Distinctive levels of TNF-alpha, IL-6, IL-8, and IL-10 were observed among different pain groups (P<0.05, P<0.01). The HZ-PHN group showed lower TNF-alpha and higher IL-10 levels compared to the HZ-Con group (P<0.05, P<0.01). IL-10 level was identified as an independent risk factor for PHN, with a sensitivity and specificity of 76.4% and 54.3%, respectively. CONCLUSIONS Abnormal levels of inflammatory cytokines are present in HZ patients, and the IL-10 level may serve as a valuable indicator for predicting the risk of developing PHN.

Top 100 Most-Cited Papers in Herpes Zoster from 2000 to 2022: A Bibliometric Study

Background

In recent years, the incidence of herpes zoster has risen steeply, the exact pathogenesis of the acute pain and the transformation into postherpetic neuralgia are still obscure, and the absence of effective management remains a major therapeutic challenge. The purpose of this study was to perform a qualitative and quantitative bibliometric analysis of the 100 most cited papers on herpes zoster.

Materials and methods

Related literature were retrieved from the Web of Science Core Collection. Excel and VOSviewer software were applied to quantitatively analyze, and construct the bibliometric network charts.

Results

The Top 100 most-cited papers published between 2000 and 2018 showed a fluctuating downward trend. The most studies were published in the year of 2000 (n = 12). The article entitled "A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults" from Oxman MN, was the most-cited publication. The United States was the most contributing country, followed by the United Kingdom, and Italy. Finland occupied the highest citations per publication (CPP). The University of Colorado topped the list of institutions with the most publications with 18 articles and also had the most citations (average citations: 281.78 per article). Myron J Levin from the University of Colorado School of Medicine is the most published and most cited researcher overall, whereas Duke University's John W Gnann tops the list in terms of average CPP.

Conclusion

In terms of the quantity of T100 articles, researchers, and organizations, the US is the predominant country. The most T100 papers were published in the special journal Clinical Infectious Diseases. The most academic focus remain the remedies for postherpetic neuralgia and vaccine development for individualized groups.

Bidirectional two-sample Mendelian randomization analysis reveals a causal effect of interleukin-18 levels on postherpetic neuralgia risk

Background

Postherpetic neuralgia (PHN) is a debilitating complication of herpes zoster, characterized by persistent neuropathic pain that significantly impairs patients' quality of life. Identifying factors that determine PHN susceptibility is crucial for its management. Interleukin-18 (IL-18), a pro-inflammatory cytokine implicated in chronic pain, may play a critical role in PHN development.

Methods

In this study, we conducted bidirectional two-sample Mendelian randomization (MR) analyses to assess genetic relationships and potential causal associations between IL-18 protein levels increasing and PHN risk, utilizing genome-wide association study (GWAS) datasets on these traits. Two IL-18 datasets obtained from the EMBL's European Bioinformatics Institute database which contained 21,758 individuals with 13,102,515 SNPs and Complete GWAS summary data on IL-18 protein levels which contained 3,394 individuals with 5,270,646 SNPs. The PHN dataset obtained from FinnGen biobank had 195,191 individuals with 16,380,406 SNPs.

Results

Our findings from two different datasets of IL-18 protein levels suggest a correlation between genetically predicted elevations in IL-18 protein levels and an increased susceptibility to PHN.(IVW, OR and 95% CI: 2.26, 1.07 to 4.78; p = 0.03 and 2.15, 1.10 to 4.19; p =0.03, respectively), potentially indicating a causal effect of IL-18 protein levels increasing on PHN risk. However, we did not detect any causal effect of genetic liability to PHN risk on IL-18 protein levels.

Conclusion

These findings suggest new insights into identifying IL-18 protein levels increasing at risk of developing PHN and may aid in the development of novel prevention and treatment approaches for PHN.

T Lymphocyte Subsets Profile and Toll-Like Receptors Responses in Patients with Herpes Zoster

Purpose

Herpes zoster (HZ) is caused by the varicella-zoster virus (VZV), and 20% of healthy humans and 50% of people with immune dysfunction have a high probability of suffering from HZ. This study aimed to screen dynamic immune signatures and explore the potential mechanism during HZ progression.

Patients and Methods

Peripheral blood samples from 31 HZ patients and 32 age-sex-matched healthy controls were collected and analyzed. The protein levels and gene levels of toll-like receptors (TLRs) were detected in peripheral blood mononuclear cells (PBMCs) by flow cytometry and quantitative real-time PCR. Further, the characteristics of T cell subsets and cytokines were detected via a cytometric bead array.

Results

Compared to healthy controls, the mRNA levels of TLR2, TLR4, TLR7, and TLR9 mRNA in PBMCs were significantly increased in HZ patients. The protein level of TLR4 and TLR7 was significantly increased in HZ patients, but the levels of TLR2 and TLR9 were dramatically decreased. The CD3+ T cells were constant in HZ and healthy controls. CD4+ T cells were decreased in HZ patients, while CD8+ T cells were increased, resulting in an improved CD4+/CD8+ T cells ratio. Further, it was found that Th2 and Th17 were not changed, but the decreased Th1 and upregulated Treg cells were found in HZ. The Th1/Th2 and Th17/Treg ratios were significantly decreased. Last, the levels of IL-6, IL-10, and IFN-γ were significantly increased, but IL-2, IL-4, and IL-17A had no significant changes.

Conclusion

The dysfunction of host's lymphocytes and activation of TLRs in PBMCs were the important mechanism in varicella-zoster virus induced herpes zoster. TLRs might be the core targets for the therapy drug development in treating HZ.