VZV-specific Cell-mediated Immunity Research Articles

Baculovirus Vector-Based Varicella-Zoster Virus Vaccine as a Promising Alternative with Enhanced Safety and Therapeutic Functions.

Varicella-zoster virus (VZV) poses lifelong risks, causing varicella and herpes zoster (HZ, shingles). Currently, varicella and HZ vaccines are predominantly live attenuated vaccines or adjuvanted subunit vaccines utilizing VZV glycoprotein E (gE). Here, we propose our vaccine candidates involving a comparative analysis between recombinant baculoviral vector vaccines (AcHERV) and a live attenuated vaccine strain, vOka. AcHERV vaccine candidates were categorized into groups encoding gE only, VZV glycoprotein B (gB) only, or both gE and gB (gE-gB) as AcHERV-gE, AcHERV-gB, and AcHERV-gE-gB, respectively. Humoral immune responses were evaluated by analyzing total IgG, IgG1, IgG2a, and neutralizing antibodies. Cell-mediated immunity (CMI) responses were evaluated by enzyme-linked immunospot (ELISPOT) assay and Th1/Th2/Th17 cytokine profiling. In the mouse model, AcHERV-gE-gB elicited similar or higher total IgG, IgG2a, and neutralizing antibody levels than vOka and showed robust VZV-specific CMI responses. From the perspective of antigens encoded in vaccines and their relationship with CMI response, both AcHERV-gB and AcHERV-gE-gB demonstrated results equal to or superior to AcHERV-gE, encoding only gE. Taken together, these results suggest that AcHERV-gE-gB can be a novel candidate for alleviating risks of live attenuated vaccine-induced latency and effectively preventing varicella during early stages of life while providing strong CMI for effective resistance against HZ and therapeutic potential in later stages of life.

2158. Monitoring of Varicella specific T-cell mediated immunity in pediatric allogenic hematopoietic stem cell transplant recipients

Abstract Background Varicella-zoster virus (VZV) infection is known to occur in 13-55% of patients within the first year after hematopoietic stem cell transplant (HSCT). The dynamics of recovery of VZV-specific T cell- mediated immunity (CMI) and its role for prevention and control of VZV reactivation are rarely reported in pediatric allogenic HSCT recipients. Methods From April 2019 to February 2020, subjects aged younger than 19 years who underwent allogenic HSCT with at least 1 year of follow up at Asan Medical Center Children`s Hospital were prospectively enrolled. All of them underwent VZV-specific enzyme-linked immune absorbent spot (ELISPOT) assays just before HSCT and then at 1, 3 months following HSCT. Extension study, which measures VZV-specific CMI before and after VZV vaccination at 24 months post-HSCT, is currently underway. Results A total of 32 HSCT recipients with a median age of 11years were enrolled. 37.5% underwent haploidentical HSCT and VZV R+ were in 78.1%. Antiviral prophylaxis was applied to all HSCT recipients, of which 65.6% were applied up to 365 days after HSCT. During this study period, only 1 patient (3.1%) experienced herpes zoster at 23 months following HSCT, whose VZV-specific ELISPOT assay showed 0, 1, and 0 spot-forming cells (SFC)/2.0x105 cells before HSCT, 1 and 3 months following HSCT, respectively. The presence of VZV-specific CMI ≥ 1 SFC/ 2.0 × 105 cells was observed in 62.5 % before HSCT, 65.6 % at 1 month, 59.4 % at 3 months, and 70% at 24 months after HSCT, respectively. However, only 18.8 % ,12.5 % and 21.9 % recovered VZV-specific CMI with ≥ 5 SFC/ 2.0 × 105 cells at 1, 3 and 24 months following HSCT. Meanwhile, all the 4 recipients who got the 1st VZV vaccination at 24 months following HSCT showed recovery of VZV-specific CMI with ≥ 5 SFC/ 2.0 × 105 cell. Recovery of VZV-specific CMI after HSCT was not associated with VZV serostatus, chickenpox history, type of HSCT, conditioning regimens, and GVHD. Conclusion Only a few pediatric allogenic HSCT recipients recovered VZV-specific CMI with ≥ 5 SFC/ 2.0 × 105 cell up to 2 years following HSCT. In addition, the association between VZV-specific CMI and VZV reactivation could not be analyzed because no one experienced VZV reactivation within 1 year after HSCT. More long-term large-scale multicenter study is mandatory to supplement these parts. Disclosures All Authors: No reported disclosures.

Longitudinal changes in cell-mediated immunity after varicella-zoster virus skin test in the general population; Shozu Herpes Zoster Study: SHEZ study.

Varicella-zoster virus-specific cell-mediated immunity has been associated with the onset and severity of herpes zoster (HZ), and the administration of the HZ vaccine enhanced the immunity. However, limited data is available on the duration of cell-mediated immunity enhancement by soluble antigen of varicella-zoster virus (VZV) skin test. A prospective, community-based cohort study was conducted in Shozu County, Kagawa Prefecture, Japan. Repeated VZV skin tests containing inactivated VZV antigen and blood tests were performed on 365 subjects aged 60 years and older at baseline, 1, 2, and 3 years later. The differential immunity indices of VZV over time for cell-mediated and humoral immunity were evaluated.VZV skin test reaction and ELISpot counts increased significantly at 1, 2, and 3 years later compared to the baseline. However, humoral immunity indices did not change materially over time. Soluble antigen by VZV skin test enhanced VZV-specific cell-mediated immunity, and it persisted for at least 1 year. In addition, the inoculation with inactivated antigens every year by VZV skin test continued to enhance VZV-specific cell-mediated immunity after 2 and 3 years.

A Simple-to-Perform ifn-γ mRNA Gene Expression Assay on Whole Blood Accurately Appraises Varicella Zoster Virus-Specific Cell-Mediated Immunity After Allogeneic Hematopoietic Stem Cell Transplantation.

Herpes zoster, which is due to the reactivation of Varicella zoster virus (VZV), is a leading cause of morbidity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). While cell-mediated immunity (CMI) is critical to inhibiting VZV reactivation, CMI is not routinely assessed due to a lack of reliable tests. In this study, we aimed to evaluate VZV-specific CMI among allo-HSCT recipients (n = 60) and healthy individuals (HI, n = 17) through a panel of three immune functional assays after ex vivo stimulation by VZV antigen: quantification of (i) IFN-γ release in the supernatants, (ii) T-cell proliferation after a 7-day stimulation of peripheral blood mononuclear cells (PBMC), and (iii) measurement of the ifn-γ mRNA gene expression level after 24 h of stimulation of a whole-blood sample. VZV responsiveness was defined according to IFN-γ release from VZV-stimulated PBMC. Upon VZV stimulation, we found that allo-HSCT recipients at a median time of 6 [5-8] months post-transplant had lower IFN-γ release (median [IQR], 0.34 [0.12–8.56] vs. 409.5 [143.9–910.2] pg/ml, P <.0001) and fewer proliferating T cells (0.05 [0.01–0.57] % vs. 8.74 [3.12–15.05] %, P <.0001) than HI. A subset of allo-HSCT recipients (VZV-responders, n = 15/57, 26%) distinguished themselves from VZV-non-responders (n = 42/57, 74%; missing data, n = 3) by higher IFN-γ release (80.45 [54.3–312.8] vs. 0.22 [0.12–0.42] pg/ml, P <.0001) and T-cell proliferation (2.22 [1.18–7.56] % vs. 0.002 [0.001–0.11] %, P <.0001), suggesting recovery of VZV-specific CMI. Interestingly, VZV responders had a significant fold increase in ifn-γ gene expression, whereas ifn-γ mRNA was not detected in whole blood of VZV-non-responders (P <.0001). This study is the first to suggest that measurement of ifn-γ gene expression in 24-h-stimulated whole blood could be an accurate test of VZV-specific CMI. The routine use of this immune functional assay to guide antiviral prophylaxis at an individual level remains to be evaluated.

Equivalent Cellular and Humoral Immunity to Varicella Zoster Virus in Patients With Inflammatory Bowel Disease and Healthy Older Adults for Whom Immunization Is Recommended.

INTRODUCTION:Patients with inflammatory bowel disease (IBD) are at an increased risk of herpes zoster (HZ). HZ is caused by reactivation of the varicella zoster virus (VZV) and is prevented by strong VZV-specific cell-mediated immunity. The aim of our study was to evaluate whether patients with IBD had lower or equivalent protection compared with healthy controls (HCs) at age 50 years and older.METHODS:We performed a cross-sectional study at a single academic center and evaluated cellular and humoral immunity to VZV in patients with IBD at age 35–49 years vs HCs aged 50–59 years. All patients with IBD were on stable medication regimens for at least 3 months. VZV-specific cell-mediated immunity was measured via ELISPOT, and humoral immunity was measured via a quantitative VZV antibody enzyme-linked immunosorbent assay assay.RESULTS:Seventy-seven patients with IBD and 12 HCs were enrolled in the study. There was no significant difference in ELISPOT counts between patients with IBD and HCs (P = 0.54). In addition, there was also no significant difference between ELISPOT counts in immunosuppressed patients with IBD (N = 45) and HCs (P = 0.32). We also found no correlations between ELISPOT counts and age (Spearman rho 0.014; P = 0.90). Patients with IBD had similar IgG VZV antibody levels (median 19 mIU/mL; range 0.5–218) compared with HCs (median 23.5 mIU/mL (range 4–34); P = 0.54).DISCUSSION:Young patients with IBD have equivalent cellular and humoral immunity to VZV as healthy older adults in whom HZ immunization is recommended.

Clinical Manifestations of Herpes Zoster Associated with Complications in Children.

Herpes zoster (HZ) is caused by latent varicella-zoster virus (VZV) reactivation when VZV-specific cell-mediated immunity declines. Information on HZ in children is limited. Therefore, we retrospectively investigated HZ’s clinical course and complications in children. We extracted the outpatient and hospitalization medical records of pediatric patients (<19 years) primarily diagnosed with HZ (ICD-10 B02 code) between January 2010 and November 2020. HZ was defined as a typical unilateral dermatomal vesicular rash where HZ was the treating physician’s primary diagnosis. Recognized HZ complications included combined bacterial skin infection, ophthalmic zoster, zoster oticus without facial paralysis, meningitis, and PHN. We identified 602 HZ cases, among which 54 developed HZ complications and were included in our analysis. The median age was 14.7 years, most patients were aged ≥13 years (42, 79%), and none were aged <4 years. Fifty-three were immunocompetent, and only one had systemic lupus erythematosus. The most frequent complication was zoster ophthalmicus (n = 26, 48%). HZ complications were also observed in immunocompetent or vaccinated children exhibiting a head or neck rash before and after VZV immunization. Current VZV vaccination programs may be insufficient in preventing HZ complications. Therefore, close varicella and HZ burden monitoring and the establishment of effective VZV vaccination programs are imperative.

Prophylactic vaccination with a live-attenuated herpes zoster vaccine in lung transplant candidates

Herpes zoster (HZ) is caused by the reactivation of varicella-zoster virus (VZV). Patients with lung transplants are at high risk for HZ owing to their immunocompromised status and the need for lifelong immunosuppression. In this study, patients on the waiting list for lung transplantation were vaccinated by a live-attenuated HZ vaccine (Zostavax, Merck Sharp & Dohme), and the safety and immunogenicity of this vaccine were studied. In total, 105 patients with end-stage pulmonary disease (ESPD) were enrolled (68 participants received 1 dose of Zostavax and 37 participants were enrolled as unvaccinated controls). Among them, 43 patients underwent lung transplantation and were followed up for further analysis. VZV immunoglobulin G antibody titers and VZV-specific cell-mediated immunity (CMI) on multiple time points before and after vaccination and before and after transplantation were measured. Immune response to Zostavax was higher in younger patients, highest within 3 months after vaccination, and not influenced by gender or type of ESPD. Age, cytomegalovirus serostatus, and immunity to VZV at baseline impacted the subsequent immune response to the vaccine. Short-term immunosuppressant treatment had strong effects on VZV CMI levels, which returned to a high level at 6 months after transplantation in vaccinated patients. Zostavax did not impact infection or rejection rate after transplantation. Zostavax was safe and induced a robust humoral and cellular response for patients awaiting lung transplantation regardless of the type of ESPD. Patients younger than the recommended vaccination age of over 50 years showed a strong response and could also benefit from pre-transplant immunization.

Relationships of varicella zoster virus (VZV)-specific cell-mediated immunity and persistence of VZV DNA in saliva and the development of postherpetic neuralgia in patients with herpes zoster.

There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 6 cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.

Reactivation of Simian Varicella Virus in Rhesus Macaques after CD4 T Cell Depletion.

Rhesus macaques intrabronchially inoculated with simian varicella virus (SVV), the counterpart of human varicella-zoster virus (VZV), developed primary infection with viremia and rash, which resolved upon clearance of viremia, followed by the establishment of latency. To assess the role of CD4 T cell immunity in reactivation, monkeys were treated with a single 50-mg/kg dose of a humanized monoclonal anti-CD4 antibody; within 1 week, circulating CD4 T cells were reduced from 40 to 60% to 5 to 30% of the total T cell population and remained low for 2 months. Very low viremia was seen only in some of the treated monkeys. Zoster rash developed after 7 days in the monkey with the most extensive CD4 T cell depletion (5%) and in all other monkeys at 10 to 49 days posttreatment, with recurrent zoster in one treated monkey. SVV DNA was detected in the lung from two of five monkeys, in bronchial lymph nodes from one of the five monkeys, and in ganglia from at least two dermatomes in three of five monkeys. Immunofluorescence analysis of skin rash, lungs, lymph nodes, and ganglia revealed SVV ORF63 protein at the following sites: sweat glands in skin; type II cells in lung alveoli, macrophages, and dendritic cells in lymph nodes; and the neuronal cytoplasm of ganglia. Detection of SVV antigen in multiple tissues upon CD4 T cell depletion and virus reactivation suggests a critical role for CD4 T cell immunity in controlling varicella virus latency.IMPORTANCE Reactivation of latent VZV in humans can result in serious neurological complications. VZV-specific cell-mediated immunity is critical for the maintenance of latency. Similar to VZV in humans, SVV causes varicella in monkeys, establishes latency in ganglia, and reactivates to produce shingles. Here, we show that depletion of CD4 T cells in rhesus macaques results in SVV reactivation, with virus antigens found in zoster rash and SVV DNA and antigens found in lungs, lymph nodes, and ganglia. These results suggest the critical role of CD4 T cell immunity in controlling varicella virus latency.

Study of the natural course and specific immunity after herpes zoster in patients with rheumatoid arthritis receiving biologic DMARDs.

Herpes zoster is a common infection especially in elderly persons. It is caused by reactivation of varicella zoster virus (VZV) that has remained dormant within dorsal root ganglia after primary infection. Besides patients with immunodeficiency and malignancies, zoster incidence is also higher in patients with rheumatic diseases compared to the general population. Especially in the group of rheumatoid arthritis (RA) patients being treated with biologics, the risk seems to be steady among regimens with different modes of action (1.6–2.4/100 patients-years). RA patients receiving tumor necrosis factor (TNF) inhibitors are at increased risk during the first year of treatment. The aim of the current research protocol is to evaluate the natural course of herpes zoster and the effect of biologic and conventional synthetic disease modifying anti-rheumatic drugs (DMARDs) on the VZV-specific cell mediated immunity in RA patients after herpes zoster infection. We will – prospectively – include RA patients who develop herpes zoster, while being treated with biologics (anti-TNF, tocilizumab, rituximab, abatacept) and a control group comprised of patients with herpes zoster [RA patients under non-biologic therapies (corticosteroids/csDMARDs) and age- and sex-matched healthy controls). Titers of IgG specific antibodies against VZV glycoprotein gp1 and the percentage and absolute number of VZV-specific activated CD4+ T cells (CD4+CD69+IFN-γ+) at the time of rash onset and during follow-up will be measured by ELISA and flow cytometry respectively. This study will contribute to the better understanding of various aspects of immune response to VZV in the modern treatment era with biologic DMARDs.

Relationship between cell-mediated immunity to Varicella-Zoster virus and aging in subjects from the community-based Shozu Herpes Zoster study.

Age-related declines in cell-mediated immunity (CMI) are associated with the incidence and severity of Herpes Zoster (HZ) infection. However, the level of Varicella-Zoster virus (VZV)-specific CMI associated with disease onset is unclear. This study aimed to examine factors associated with VZV-specific CMI, as measured by an interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay, in a Japanese cohort. The study enrolled 365 subjects aged 60 years and over, all of whom were taking part in the Shozu Herpes Zoster (SHEZ) study and had undergone four sets of blood and intradermal reaction tests during a 3 year follow-up period. The VZV-specific immunity profile of each subject was assessed, and linear mixed effects models were constructed to analyze IFN-γ ELISPOT results in association with a combination of factors. The model that best explained the IFN-γ ELISPOT results was selected using the Akaike Information Criteria. The best-fit model consisted of age group as the only explanatory fixed-effect variable. The model showed that VZV-specific CMI, quantified as numbers of spots on the ELISPOT assay, among subjects aged 70-79 was on average 10.30 points lower than that among subjects aged 60-69. There was no statistically significant difference between subjects aged 70-79 and those aged 80-89. Age was the only factor significantly associated with the level of VZV-specific CMI, as measured by the IFN-γ ELISPOT assay. These results may represent an important step towards quantifying the relationship between VZV-specific CMI and the onset of HZ. J. Med. Virol. 89:313-317, 2017. © 2016 Wiley Periodicals, Inc.

Clinical and immunologic features of recurrent herpes zoster (HZ)

Recurrent herpes zoster (HZ) is thought to be rare, but there have been few large-scale studies of recurrent HZ. We conducted a large-scale prospective cohort study to characterize recurrent HZ. We examined 12,522 participants aged 50years or older in Shozu County and followed them up for 3years. We compared the incidence of HZ and postherpetic neuralgia, severity of skin lesions and acute pain, cell-mediated immunity, and varicella-zoster virus-specific antibody titer between primary and recurrent HZ. A total of 401 participants developed HZ: 341 with primary HZ and 60 with recurrent HZ. Skin lesions and acute pain were significantly milder and the incidence of postherpetic neuralgia was lower in patients aged 50 to 79years with recurrent HZ than in those with primary HZ. Varicella-zoster virus skin test induced a stronger reaction in patients aged 50 to 79years with recurrent HZ than in those with primary HZ. Information on previous HZ episodes was self-reported by participants, so it could not be confirmed that they actually had a history of HZ. Recurrent HZ was associated with milder clinical symptoms than primary HZ, probably because of stronger varicella-zoster virus-specific cell-mediated immunity in the patients with recurrence.

Varicella Zoster Virus in the Nervous System.

Varicella zoster virus (VZV) is a ubiquitous, exclusively human alphaherpesvirus. Primary infection usually results in varicella (chickenpox), after which VZV becomes latent in ganglionic neurons along the entire neuraxis. As VZV-specific cell-mediated immunity declines in elderly and immunocompromised individuals, VZV reactivates and causes herpes zoster (shingles), frequently complicated by postherpetic neuralgia. VZV reactivation also produces multiple serious neurological and ocular diseases, such as cranial nerve palsies, meningoencephalitis, myelopathy, and VZV vasculopathy, including giant cell arteritis, with or without associated rash. Herein, we review the clinical, laboratory, imaging, and pathological features of neurological complications of VZV reactivation as well as diagnostic tests to verify VZV infection of the nervous system. Updates on the physical state of VZV DNA and viral gene expression in latently infected ganglia, neuronal, and primate models to study varicella pathogenesis and immunity are presented along with innovations in the immunization of elderly individuals to prevent VZV reactivation.

Varicella-zoster virus-specific cell-mediated immunity and herpes zoster development in multiple myeloma patients receiving bortezomib- or thalidomide-based chemotherapy

BackgroundThe incidence of herpes zoster is substantial during bortezomib treatment in patients with multiple myeloma (MM). ObjectivesThis study aimed to elucidate the effect of chemotherapy with or without bortezomib in MM patients on their herpes zoster incidence and varicella zoster virus (VZV)-specific cell-mediated immunity (CMI). Study designPeripheral blood mononuclear cells were collected at baseline and after 1 month of bortezomib-based or thalidomide-based chemotherapy and then analyzed using VZV-specific interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay. The clinical data from these patients were analyzed in relation to the ELISPOT results. ResultsOf 58 patients analyzed, 39 patients received bortezomib and the other 19 patients, thalidomide. Among them, 5 patients developed herpes zoster during chemotherapy; all 5 were being treated with the bortezomib-based regimen and were not receiving prophylactic anti-viral agents. The median onset of herpes zoster was 32 days (range, 15–95 days) from the initiation of chemotherapy. Among patients who received bortezomib therapy, acyclovir prophylaxis significantly reduced the risk for herpes zoster (100-day cumulative incidence, 0% vs. 49.5%; p<0.001). Spot-forming cell (SFC) counts in the IFN-γ ELISPOT assay decreased from baseline after bortezomib (p=0.011) or thalidomide (p=0.096) treatment. Patients with baseline SFCs greater than 20/106 mononuclear cells exhibited significantly higher incidence of herpes zoster (100-day cumulative incidence, 34.8% vs. 0%; p=0.040). ConclusionsBortezomib treatment significantly reduced VZV-specific CMI, and high baseline SFC counts in patients receiving this treatment without acyclovir prophylaxis were associated with a significantly increased risk for herpes zoster.

Herpes zoster vaccination in the elderly subjects: improving awareness and uptake

Herpes zoster (HZ) is a common disease in adults and older subjects solely related to the reactivation of latent varicella zoster virus in ganglia. The incidence of the disease increases with aging and the decline of varicella zoster virus-specific cell-mediated immunity. HZ has a significant impact on the quality of life of subjects during the acute phase. Besides, pain can persist even for a long time becoming chronic. The chronic pain following HZ is called postherpetic neuralgia, and it is a debilitating long-lasting condition, characterized by metameric pain, allodynia, and hyperalgesia. Therapeutic options against HZ and postherpetic neuralgia are often suboptimal and the impact of the disease and its complications on daily living activities is significant, especially in older subjects. Nowadays, a preventive approach to the disease is possible; as a matter of fact, a high-antigen content live vaccine is available. This vaccine has a good profile in terms of immunogenicity, efficacy, effectiveness, and safety and its use may prevent both HZ and postherpetic neuralgia. Nevertheless, the evaluation of the issues raised in countries that introduced this immunization show that both provider and patient barriers could have prevented a more robust uptake of HZ vaccination. In the USA, HZ immunization storage was expensive, reimbursement was cumbersome, and supply shortages may have limited promotion by the interests of the manufacturer and provider. The doctors did not actively recommend HZ vaccination; on the other hand, subjects were mostly unaware of the HZ vaccine. Several demographic factors, including sex and educational level, could have negatively affected the coverage rates; besides, the clinicians who treat adults focus less on vaccination than those taking care of children. On the other hand, when health care profession- als undertook every effort to maximize the uptake of the shingles vaccine (eg, in the UK), the vaccine coverage rate increased very quickly.

Evaluation of varicella zoster virus-specific cell-mediated immunity by using an interferon-γ enzyme-linked immunosorbent assay

BackgroundAdministration of the varicella vaccine induces both varicella-zoster virus (VZV)-specific humoral and cell-mediated immunity (CMI). ObjectiveTo assess VZV-CMI, we developed an interferon γ enzyme-linked immunosorbent assay (IFN-γ ELISA) that measures the quantity of total IFN-γ in culture supernatants of human peripheral blood mononuclear cells. Study designWe evaluated this method by comparing the pre- and post-vaccination immune response in peripheral blood mononuclear cells of 30 healthy children who were administered an initial varicella vaccination at Konan Kosei hospital. ResultsIFN-γ ELISA showed well-validated results; CMI was not detectable pre-immunization but became detectable post-immunization. Seroconversion was detected in 92.6% of subjects by the immune adherence hemagglutination test; however, half of the subjects did not display an increase in CMI levels. We also compared the incidence of breakthrough varicella and herpes zoster development between CMI post-positive and post-negative vaccinees at 1–2years after the last VZV vaccination. Eight subjects had a history of varicella or herpes zoster exposure post-VZV vaccination. Two of them with post-negative CMI contracted breakthrough varicella 15–16months after the last vaccination, even though they had sufficient VZV-specific antibody levels to be considered seropositive and seroprotected. Conversely, the others with post-positive CMI did not contract breakthrough varicella, despite experiencing extensive VZV exposure through casual contact with playmates and family. ConclusionsThe CMI data generated by this IFN-γ ELISA may accurately reflect real-world immune status, and CMI may be closely related to immunoprotection against breakthrough varicella development.

Varicella-zoster virus-specific cell-mediated immunity in Ramsay Hunt syndrome.

The etiology of Ramsay Hunt syndrome (Hunt syndrome) is reactivation of latent varicella-zoster virus (VZV) in the geniculate ganglion of the facial nerve, leading to neuritis. Although the mechanism of the VZV reactivation is unclear, one possibility is that the reactivation involves a low level of VZV-specific cell-mediated immunity (CMI). The aim of this study was to clarify the characteristics of the VZV-specific CMI in Hunt syndrome compared to that in Bell's palsy, and to obtain clues to its role in the development of Hunt syndrome. Prospective study. We determined the median spot numbers and examined VZV-specific CMI in patients with Hunt syndrome and with Bell's palsy using interferon-γ enzyme-linked immunospot (ELISPOT) assays. We analyzed the relationship between the value of VZV-specific CMI and days from disease onset. The median spot number in Hunt syndrome (87.3 spot-forming cells [SFCs]/4 × 10(5) peripheral blood mononuclear cells [PBMCs]) was higher than that in Bell's palsy (62.3 SFCs/4 × 10(5) PBMCs). Hunt syndrome showed a strong relationship between the ELISPOT count and days from onset (r = 0.65). Within the first 5 days from onset, no ELISPOT counts higher than 80 SFCs/4 × 10(5) PBMCs were observed. On the other hand, no correlation was observed between the ELISPOT count and days from onset in patients with Bell's palsy (r = -0.19). These results suggest that VZV-specific CMI in Hunt syndrome is low at disease onset and increases rapidly thereafter. Consequently, reduced VZV-specific CMI may play an important role in the reactivation of VZV in the facial nerve, leading to Hunt syndrome.

VZV skin-test reaction, but not antibody, is an important predictive factor for postherpetic neuralgia

BackgroundThe decline of cell-mediated immunity (CMI) is thought to be related to the risk of postherpetic neuralgia (PHN) as well as herpes zoster (HZ). However, the relationship between immunological condition and the incidence of PHN is still unclear. ObjectiveWe conducted a large-scale prospective cohort study to clarify the relationship between immunological factors for varicella-zoster virus (VZV) and the incidence of PHN. MethodsWe carried out a cohort study on VZV immunity in a population living on an island cluster, Shozu County in Japan, and examined the people who developed HZ during a follow-up period of 3 years, with a focus on the relationship between cell-mediated and humoral immunity and the incidence of PHN. A total of 12,522 people over the age of 50 were enrolled in this study, and 401 registrants were diagnosed with HZ, including 79 PHN cases. We evaluated anatomical location and severity of skin lesion, acute pain severity, presence or absence of abnormal sensations, CMI assessed by VZV skin test, and VZV-specific antibody titer measured by serological tests. ResultsThe incidence of PHN was significantly associated with a weak response to the VZV skin test, as well as facial or lumbosacral localization of skin rash, severe skin lesion, severe acute pain, and presence of abnormal sensations, but not related to VZV-specific antibody titer. ConclusionThe incidence of PHN is significantly associated with the decline of VZV-specific CMI, but not related to VZV-specific humoral immunity.

Longitudinal Change of Varicella‐Zoster Virus‐Specific Cell‐Mediated Immunity in Hunt Syndrome and Bell's Palsy

Objectives: (1) Compare longitudinal changes of Varicella-zoster virus (VZV)-specific cell-mediated immunity (CMI) in Hunt syndrome with Bell’s palsy using IFN-γ enzyme-linked immunospot (ELISPOT). (2) Examine the role of VZV-specific CMI for VZV reactivation in the facial nerve in Hunt syndrome. Methods: This prospective study was conducted in our tertiary referral hospital between 2010 and 2013. Nineteen Hunt syndrome and 59 Bell’s palsy patients were enrolled. Mononuclear cells isolated from whole blood were incubated with VZV antigen in culture plates for 40 hours. Anti IFN-γ antibody was added and the ELISPOT system counted immunostained spots indicating VZV-specific CMI. The relationship between the spots and days from the onset of palsy were compared between Hunt syndrome and Bell’s palsy patients. Results: Immediately after the onset, the number of spots in the Hunt syndrome group was much lower than in the Bell’s palsy group, indicating low VZV-specific CMI. However, it increased rapidly and showed a strong positive relationship between the number of spots and days from the onset of palsy ( r = 0.64) in Hunt syndrome. Several months after the onset, the number of spots in Hunt syndrome decreased gradually. In contrast, the Bell’s palsy group showed no such relationship ( r = –0.22). Conclusions: These results suggest that low CMI to VZV may play an important role in VZV reactivation in the facial nerve, thus leading to facial palsy in Hunt syndrome. VZV vaccination is considered to be a candidate to promote VZV-specific CMI for the prevention of Hunt syndrome.

Development of an IFN-&amp;#947; ELISpot Assay to Assess Varicella-Zoster Virus-specific Cell-mediated Immunity Following Umbilical Cord Blood Transplantation

Varicella zoster virus (VZV) is a significant cause of morbidity and mortality following umbilical cord blood transplantation (UCBT). For this reason, antiherpetic prophylaxis is administrated systematically to pediatric UCBT recipients to prevent complications associated with VZV infection, but there is no strong, evidence based consensus that defines its optimal duration. Because T cell mediated immunity is responsible for the control of VZV infection, assessing the reconstitution of VZV specific T cell responses following UCBT could provide indications as to whether prophylaxis should be maintained or can be discontinued. To this end, a VZV specific gamma interferon (IFN-γ) enzyme-linked immunospot (ELISpot) assay was developed to characterize IFN-γ production by T lymphocytes in response to in vitro stimulation with irradiated live attenuated VZV vaccine. This assay provides a rapid, reproducible and sensitive measurement of VZV specific cell mediated immunity suitable for monitoring the reconstitution of VZV specific immunity in a clinical setting and assessing immune responsiveness to VZV antigens.