Cytomegalovirus seropositivity is associated with herpes zoster

The Wide Spectrum of Presentations of Cytomegalovirus Infection in Immunocompetent Hosts: An Exhaustive Narrative Review

CMV is a ubiquitous DNA virus that establishes infection and results in 40-100% seropositivity. Viral replication occurs following an acquired primary infection (or reinfection) or by the reactivation of life-long latency. In immunocompetent patients, CMV infection is mostly asymptomatic or mild and self-limited. However, an extensive review of the literature published up to April 2024 reveals that despite immunocompetence, CMV can cause a very large variety of clinical syndromes in any part of the gastrointestinal tract (the most common pattern), the central or peripheral nervous system, and the eyes, as well as hematological, pulmonary, cardiac, and cutaneous disease. Not uncommonly, more than one system is involved, and though the disease is often self-limited, treatment with intravenous ganciclovir or oral valganciclovir may be required, and in isolated cases, fatalities may occur. Thus, a potential CMV infection should be considered in the differential of myriad syndromes in non-immunocompromised patients. Associated systemic symptoms (fever, sweats, and weight loss), lymphocytosis, and hepatitis are not uncommon and can be a useful clue. Some populations, such as critically ill patients in intensive care, pregnant women, elderly patients, and those with inflammatory bowel disease, may be more susceptible. Moreover, the potential of past, latent CMV infection (i.e., CMV seropositivity) to be associated with significant cardiovascular morbidity and all-cause mortality years later is intriguing and requires further study. All these data indicate the outstanding importance of developing a vaccine against CMV, which hopefully will become available in the foreseeable future. Meanwhile, a solid diagnosis of active CMV infection can be quickly established (or ruled out) by widely available serology tests and PCR amplification, and clinicians in all disciplines need to be more aware of the diverse guises of CMV infection and remember to consider it in any host, including an immunocompetent one.

Lack of functional TCR-epitope interaction is associated with herpes zoster through reduced downstream T cell activation

The role of T cell receptor (TCR) diversity in infectious disease susceptibility is not well understood. We use a systems immunology approach on three cohorts of herpes zoster (HZ) patients and controls to investigate whether TCR diversity against varicella-zoster virus (VZV) influences the risk of HZ. We show that CD4+ T cell TCR diversity against VZV glycoprotein E (gE) and immediate early 63 protein (IE63) after 1-week culture is more restricted in HZ patients. Single-cell RNA and TCR sequencing of VZV-specific T cells shows that T cell activation pathways are significantly decreased after stimulation with VZV peptides in convalescent HZ patients. TCR clustering indicates that TCRs from HZ patients co-cluster more often together than TCRs from controls. Collectively, our results suggest that not only lower VZV-specific TCR diversity but also reduced functional TCR affinity for VZV-specific proteins in HZ patients leads to lower T cell activation and consequently affects the susceptibility for viral reactivation.

Can COVID-19 Increase the Risk of Herpes Zoster? A Narrative Review

Herpes zoster (HZ) is associated with substantial morbidity. It is caused by reactivation of the latent varicella zoster virus (VZV) following decline in cell-mediated immunity, which is commonly age-related, but also occurs in individuals with immunosuppressive diseases and/or treatment. Since coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has been associated with T cell immune dysfunction and there have been reports of HZ in COVID-19 patients, we have performed a review of available literature on whether COVID-19 could trigger HZ. We identified 27 cases of HZ following COVID-19, which most frequently occurred within 1–2 weeks of COVID-19, and the majority of cases had typical presentation. Atypical presentations of HZ were noted especially in patients with lymphopenia. It has been hypothesized that VZV reactivation occurs as a consequence of T cell dysfunction (including lymphopenia and lymphocyte exhaustion) in COVID-19 patients. Based on current evidence, which is limited to case reports and case series, it is not possible to determine whether COVID-19 increases the risk of HZ. Practitioners should be aware of the possible increased risk of HZ during the pandemic period and consider timely therapeutic and preventive measures against it.

Do varicella vaccination programs change the epidemiology of herpes zoster? A comprehensive review, with focus on the United States

Introduction: Policy-makers in many countries have been wary of introducing varicella vaccination programs because of concerns that reduced exposures to varicella-zoster virus could increase herpes zoster (HZ) incidence. The U.S. introduced varicella vaccination in 1996 and has empiric evidence regarding this concern. Areas covered: This comprehensive review provides background emphasizing the epidemiology of varicella and of HZ in the U.S. before and after the introduction of their respective vaccines. The epidemiology is complex, and interpretation is complicated by methodologic challenges, by unexplained increases in age-specific HZ incidence that preceded varicella vaccination, and by introduction of vaccines for prevention of HZ. Nonetheless, observations from studies using different platforms and designs have yielded consistent findings, suggesting they are robust. Expert opinion: There has been no evidence that the U.S. varicella vaccination program increased HZ incidence in the general adult population over baseline trends. Furthermore, HZ incidence in children is declining. The U.S. experience can inform the development of new generations of models to predict HZ trends. More importantly, it provides reassurance for countries considering varicella vaccination that an effective program can reduce varicella morbidity and mortality while reducing the likelihood of HZ among children, and potentially, over time, across the entire population.

Reduced NK cell IFN-γ secretion and psychological stress are independently associated with herpes zoster

The pathogenesis of herpes zoster is closely linked to reduced varicella-zoster virus-specific cell-mediated immunity. However, little is known about the interplay between natural killer cells and psychological stress in the pathogenesis of herpes zoster. This study aimed to investigate possible associations among natural killer cells, T cells and psychological stress in herpes zoster. Interferon-gamma secretion from natural killer cell, psychological stress events, stress cognition scale scores and cytomegalovirus-specific cell-mediated immunity were compared between 44 patients with herpes zoster and 44 age- and gender-matched control subjects. A significantly lower median level of interferon-gamma secreted by natural killer cells was observed in patients with a recent diagnosis of herpes zoster than in control subjects (582.7 pg/ml vs. 1783 pg/ml; P = 0.004), whereas cytomegalovirus-specific cell-mediated immunity was not associated with herpes zoster. Psychological stress events and high stress cognition scale scores were significantly associated in patients with herpes zoster (P<0.001 and P = 0.037, respectively). However, reduced interferon-gamma secretion from natural killer cell and psychological stress were not associated. In conclusion, patients with a recent diagnosis of herpes zoster display reduced interferon-gamma secretion from natural killer cells and frequent previous psychological stress events compared with controls. However, reduced natural killer cell activity is not an immunological mediator between psychological stress and herpes zoster.

Increased herpes zoster risk associated with poor HLA-A immediate early 62 protein (IE62) affinity

Around 30% of individuals will develop herpes zoster (HZ), caused by the varicella zoster virus (VZV), during their life. While several risk factors for HZ, such as immunosuppressive therapy, are well known, the genetic and molecular components that determine the risk of otherwise healthy individuals to develop HZ are still poorly understood. We created a computational model for the Human Leukocyte Antigen (HLA-A, -B, and -C) presentation capacity of peptides derived from the VZV Immediate Early 62 (IE62) protein. This model could then be applied to a HZ cohort with known HLA molecules. We found that HLA-A molecules with poor VZV IE62 presentation capabilities were more common in a cohort of 50 individuals with a history of HZ compared to a nationwide control group, which equated to a HZ risk increase of 60%. This tendency was most pronounced for cases of HZ at a young age, where other risk factors are less prevalent. These findings provide new molecular insights into the development of HZ and reveal a genetic predisposition in those individuals most at risk to develop HZ.

Multidisciplinary study of the secondary immune response in grandparents re-exposed to chickenpox

Re-exposure to chickenpox may boost varicella-zoster virus (VZV) immunity in the elderly. This secondary immune response is hypothesized to confer protection against herpes zoster. We longitudinally sampled 36 adults over the course of one year after re-exposure to chickenpox. The resulting 183 samples and those of 14 controls were assessed for VZV-specific T-cell immunity and antibody titres. The percentages of VZV-specific CD4+ IL-2-producing T-cells were increased in re-exposed grandparents compared to control participants up to 9 months after re-exposure. Using a longitudinal mixture modelling approach, we found that 25% and 17% of re-exposed grandparents showed a boosting of VZV-specific CD4+ IL-2-producing T-cells and VZV-specific antibodies, respectively. The antibody boosting occurred exclusively in cytomegalovirus (CMV) IgG-positive participants. CMV IgG-positive participants also had higher VZV IE62-specific CD4+ IFN-γ-producing T-cell percentages and VZV-specific antibody titres. The protective effect of re-exposure to chickenpox is likely limited, as boosting only occurred in 17–25% of the VZV re-exposed grandparents and for less than one year.

[Clinical presentations of Herpes Zoster Ophthalmicus (diagnosis and therapy)]

Approximately a quarter of the world's population at some point in life is at risk of developing shingles (Herpes Zoster). In 10-20% of cases the first branch of the trigeminal nerve gets involved (Herpes Zoster Ophthalmicus, HZO). Ophthalmic complications of HZO are able to cause a significant reduction in visual function.

AIM

To study and summarize clinical features of HZO (including the rate of complications and their nature) and to determine the relationship between clinical and laboratory data from these patients.

MATERIAL AND METHODS

The study included 133 patients with ophthalmic and neurological complications of HZO (group 1 (n=28) - retrospective analysis of outpatient records for the period 1995-2005; group 2 (n=95) - a prospective study for the period 2005-2015), who received a course of conservative treatment in either the Botkin City Hospital, branch № 1, or in the ophthalmic department of the Moscow herpes centre (Gerpeticheskiy Tsentr Ltd.). Laboratory tests were performed only in patients from group 2 and included: examination of biological fluids for six types of herpes viruses by polymerase chain reaction, examination of tears and urine for DNA of Chlamydia, Mycoplasma, and Ureaplasma, and serological blood testing for markers of herpes virus infection. Patients from group 1 were prescribed topical antiviral, antibacterial, and anti-inflammatory therapy, in rare cases - acyclovir per os. In group 2, the treatment included systemic antiviral medications and immune correction therapy. Anti-inflammatory therapy consisted of local and systemic non-steroidal agents (NSAIDs).

RESULTS

The most common ophthalmic complications of HZO in both groups were stromal keratitis and keratoiridocyclitis, neurological - III and VI cranial nerves palsies. The duration of the disease in the first group ranged from 2 months to 3 years; in the second group, patients were divided into two subgroups: subgroup A with the disease duration of no more than one month (n=81) and subgroup B with the disease duration from 1.5 to 9 months (n=14). Varicella-zoster virus (VZV) DNA was present in tears and/or other biological fluids of patients from group 2 in more than 70% of cases (n=67). Particularly, in 27.4% of cases the virus was isolated in two fluids and in 7.4% of cases - in three fluids. The duration of virus production in tears and other biological fluids (saliva, blood, and urine) ranged from 10 days to 4 months.

CONCLUSION

Topical non-steroidal anti-inflammatory drugs and systemic etiological treatment in case of intraocular inflammation in HZO patients may reduce the risk of severe consequences of VZV reactivation and help avoid recurrences later in life.

Latency for cytomegalovirus impacts T cell ageing significantly in elderly end-stage renal disease patients

The number of elderly patients with end-stage renal disease (ESRD) has increased significantly during the last decade. Elderly ESRD patients are vulnerable to infectious complications because of an aged immune system. Additional immunological ageing effects may be derived from the uraemic environment and cytomegalovirus (CMV) latency. Elderly patients may be affected by these factors in particular, but data in this age group are limited. To assess the degree of immunological ageing and proliferative capacity of T lymphocytes, 49 elderly ESRD patients (defined as aged ≥ 65 years) on the renal transplantation waiting list were recruited and compared to 44 elderly healthy individuals (HI), matched for age and CMV serostatus. CMV latency was associated with more highly differentiated CD4⁺ and CD8⁺ T cells in both elderly HI and patients. Elderly CMV seropositive ESRD patients showed a substantial reduction in the number of naive CD4⁺ and CD8⁺ T cells compared with age- and CMV serostatus-matched HI. Elderly ESRD patients also showed significantly decreased numbers of central memory CD4⁺ and CD8⁺ T cells compared with HI, independently of CMV serostatus. In addition, thymic output and relative telomere length of both CD4⁺ and CD8⁺ T cells were decreased in CMV seropositive ESRD patients compared with HI. The proliferative capacity of T cells was similar for patients and HI. Elderly ESRD patients have an advanced aged T cell compartment when compared to age-matched healthy controls, which is driven mainly by CMV latency.