Selective decline in cellular immune response to varicella-zoster in the elderly

Factors influencing pain outcome in herpes zoster: an observational study with valaciclovir. Valaciclovir International Zoster Assessment Group (VIZA)

AIM OF THE STUDY

An observational study with valaciclovir was conducted to assess clinical outcome in herpes zoster, especially pain and associated neurological signs and symptoms in relation to a series of demographic and disease characteristics discernible at presentation. The safety and acceptability of valaciclovir for treatment of zoster was assessed in a wide variety of primary care and clinic referral settings.

METHODS

In total, 1897 immunocompetent adults with clinically diagnosed, localized acute herpes zoster were enrolled in this international, open-label study of valaciclovir. All subjects received treatment with oral valaciclovir (1000 mg three times daily) for 7 days from entry to the study and were asked to record the presence of zoster-associated pain and abnormal sensations throughout treatment and 6 months' follow-up. They were seen frequently in clinic to verify subjective assessments and for evaluation of rash healing. Safety and tolerability were assessed by adverse event monitoring.

RESULTS

Overall, 1191 subjects (63%) were aged > or = 50 years, and 203 (11%) had ophthalmic zoster. Cessation of zoster-associated pain was significantly faster in the younger age group; median times to loss of zoster-associated pain were 23 days and 9 days in the > or = 50 and < 50 years age groups, respectively. Similarly, abnormal sensations resolved significantly more rapidly in the younger subjects; the median duration of abnormal sensations was 31 days in the > or = 50 year olds and 16 days in those aged < 50 years. In cases of ophthalmic zoster, the rate of pain resolution was not different from those with zoster in other dermatomes (median duration of pain 18 vs. 16 days). However, abnormal sensations persisted significantly longer in subjects with ophthalmic zoster than in those with zoster at other sites (47 vs. 22 days). In addition to advancing age, subjects suffering moderate to severe prodromal pain or acute pain during the rash phase were at significantly greater risk of zoster-associated pain and abnormal sensations persisting for longer. Subjects with concomitant neurological disorders were also more likely to develop prolonged abnormal sensations. Valaciclovir treatment was well tolerated, and adverse events were rare and generally mild.

CONCLUSION

This study confirmed the prognostic importance of advancing age and the intensity of prodromal or acute pain as risk factors for prolonged zoster-associated pain and persisting abnormal sensations in the affected dermatome. Ophthalmic zoster and pre-existing neurological disorders are also identified as highly significant risk factors for prolonged abnormal sensations in herpes zoster.

Varicella zoster viral disease

Herpes zoster is cause of considerable morbidity, especially among elderly patients, with a suggestion of a slight increase in incidence among female patients. Substantial research on the biology of the varicella zoster virus has led to advances in our knowledge of the pathophysiology of the disease along with more successful therapy for the acute episodes of herpes zoster. Ophthalmic zoster is more common than zoster in other cranial nerves and is associated with pronounced suffering. This article reviews the epidemiology, biology, and latency of herpes zoster, discusses the pathophysiology of the disease, and describes treatment options with antivirals and corticosteroids. The pathophysiology and treatment options for postherpetic neuralgia are also addressed. The varicella vaccine is now available, and initial results suggest that this may lessen the effect of herpes zoster in the future.

Spinal epidural abscess associated with epidural catheterization: report of a case and a review of the literature

We describe a 53-year-old man who developed a catheter-related epidural abscess 8 days after left upper lobectomy for lung cancer. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in a culture of the epidural pus. Magnetic resonance imaging was essential for the diagnosis of epidural abscess and for determining the extent of spread. The patient was treated by laminectomy and administration of appropriate antibiotics, with almost complete recovery, except for urinary retention. A literature search yielded 29 additional cases of catheter-related epidural abscess. The median duration of catheterization was 4 days and the median time to onset of the clinical symptoms after catheter placement was 8 days. Eleven of the 30 patients had some underlying disorders, including malignancy or herpes zoster, or were receiving steroids. Nine of the 10 patients with thoracic epidural abscess had persistent neurological deficits, whereas 12 of the 15 patients with lumbar epidural abscess showed a full recovery after treatment. Surgical decompression was not required in six patients without significant neurological deficits, who recovered following antibiotic treatment (four patients) or percutaneous drainage (two patients). Thoracic catheters are associated with a disproportionately high incidence of epidural abscess and persistent neurological sequelae following treatment.

Comparative study of transfer factor and acyclovir in the treatment of herpes zoster

Reactivation of varicella herpes virus (VHV), latent in individuals who have previously suffered varicella, gives rise to herpes zoster and in some cases leads to a sequela of post herpetic neuritis with severe pain which is refractory to analgesics. Many different antiviral agents have been tried without achieving satisfactory results. Of all the antiviral agents employed, acyclovir has been the most successful in reducing post herpetic pain. However acyclovir has not been as reliable as interferon alpha (IFN-alpha). We have previously looked into the use of transfer factor (TF) as a modulator of the immune system, specifically with respect to its effectiveness in the treatment of herpes zoster. In this work findings from a comparative clinical evaluation are presented. A double blind clinical trial of TF vs acyclovir was carried out in which 28 patients, presenting acute stage herpes zoster, were randomly assigned to either treatment group. Treatment was administered for seven days and the patients were subsequently submitted to daily clinical observation for an additional 14 days. An analogue visual scale was implemented in order to record pain and thereby served as the clinical parameter for scoring results. The group treated with TF was found to have a more favorable clinical course, P < or = 0.015. Laboratory tests to assess the immune profile of the patients were performed two days prior and 14 days after initial treatment. The results of these tests showed an increase in IFN-gamma levels, augmentation in the CD4+ cell population but not the percentage of T rosettes in the TF treated group. These parameters were however insignificantly modified in patients receiving acyclovir. Although TF treated patients showed an increase in CD4+ counts these cells remained below the levels for healthy individuals. The fact that IFN-gamma levels as well as the counts for CD4+ cells rose in the TF treated group and not in the acyclovir one is very significant and confirms the immunomodulating properties of TF.

Race and stress in the incidence of herpes zoster in older adults

OBJECTIVES

To examine the effect of black race and acute (negative life events) and chronic (lack of social support) psychological stress on the risk of herpes zoster in late life.

DESIGN

A population-based, prospective cohort study.

SETTING

Central North Carolina.

PARTICIPANTS

Duke Established Populations for Epidemiological Studies of the Elderly, a stratified probability sample of community-dwelling persons more than 65 years of age.

MEASUREMENTS

Interviewers administered a comprehensive health survey to the participants in 1986-1987 (P1, n = 4162), 1989-1990 (P2, n = 3336), and 1992-1994 (P3, n = 2568). Incident cases of zoster between P1 and P2 and P2 and P3 served as the dependent variable. Hypothesis-testing variables included race, negative life events, and five measures of social support. Control variables included age, sex, education, cancer, chronic diseases, basic ADLs, instrumental ADLs, depression, self-rated health, hospitalization, and cigarette smoking. Statistical analyses employed chi-square tests and proportional hazards model.

RESULTS

At baseline, the sample had a mean age of 73.6 years and was 55% black, 45% white, and 65% female. There were 65 cases of zoster between P1 and P2 and 102 cases of zoster between P2 and P3. From P1 to P2, 1.4% of blacks and 3.4% of whites developed zoster (P < .001). From P2 to P3, 2.9% of blacks and 7.5% of whites developed zoster (P < .001). After controlling for the above variables, blacks were significantly less likely to develop zoster (adjusted risk ratio = 0.35; 95% confidence interval (CI), 0.24-0.51; P < .001). Negative life events increased the risk of zoster, but the result was borderline for statistical significance (adjusted RR = 1.38, 95% CI 0.96-1.97; P = .078). No measures of social support were significantly associated with zoster.

CONCLUSION

Black race decreased the risk of zoster in late life significantly. Measures of stress were not significantly related to zoster, but study limitations preclude definitive conclusions. Future research should focus on these factors in larger samples and different populations.

Herpes zoster ophthalmicus in patients with human immunodeficiency virus infection

PURPOSE

To investigate the ocular complications of herpes zoster ophthalmicus in patients with human immunodeficiency virus (HIV) infection.

METHODS

This was a retrospective cohort study of 48 HIV-infected patients (48 eyes) treated at San Francisco General Hospital for herpes zoster ophthalmicus from December 1985 through March 1994.

RESULTS

All patients were initially treated with either intravenous or oral acyclovir. The median CD4 lymphocyte count at diagnosis was 48 per mm3 (range, 2 to 490 per mm3). Fifteen patients (31%) had mild or no ocular involvement. Seventeen patients (35%) had stromal keratitis, mostly mild, and two (4)% developed chronic infectious pseudodendritic keratitis. Twenty-four study patients (50%) had iritis, but only three (6%) had elevations in intraocular pressure. Two patients (4%) developed postherpetic neuralgia, and two others (4%) had zoster-associated central nervous system disease. Only two patients (4%) developed necrotizing retinitis, both in the form of the progressive outer retinal necrosis syndrome.

CONCLUSIONS

Excluding the patients with retinitis and central nervous system disease, the rate of sight-threatening complications in our series was lower than expected. Almost one third of study patients had no ocular complications or only mild surface epithelial disease. Although the relatively low incidence of sight-threatening disease in our study population may have been a consequence of aggressive management with acyclovir, chronic infectious pseudodendritic keratitis, retinitis, and central nervous system disease, complications of ophthalmic zoster whose pathogenesis is largely a consequence of active viral replication, were particularly devastating and difficult to manage.

Primary and secondary alterations of immune reactivity in the elderly: impact of dietary factors and disease

The function of the immune system declines with age. It is the aim of the present review to demonstrate that it makes sense to distinguish between primary and secondary alterations of immune reactivity in the elderly. Primary changes occur as the result of an age-dependent intrinsic decline of immune responsiveness. They also occur in healthy persons, i.e. persons selected according to the criteria of the SENIEUR protocol of the European Community's Concerted Action Program on Aging (EURAGE). T lymphocytes are hereby more severely affected than B cells or antigen presenting cells, possibly due to the involution of the thymus, which is almost complete at the age of 60. Secondary immunological changes occur as the result of environmental factors including diet, drug intake, physical activity etc. or are alternatively due to underlying diseases. In this article, the effects of high lipid intake as well as the impact of diseases, such as for instance Alzheimer's disease and atherosclerosis, will be addressed. The results underline the complexity of immunological alterations to be expected in old age. Changes in the aging immune system represent an opportunity for increased frequency and severity of disease and endanger the protective effect of vaccination.

The aging immune system: primary and secondary alterations of immune reactivity in the elderly

The function of the immune system is known to decline in the elderly. The present communication will show that, similar to the situation in children, it is necessary to distinguish between primary and secondary alterations of the immune reactivity in the elderly. The primary immunological change in the elderly is the age-dependent intrinsic decline of immune responsiveness that is also observed in healthy persons, i.e., those selected according to the criteria of the SENIEUR Protocol of EURAGE (European Community Concerted Action on Aging). Secondary immunological changes are due to underlying diseases and various environmental factors, including diet, drug intake, physical activity, etc. While primary immunodeficiencies of the elderly are not, or only to a very minor extent, presently influenced by therapeutic measures, secondary alterations of the immune function offer further possibilities for corrective measures. Clinically, the consequences of impaired immune function in the elderly include increased susceptibility to infectious disease, the emergence of tumors, and increased autoimmune reactions, the latter albeit often without concomitant autoimmune disease. In fact, autoimmune diseases in generally begin to develop at younger ages, but their consequences are major factors affecting the quality of life of the elderly. Investigations of basic molecular and cellular aspects of the aging immune system are, therefore, of theoretical, clinical and socioeconomic interest.

Impaired specific cellular immunity to the varicella-zoster virus in patients with herpes zoster oticus

The possible involvement of depression on cellular immunity in reactivation of varicella-zoster virus (VZV) in herpes zoster oticus was investigated. The subjects comprised 59 cases of herpes zoster oticus, 33 cases of herpes zoster sine herpete (ZSH) with facial paralysis, and 205 cases of Bell's palsy. The transformation rate of lymphocytes to phytohaemagglutinin in herpes zoster oticus tended to be lower than that in Bell's palsy. In skin tests with purified protein derivatives of tuberculin, the positivity rate in herpes zoster oticus was significantly lower than that in Bell's palsy (p < 0.015). In skin tests using VZV antigen the positivity rate in herpes zoster oticus and ZSH were significantly lower than that of Bell's palsy (p < 0.001 and p < 0.015, respectively). Thus, it was noted that cellular immunity, especially specific cellular immunity against VZV, was significantly depressed in herpes zoster oticus and ZSH. We consider that depression of specific cellular immunity plays an important role in triggering reactivation of VZV and onset of these diseases.

Pain and its persistence in herpes zoster

The nature and duration of pain associated with herpes zoster is highly variable. This review of research on pain in acute herpes zoster and postherpetic neuralgia (PHN) explores those observations relevant to the definition and pathogenesis of PHN and the design of treatment trials. A model for the pathogenesis of PHN is presented, which gains support from studies of risk factors. Several directions for future research are identified.

The varicella vaccine. Prevention of herpes zoster

The live attenuated varicella vaccine offers some hope that the frequency or severity of herpes zoster might be reduced. Universal immunization with this vaccine should result in less latent varicella-zoster virus in dorsal root and cranial nerve ganglia than that which occurs following varicella. Moreover, the vaccine virus is not well adapted for growth in human cells at normal body temperature. Thus, reduced virus for reactivation, and less robust replication, may lessen the problem of herpes zoster in vaccinees. For those individuals who have already had varicella, the risk of herpes zoster is closely related to the loss of varicella-zoster virus cell-mediated immune responses, which decline with aging (or immune suppression). In aging individuals these immune responses can be enhanced by booster immunization with the varicella vaccine, suggesting that a vaccine to prevent herpes zoster is feasible.

Clinical trials of varicella vaccine in healthy children

The Oka varicella vaccine has been tested in clinical trials worldwide in thousands of children. Following licensure in Japan, Korea, Germany, and the United States, the vaccine has been used in several millions of children. The vaccine has been generally well-tolerated with the most common complaints being pain and redness at the injection site and a mild rash following vaccination. The incidence of herpes zoster has not increased in vaccinees and may have decreased. Efficacy rates vary between 65% and 100% depending on the intensity of exposure to natural varicella and the potency of the vaccine. In those few vaccinees who develop MVLS, the rash is generally milder than seen following natural infection (median < 50 versus 300 lesions, respectively, as well as a lower incidence of fever). There has been no evidence to date to indicate waning immunity postvaccination. Studies are in progress in the United States to evaluate whether this will occur and the effect of booster doses of vaccine. It is expected that in countries where there is widespread use of the vaccine in healthy children, disease rates will fall dramatically as will the morbidity and mortality associated with natural varicella in this population.

Human herpes viruses latent infection in the nervous system

The neurotropic herpes viruses, HSV-1, HSV-2 and VZV, colonize and establish latent infection in human peripheral sensory ganglia. Recurrent diseases due to reactivation of these viral pathogens can take place despite an effective immune response. Molecular, cellular, physiological and immune mechanisms work in concert to enable the establishment of latency, the maintenance of the latent state for the entire life of the host, and the reactivation infection. Although all three viruses belong to the same family and establish latent infection in the same tissue, the clinical pattern of their reactivation is quite different. This review covers current knowledge of the basis of these infections, and offers a theory explaining the basis of HSV-1 latent infection and the differences of the disorders caused by HSV-1 and VZV reactivation in humans.

Varicella-zoster virus

Varicella-zoster virus (VZV) is a ubiquitous human alphaherpesvirus that causes varicella (chicken pox) and herpes zoster (shingles). Varicella is a common childhood illness, characterized by fever, viremia, and scattered vesicular lesions of the skin. As is characteristic of the alphaherpesviruses, VZV establishes latency in cells of the dorsal root ganglia. Herpes zoster, caused by VZV reactivation, is a localized, painful, vesicular rash involving one or adjacent dermatomes. The incidence of herpes zoster increases with age or immunosuppression. The VZV virion consists of a nucleocapsid surrounding a core that contains the linear, double-stranded DNA genome; a protein tegument separates the capsid from the lipid envelope, which incorporates the major viral glycoproteins. VZV is found in a worldwide geographic distribution but is more prevalent in temperate climates. Primary VZV infection elicits immunoglobulin G (IgG), IgM, and IgA antibodies, which bind to many classes of viral proteins. Virus-specific cellular immunity is critical for controlling viral replication in healthy and immunocompromised patients with primary or recurrent VZV infections. Rapid laboratory confirmation of the diagnosis of varicella or herpes zoster, which can be accomplished by detecting viral proteins or DNA, is important to determine the need for antiviral therapy. Acyclovir is licensed for treatment of varicella and herpes zoster, and acyclovir, valacyclovir, and famciclovir are approved for herpes zoster. Passive antibody prophylaxis with varicella-zoster immune globulin is indicated for susceptible high-risk patients exposed to varicella. A live attenuated varicella vaccine (Oka/Merck strain) is now recommended for routine childhood immunization.

DHEAS as an effective vaccine adjuvant in elderly humans. Proof-of-principle studies

We have demonstrated that in aged mice, the titer of serum antibody induced against tetanus toxoid correlates with resistance to local paralysis caused by injection of tetanus toxin. Only mice immunized shortly after oral dosing with DHEAS demonstrated high serum antibody titers and complete protection from paralysis. These results became the basis for initiating proof-of-principle studies in human volunteers above age 65 using a licensed influenza vaccine and tetanus toxoid in two independent studies. The use of an oral delivery form of DHEAS before influenza vaccination was associated with a demonstrable increase in the number of individuals with a fourfold increase in HAI titers following vaccination. The overall mean increase in HAI titers was highest in the DHEAS-treated group. The use of DHEAS in the immunization of elderly subjects against tetanus toxoid, while unable to enhance the responses, was not a detriment to antibody response. We conclude that further studies will justify the use of DHEAS as an adjuvant for antigens that represent primary responses in the elderly.

Boosting immune response with a candidate varicella-zoster virus glycoprotein subunit vaccine

A varicella-zoster virus (VZV) seropositive individual was immunized with 100 micrograms of purified VZV TgpI-511 glycoprotein subunit antigen formulated with monophosphoryl lipid A. Serum samples were obtained during a 40-day period post-immunization (PI) and analysed by immunoprecipitation and virus neutralization tests. The results from immunoprecipitation studies revealed an increase in VZV anti-gpI antibody titer as early as 6 days PI which continued to rise during 40 days PI. In addition, virus neutralization tests showed a 21.0% VZV neutralization 6 days PI with an increase to a 96.7% VZV neutralization 40 days PI. These results suggested that the candidate VZV glycoprotein subunit vaccine (TgpI-511) was capable of boosting the production of neutralizing antibodies in the immunized VZV seropositive human subject.

Cytokine production in varicella zoster virus-stimulated limiting dilution lymphocyte cultures

Human blood lymphocytes were stimulated with varicella zoster virus (VZV) antigen in limiting dilution cultures and the amounts of interferon-gamma (IFN-gamma) and IL-4 measured in the supernatants. The results indicate that up to 85% of proliferating cells of young adults produce IFN-gamma and up to 10% make IL-4. At limiting dilution, few if any wells were positive for both IFN-gamma and IL-4. The amount of IFN-gamma per well increased in the presence of antibody to IL-4, but anti-IFN-gamma not increase IL-4 production. The frequency of wells containing IFN-gamma was lower in subjects < 19 or > 55 years of age, and the amounts of IFN-gamma in positive wells was significantly lower in cultures of the older subjects' lymphocytes. The frequency of IL-4-making cells did not fall significantly with age. The data suggest that the age-related decline in the frequency of blood T cells which responds to VZV affects mainly the cells with a Th1-like cytokine phenotype.

A molecular and cellular model to explain the differences in reactivation from latency by herpes simplex and varicella-zoster viruses

There are marked similarities in the biological properties of the human neurotropic herpesviruses herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV), including their ability to establish lifelong latent infections in human peripheral sensory ganglia (PSG). Despite this, their patterns of reactivation are quite different: HSV-1 reactivations occur many times during a lifetime, they are localized to the cutaneous distribution of a single sensory nerve, they are not associated with sensory symptomatology and their frequency decreases with age. VZV recurrence on the other hand is usually a single event which tends to appear with advancing age, its cutaneous eruption involves an entire dermatome and is usually extremely painful. To help explain these differences, we have formulated a model based on current knowledge of the molecular and cellular basis of latent infection in the nervous system. We suggest that the amount of latent viral DNA and RNA in the latently infected tissue (higher with HSV-1), the cellular location of latent virus (neuronal in HSV-1, probably non-neuronal in VZV), the presence or absence of viral replication in the PSG during reactivation together with the host immune response, are all key determinants of the clinical expression of viral reactivation.

Varicella-zoster virus DNA in recurrent aphthous ulcers

The present study was undertaken to examine for varicella-zoster virus (VZV) constituents in recurrent aphthous ulcers (RAU). Smears and biopsies of ulcers 0-3 days old were obtained from 20 otherwise healthy minor/major RAU patients and from two patients with Behçet's syndrome. VZV could not be cultivated from any of the biopsies, all smears were negative for VZV antigen, and in situ hybridization on the five samples tested was negative for VZV nucleic acid. DNA extracted from biopsies, however, yielded positive polymerase chain reaction (PCR) products in all cases with one primer set of the protein kinase 66 (PK66). Ten control biopsies from non-RAU subjects yielded no PCR products apart from the sample from AP, who obtained the biopsies, and from HOM, who performed the PCR, suggesting that the DNA had been passed on from the patients. Other parts of the PK66 gene and of thymidine kinase 36 yielded no products. Although the consistent presence of VZV DNA in RAU might suggest a pathogenetic implication, the potential presence and possible pathogenetic importance of other herpesviruses cannot be excluded.

Investigations of the lymphokine system in elderly individuals

Elderly people are at risk from an increased incidence of infections. Therefore we have studied the correlation between the production of several immunological parameters such as interferon-gamma (IFN-gamma), interferon-alpha-2 (IFN-alpha-2), interleukin-2 (IL-2), soluble interleukin-2 receptors (sIL-2R) and interleukin-6 (IL-6) in young controls of 25-34 years old and old individuals with a minimum age of 65 years. All persons were selected according to the basic concept of the 'Senieur protocol'. Heparinized blood was taken and cultured in the whole-blood assay. The determination of all cytokines in the supernatants of stimulated cultures was done by the ELISA technique. We found significantly decreased levels of sIL-2R and IFN-alpha-2 after stimulation, whereas the values of IFN-gamma and IL-2 showed no significant difference between elderly and young persons. The values of IL-6 showed a distinct trend towards an increased synthesis for the elderly. We also studied the lymphocyte subpopulations T4 and T8 by flow cytometry. Elderly individuals showed a significantly increased T4/T8 ratio, caused by a slightly but not significantly decreased level of T8 cells. These results show that the elderly have decreased values of some immunological parameters such as IFN-alpha-2 and sIL-2R, which might explain an increased susceptibility of elderly individuals to bacterial and viral infections.

T-lymphocyte subsets in otherwise healthy patients with herpes zoster and relationships to the duration of acute herpetic pain

T-lymphocyte subsets (CD3, CD4, and CD8 lymphocytes) in peripheral blood, parameters of cell-mediated immunity, were serially measured in 62 otherwise healthy Japanese patients with herpes zoster (HZ), and the findings were compared with those of 20 age-matched healthy controls who had had varicella but not HZ. Our objective was to elucidate whether there were changes in cell-mediated immunity, even in immunocompetent patients with HZ, and to investigate relationships between these variables and the duration of acute herpetic pain (AHP). All the patients underwent repeated sympathetic nerve blocks until pain was relieved. As compared with controls, there were slight increases in the percentages of CD4 lymphocytes (helper/inducer) and highly significant increases in the percentages of CD8 lymphocytes (suppressor/cytotoxic), resulting in marked decreases in CD4/CD8 ratios in the acute phase of HZ. The percentages of CD3 lymphocytes (pan-T lymphocytes) did not differ significantly. The duration of AHP was analyzed in 49 patients in whom T-lymphocyte subsets were measured more than twice. There was a weak but statistically significant positive linear correlation between age and the duration of AHP (r = 0.43, P < 0.01). There were statistically highly significant positive linear correlations between the number of days on which percentages of CD3 (r = 0.72, P < 10(-8)) and CD4 lymphocytes (r = 0.60, P < 10(-5)), and CD4/CD8 ratios (r = 0.62, P < 10(-5)) reached the maximum values after the onset of HZ and the duration of AHP. These correlation coefficients were higher than that between age and the duration of AHP.(ABSTRACT TRUNCATED AT 250 WORDS)

The epidemiology of varicella-zoster virus infections: a mathematical model

Herpes-zoster is caused by the reactivation of varicella-zoster virus (VZV). In this paper different hypotheses of how this re-emergence of virus comes about are reviewed and discussed. From these hypotheses, and epidemiological data describing the initial transmission of the virus, a mathematical model of primary disease (varicella) and reactivated disease (zoster) in developed countries is derived. The steady-state age distributions of zoster cases predicted by this model are compared with the observed distribution, derived from a review and analysis of published epidemiological data. The model allows differentiation between published hypotheses in which age of host may or may not influence the probability of viral reactivation. The results indicate that the probability of reactivation must increase with age to allow the observed pattern of zoster cases. The basic mathematical model presented provides a conceptual framework, which may be extended to assess possible control programmes.

Low antibody avidity in elderly chickenpox patients

A small outbreak of chickenpox confirmed serologically in 3 elderly patients from a geriatric home is described. Disease was probably due to exogenous reinfection, yet nevertheless the avidity of specific antibodies measured by the urea denaturation test was even lower than in primary chickenpox controls, which themselves were, as expected, significantly lower than zoster controls. In elderly individuals susceptibility to reinfection with varicella-zoster virus (VZV) with clinical manifestation such as chickenpox may well be associated with the decay of specific humoral immunity detectable by antibodies of particularly low avidity, in contrast to reactivation of latent VZV presenting clinically as zoster, which is related to deficiencies in specific cellular immunity.

Serologic response and reactogenicity to booster immunization of healthy seropositive adults with live or inactivated varicella vaccine

The immunogenicity and reactogenicity of live and heat-inactivated varicella vaccine were evaluated in 95 healthy seropositive adults (mean age, 32 yrs). Live-attenuated vaccine containing 28,000 pfu, 2800 pfu, or 280 pfu of Oka/Merck strain virus (8.4, 0.84, and 0.08 antigen units, respectively) or heat-inactivated vaccine with comparable antigen content (7.1, 0.71, and 0.07 antigen units) was administered subcutaneously to 15 to 16 adults per group in a randomized, single-blind study. ELISA antibody responses were dose-dependent but independent of whether the vaccine was live or inactivated. Mean titers reached a peak on day 14 and remained elevated through day 42 in recipients of the highest dosages but declined by followup at eleven months. A minority of vaccinees developed a four-fold or greater increase in antibody titer on day 14 (25 to 31 percent in the high-dose groups [greater than or equal to 7.1 antigen units], less than or equal to 7 percent of other groups). The vaccine was generally well tolerated. Localized erythema and swelling occurred at the injection site in 44 to 56 percent of the high- and middle dose recipients [greater than or equal to 0.71 antigen units], compared with 0 to 6 percent of those receiving the lowest dose. Although statistically significant increases in varicella antibody titer were observed after immunization with high doses of live or inactivated vaccine, the duration and clinical significance of this booster effect remains to be determined.

Diagnosis and therapy of herpes zoster ophthalmicus

Studies in the basic and clinical sciences have yielded new information about the biology, infection, latency, and recurrence of the varicella-zoster virus. Contrast is made with the herpes simplex virus. The host-viral relationship is an extremely dynamic one with clinical disease being determined primarily by the host cellular immune system. The complications of herpes zoster ophthalmicus are related to multiple mechanisms including viral growth, vascular and neural damage, and the host-immune response to infection. There are several laboratory tests available for confirming the diagnosis or determining the immune status. Systemic acyclovir administered early in the course alleviates many of the symptoms of herpes zoster ophthalmicus. Acute and postherpetic neuralgia remain significant and enigmatic problems; an update of therapeutic options is offered. The role of corticosteroids in herpes zoster ophthalmicus is scrutinized along with the potential and uncertainties of a varicella-zoster virus vaccine.

Are stressful life events risk factors for herpes zoster?

To determine if psychologically stressful life events are risk factors for herpes zoster, we conducted a case-control study of zoster and self-reported recent negative life events and major changes in spousal relationships. The subjects were 101 healthy community-dwelling cases of zoster and 101 healthy controls matched for age, sex, and race and generated by random digit dialing. The Geriatric Scale of Recent Life Events was administered to case and control subjects, and additional questions were asked regarding the perception of the life event. The results showed that case subjects experienced negative life events significantly more often than subjects in the control groups in the 2 months before zoster onset by analysis of discordant pairs (26 versus 10, odds ratio 2.60, 95% confidence interval [CI] 1.13, 6.27, P = .012), 3 months before (29 versus 11, odds ratio 2.64, 95% CI 1.20, 6.04, P = .007), or 6 months before (35 versus 16, odds ratio 2.00, 95% CI 1.04, 3.93, P = .012). The mean number of total life events was significantly higher in cases at 6 months before zoster (case means = 2.64, control means = 1.82, P = .008), but there were no significant differences at 2, 3, or 12 months before. There were no significant differences between case subjects and control subjects for spousal events, or any given single life event. In conclusion, we found that whereas patients with herpes zoster experienced the same kinds of life events in the year preceding the illness as did control subjects, recent events perceived as stressful were significantly more common among patients with zoster.(ABSTRACT TRUNCATED AT 250 WORDS)

[HIV seropositivity in patients with herpes zoster]

Relationship between zoster and seropositivity for HIV is studied. Serum samples from 66 patients presenting acute zoster infection were tested for HIV antibodies, using ELISA. There was no previous selection of patients, what rendered the population studied unbiased. Seven patients (10.6%) were positive for HIV antibodies. Among them six belonged to AIDS risk groups, all were males and six had ages between 19 and 39 years (mean age value 31.7). Results suggest that the finding of zoster in younger age groups is not necessarily linked to HIV infection. When zoster is diagnosed in patients who belong to AIDS risk groups, independently from their age, the association with HIV infection is statistically significative. In these cases zoster can even be considered as a marker for HIV infection and it is mandatory to test these patients for HIV antibodies.

High incidence of herpes zoster in patients with systemic lupus erythematosus: an immunological analysis

The incidence of herpes zoster was determined in patients with systemic lupus erythematosus (SLE) and the cellular and humoral immunity to varicella zoster virus (VZV) investigated in 45 of these 92 patients. The incidence of herpes zoster was high, occurring in 40 patients (43%), though it was benign in all. Patients with SLE who had had zoster showed significantly higher antibody titres than normal subjects. On the other hand, only 13 of 43 (30%) patients with SLE showed positive delayed hypersensitivity skin reactions to VZV antigen, despite a history of infections with VZV, whereas all 15 normal subjects had positive reactions. Skin reactions to VZV correlated directly with the ratio of OKT4+ to OKT8+ T cells and inversely with the dose of corticosteroids. These results suggest that the high incidence of herpes zoster in patients with SLE is probably due to defects in cellular immunity and that normal or higher titres of antibodies to VZV will not act as a preventive against zoster. In addition, reactivation of VZV, whether symptomatic or not, seemed often to occur in patients with SLE.

Viral vaccines of the future

Varicella vaccine seems close to licensure in the United States. It is likely to be recommended for routine use in healthy children, either administered singly or as a combination of MMR. Healthy children who have been immunized develop excellent antibody and cell-mediated responses to VZV in the absence of significant adverse effects, and they are well protected against subsequent infection with VZV. Although it will not be known for certain for many years, it seems most unlikely that immunization will result in an increased incidence of zoster, a secondary type of infection with VZV that is caused by reactivation of latent VZV. Varicella vaccine may also be given to healthy adults who have never had chickenpox with a great degree of success, although its protection is somewhat less effective than in children. Leukemic children who are at high risk for developing severe or fatal varicella also derive a great deal of protection from varicella vaccine, but the vaccine must be administered to them with great caution. Other viral vaccines that may be licensed in the future but that are not as fully developed as varicella vaccine include vaccines against CMV, hepatitis A, HSV, and AIDS. These are in various degrees of study, and, should any of them be licensed, it is uncertain whether they would be live attenuated, recombinant, or subunit vaccines. It is hoped, however, that they will eventually be licensed for future use because if effective, they could significantly decrease morbidity and mortality of infants, children, and adults.

Cimetidine as an immunomodulator in the treatment of herpes zoster

As there is evidence of a possible immunoregulatory role for H2-histamine receptor antagonists, we carried out a prospective randomized trial to evaluate the in vivo and in vitro effect of cimetidine, an H2-blocker, in the treatment of herpes zoster infection. Cimetidine treatment shortened the median interval until the first decrease in pain, the median interval until the complete resolution of pain and promoted faster complete healing of skin lesions than symptomatic treatment. The immunological trends observed in vitro support an important role for histamine in the induction of immunosuppression, as measured by the response to the mitogen phytohemagglutinin. This effect of histamine was antagonized by cimetidine.

Severe herpes zoster infection in the United Kingdom: experience in a regional infectious disease unit

Seventy-three cases of severe herpes zoster infection admitted to a regional infectious disease unit over a 3-year period were reviewed. Complications were common. Elderly patients were in the majority (55%), were hospitalized for longer and accounted for 78% of all complications. Acyclovir therapy was used in 44 cases with a reduction in both the duration of hospital stay and complication rate.

Systemic lymphoproliferative responses to rotavirus

In comparison with healthy adults, elderly patients and patients who had received renal transplants had significantly lower lymphoproliferative responses to rotavirus (P = 0.04, P = 0.002, respectively) and phytohaemagglutinin (P = 0.001). However, following acute rotavirus infection, elderly persons mounted good lymphoproliferative and specific antibody responses to rotavirus. No lymphoproliferative response or specific antibody to rotavirus was detected in a child with cartilage hair hypoplasia. In cord blood samples, specific antibodies were detected in the absence of a lymphoproliferative response to rotavirus. Increases in lymphoproliferative responses as well as specific antibodies were not detected in immune adult recipients of a human rotavirus vaccine (RIT 4375), but a recipient of a bovine vaccine (RIT 4237) had an increase in lymphoproliferative response to rotavirus between 13 and 28 days postvaccination. Stimulation indices for both rotavirus and phytohaemagglutinin within the vaccine groups were comparable to the healthy laboratory personnel group.

Human infection with herpes zoster: etiology, pathophysiology, diagnosis, clinical course, and treatment

Herpes zoster is a cutaneous vesicular eruption resulting from recrudescence of the chickenpox virus. It is mainly a disease of adults, with a predisposition for the elderly or immunocompromised. Although usually localized, the disease can disseminate to visceral organs. Diagnosis is often made based on the characteristic pattern of the lesion and clinical features. Tzanck smear, viral isolation, seroconversion, antibody titers, and monoclonal antibodies may further aid or confirm the diagnosis. Clinical features of herpes zoster may follow a progression through 3 stages, prodromal, acute, and chronic. The prodromal and acute phases seldom require more than symptomatic management. The chronic pain syndrome, postherpetic neuralgia (PHN), demands a more aggressive approach. Pharmacologic intervention, neuroaugmentation, and/or surgery may prevent or alleviate PHN, but universal response to any of these therapeutic approaches is unlikely. Tricyclic antidepressants remain the first choice in treating this pain syndrome. A trial of antiviral therapy may be warranted in patients with disseminated disease or in immunocompromised patients with localized disease. Of the antiviral agents, acyclovir is considered the drug of choice by most clinicians.

Effect of age on viral infections: possible role of interferon

In both experimental animals and humans, three stages of susceptibility to viral infections are apparent: 1) the neonatal state, characterized by enhanced susceptibility to infections; 2) childhood and adolescence, during which there is decreased susceptibility; and 3) adulthood (sexual maturity), characterized by increased susceptibility to primary viral infections with advancing age. Moreover, advanced age is associated with reactivation of latent viruses, most notably VZV, and, most likely, oncogenic viruses as well. The mechanisms responsible for these alterations in susceptibility to viral infections have not been completely elucidated. Differences in antibody production do not seem to play a role. Most authors feel that depression of cell-mediated immunity, as measured by delayed cutaneous hypersensitivity or lymphocyte stimulation by mitogens and antigens may be of importance. There have been, however, only few studies on the role of antiviral moieties, such as the interferon(s). Our data on interferon formation in response to coxsackievirus B3 infection in mice suggest that adult mice produce relatively less interferon in relation to the amount of virus replicated in their tissues than do younger animals. Furthermore, the absolute amount of interferon produced by adult animals in response to intravenous injection of (non-replicating virus) NDV was less than that found in younger mice. We report our studies on interferon with no implication that these data supply an adequate explanation for the greater vulnerability of adult mice infected with coxsackievirus B3. It is unlikely that the matter of age and susceptibility has interferon (or indeed any other factor) as a single determinant.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute herpetic and postherpetic neuralgia: clinical review and current management

The pain of acute herpes zoster (HZ) may be severe, but it is usually transitory. A minority of patients, with the elderly at particular risk, go on to develop persistent, severe, often disabling pain called postherpetic neuralgia. Though the clinical features of these conditions are well known, the pathology of PHN is poorly described and the pathogenesis of the pain in both remains conjectural. During the past 60 years, an extraordinary number of pharmacological, anesthetic, and surgical therapies have been applied in an attempt to ameliorate the symptoms of acute herpes zoster, enhance its healing, prevent its transition to postherpetic neuralgia, and treat the pain of those with this complication. Relatively few treatments have been studied in a controlled manner, and fully reliable, safe, and effective therapeutic approaches for preventing and treating postherpetic neuralgia have not yet been found. This review summarizes current information on the epidemiology, clinical features, and pathology of herpes zoster and postherpetic neuralgia, and critically examines the accumulated experience with the various treatments. Guidelines for management are suggested.

Specific lysis of varicella zoster virus-infected B lymphoblasts by human T cells

Epstein-Barr virus-transformed human B cells expressed cell surface varicella-zoster virus (VZV) antigens after superinfection with VZV although they did not form infectious centers in a plaque assay. The VZV-superinfected cells were lysed by autologous VZV-stimulated T-cell lines and their derivative clones. The effector cells were specific for VZV and an HLA DR antigen and were T4+. The specificity of lysis of Epstein-Barr virus-transformed, VZV-superinfected targets by prestimulated mononuclear cells in this system contrasted with the unrestricted lysis seen when the targets were VZV-infected fibroblasts.

Herpes zoster ophthalmicus and granulomatous angiitis. An ill-appreciated cause of stroke

The syndrome of granulomatous angiitis related to varicella zoster virus infection often manifests as herpes zoster ophthalmicus followed by contralateral hemiplegia. Forty-five cases have been reported to date, and the authors' experience with two additional cases seen in a one-year period is described. Given the frequency of both stroke and herpes zoster ophthalmicus in an aging population, the authors postulate that granulomatous angiitis is underdiagnosed. There is need for increased awareness of this disease by the non-neurologist. Diagnostic and therapeutic considerations are reviewed.