The immune system in the elderly: I. Specific humoral immunity

Immunosenescence and multiple sclerosis: inflammaging for prognosis and therapeutic consideration

Aging is associated with a progressive decline of innate and adaptive immune responses, called immunosenescence. This phenomenon links to different multiple sclerosis (MS) disease courses among different age groups. While clinical relapse and active demyelination are mainly related to the altered adaptive immunity, including invasion of T- and B-lymphocytes, impairment of innate immune cell (e.g., microglia, astrocyte) function is the main contributor to disability progression and neurodegeneration. Most patients with MS manifest the relapsing-remitting phenotype at a younger age, while progressive phenotypes are mainly seen in older patients. Current disease-modifying therapies (DMTs) primarily targeting adaptive immunity are less efficacious in older patients, suggesting that immunosenescence plays a role in treatment response. This review summarizes the recent immune mechanistic studies regarding immunosenescence in patients with MS and discusses the clinical implications of these findings.

Role of sleep deprivation in immune-related disease risk and outcomes

Modern societies are experiencing an increasing trend of reduced sleep duration, with nocturnal sleeping time below the recommended ranges for health. Epidemiological and laboratory studies have demonstrated detrimental effects of sleep deprivation on health. Sleep exerts an immune-supportive function, promoting host defense against infection and inflammatory insults. Sleep deprivation has been associated with alterations of innate and adaptive immune parameters, leading to a chronic inflammatory state and an increased risk for infectious/inflammatory pathologies, including cardiometabolic, neoplastic, autoimmune and neurodegenerative diseases. Here, we review recent advancements on the immune responses to sleep deprivation as evidenced by experimental and epidemiological studies, the pathophysiology, and the role for the sleep deprivation-induced immune changes in increasing the risk for chronic diseases. Gaps in knowledge and methodological pitfalls still remain. Further understanding of the causal relationship between sleep deprivation and immune deregulation would help to identify individuals at risk for disease and to prevent adverse health outcomes.

Immunity and longevity

The role of immune system is to protect the organism from the not built-in program-like alterations inside and against the agents penetrating from outside (bacteria, viruses, and protozoa). These functions were developed and formed during the evolution. Considering these functions, the immune system promotes the lengthening of lifespan and helps longevity. However, some immune functions have been conveyed by men to medical tools (e.g., pharmaceuticals, antibiotics, and prevention), especially in our modern age, which help the struggle against microbes, but evolutionarily weaken the immune system. Aging is a gradual slow attrition by autoimmunity, directed by the thymus and regulated by the central nervous system and pineal gland. Considering this, thymus could be a pacemaker of aging. The remodeling of the immune system, which can be observed in elderly people and centenarians, is probably not a cause of aging, but a consequence of it, which helps to suit immunity to the requirements. Oxidative stress also helps the attrition of the immune cells and antioxidants help to prolong lifespan. There are gender differences in the aging of the immune system as well as in the longevity. There is an advantage for women in both cases. This can be explained by hormonal differences (estrogens positively influences both processes); however, social factors are also not excluded. The endocrine disruptor chemicals act similar to estrogens, like stimulating or suppressing immunity and provoking autoimmunity; however, their role in longevity is controversial. There are some drugs (rapamycin, metformin, and selegiline) and antioxidants (as vitamins C and E) that prolong lifespan and also improve immunity. It is difficult to declare that longevity is exclusively dependent on the state of the immune system; however, there is a parallelism between the state of immune system and lifespan. It seems likely that there is not a real decline of immunity during aging, but there is a remodeling of the system according to the claims of senescence. This is manifested in the remaining (sometimes stronger) function of memory cells in contrast to the production and number of the new antigen-reactive naive T-cells.

Age-related changes in the transcriptome of antibody-secreting cells

We analyzed age-related defects in B cell populations from young and aged mice. Microarray analysis of bone marrow resident antibody secreting cells (ASCs) showed significant changes upon aging, affecting multiple genes, pathways and functions including those that play a role in immune regulation, humoral immune responses, chromatin structure and assembly, cell metabolism and the endoplasmic reticulum (ER) stress response. Further analysis showed upon aging defects in energy production through glucose catabolism with reduced oxidative phosphorylation. In addition aged B cells had increased levels of reactive oxygen-species (ROS), which was linked to enhanced expression of the co-inhibitor programmed cell death (PD)-1.

Update on the use of immunoglobulin in human disease: A review of evidence

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Comparison of serological methods with PCR-based methods for the diagnosis of community-acquired pneumonia caused by atypical bacteria

Background

The diagnosis of community-acquired pneumonia (CAP) caused by Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae is traditionally based on cultures and serology, which have special requirements, are time-consuming, and offer delayed results that limit their clinical usefulness of these techniques. We sought to develop a multiplex PCR (mPCR) method to diagnosis these bacterial infections in CAP patients and to compare the diagnostic yields obtained from mPCR of nasopharyngeal aspirates (NPAs), nasopharyngeal swabs (NPSs), and induced sputum (IS) with those obtained with specifc PCR commercial kits, paired serology, and urinary antigen.

Results

A total of 225 persons were included. Of these, 10 patients showed serological evidence of L. pneumophila infection, 30 of M. pneumoniae, and 18 of C. pneumoniae; 20 individuals showed no CAP. The sensitivities were mPCR-NPS = 23.1 %, mPCR-IS = 57.1 %, Seeplex®-IS = 52.4 %, and Speed-oligo®-NPA/NPS = 11.1 %, and the specificities were mPCR-NPS = 97.1 %, mPCR-IS = 77.8 %, Seeplex®-IS = 92.6 %, and Speed-oligo®-NPA/NPS = 96.1 %. The concordance between tests was poor (kappa <0.4), except for the concordance between mPCR and the commercial kit in IS (0.67). In individuals with no evidence of CAP, positive reactions were observed in paired serology and in all PCRs.

Conclusions

All PCRs had good specificity but low sensitivity in nasopharyngeal samples. The sensitivity of mPCR and Seeplex® in IS was approximately 60 %; thus, better diagnostic techniques for these three bacteria are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12952-016-0047-y) contains supplementary material, which is available to authorized users.

A sustained high fat diet for two years decreases IgM and IL-1 beta in ageing Wistar rats

Background

The immune system undergoes several alterations of innate and adaptive immunity during ageing. The main features of the aged immune system are a reduced diversity of T cell receptors and a reduced activity of innate immune cells with subsequent changes in adaptive immunity resulting in a less effective, less specific, and dys-regulated immune response and in an increased susceptibility towards infection, malignancy, and autoimmunity. The process is referred to as immunosenescence and is also modulated by environmental modifiers, such as dietary factors. High fat diet (HFD), via direct modulation of immune cell function by fatty acids and/or increased body fat mass, influences immune function. However, it is not clear whether HFD is beneficial or detrimental for the functioning of the ageing immune system.

Methods

Male Wistar rats fed with either a high fat diet (HFD 43 en% of fat) or control diet (SD, 25 en% of fat) over up to 24 month and were analyzed for plasma IL-1β, IL-6, TNF, IgM, IgG1, IgA, IgG2a, IgG2b, IgG2c, light chains lambda and kappa, testosterone, prolactin and percentage of splenic B cells and apoptosis rate, respectively.

Results

In general, all analyzed immunoglobuline isotypes increased with age, except for IgA. This increase was attenuated by HFD. In HFD and SD rats the percentage of B cells in the spleen and also their apoptotic rate was lower in aged as compared to young animals with no additional diet-induced effect. Testosterone and prolactin levels were lower in old animals, as expected. There was a statistical trend towards an increased prolactin/testosterone ratio in middle aged (6–12 monthsnth) HFD rats as compared to SD. IL-6 was neither affected by HFD nor age. On the other hand, HFD rats showed a decrease in IL-1β as compared to SD, which correlated with the above-mentioned suppressive effect on immunoglobulin isotypes, especially IgM.

Conclusion

In Wistar rats, HFD reveals an immunosuppressive effect in ageing animals by decreasing immunoglobulins, especially IgM, and IL-1β when compared to SD.

A high density of tertiary lymphoid structure B cells in lung tumors is associated with increased CD4+ T cell receptor repertoire clonality

T and B cell receptor (TCR and BCR, respectively) Vβ or immunoglobulin heavy chain complementarity-determining region 3 sequencing allows monitoring of repertoire changes through recognition, clonal expansion, affinity maturation, and T or B cell activation in response to antigen. TCR and BCR repertoire analysis can advance understanding of antitumor immune responses in the tumor microenvironment. TCR and BCR repertoires of sorted CD4⁺, CD8⁺ or CD19⁺ cells in tumor, non-tumoral distant tissue (NT), and peripheral compartments (blood/draining lymph node [P]) from 47 non-small cell lung cancer (NSCLC) patients (age_median = 68 y) were sequenced. The clonotype spectra were assessed among different tissues and correlated with clinical and immunological parameters. In all tissues, CD4⁺ and CD8⁺ TCR repertoires had greater clonality relative to CD19⁺ BCR. CD4⁺ T cells exhibited greater clonality in NT compared to tumor (p = 0.002) and P (p < 0.001), concentrated among older patients (age > 68). Younger patients exhibited greater CD4⁺ T cell diversity in P compared to older patients (p = 0.05), and greater CD4⁺ T cell clonality in tumor relative to P (p < 0.001), with fewer shared clonotypes between tumor and P than older patients (p = 0.04). More interestingly, greater CD4⁺ and CD8⁺ T cell clonality in tumor and P, respectively (both p = 0.05), correlated with high density of tumor-associated tertiary lymphoid structure (TLS) B cells, a biomarker of higher overall survival in NSCLC. Results indicate distinct adaptive immune responses in NSCLC, where peripheral T cell diversity is modulated by age, and tumor T cell clonal expansion is favored by the presence of TLSs in the tumor microenvironment.

CCL2, CXCL8, CXCL9 and CXCL10 serum levels increase with age but are not altered by treatment with hydroxychloroquine in patients with osteoarthritis of the knees

AIM

Osteoarthritis (OA) is a major cause of morbidity and incapacity in the elderly. This study evaluates serum levels of the chemokines CCL2, CXCL8, CXCL9, and CXCL10 in 16 patients with primary OA of the knees, and investigates how treatment with hydroxychloroquine (HCQ) for 4 months affects these chemokine levels.

METHOD

Thirteen elderly patients received a placebo. Healthy control groups consisted of 10 elderly individuals (age > 60 years) with no clinical or radiological evidence of OA (CT-O), and 10 young adult individuals, (CT-Y group, age < 40 years).

RESULTS

The CT-Y group presented lower levels of all chemokines studied, in comparison to the other groups. HCQ treatment did not alter the serum levels of CCL2 (P = 0.80), CXCL8 (P = 0.76), CXCL9 (P = 0.95) and CXCL10 (P = 0.74) in OA patients.

CONCLUSION

Hydroxychloroquine treatment did not alter the serum levels of CCL2, CXCL8, CXCL9 or CXCL10 in patients with OA of the knees, although increased serum levels correlated with aging for all subjects, including controls.

Persistence of immunity in healthy adults aged ≥ 50 years primed with a hepatitis B vaccine 3 years previously

Hepatitis B vaccines do not generate protective immune responses in older adults as effectively as they do in children and young adults. Improved formulations of existing vaccines may have the potential to improve this. This study investigated the persistence of serum antibodies against hepatitis B surface antigens (anti-HBs) 3.1-3.5 years following primary vaccination with 3 doses of HBvaxPRO® or Engerix B™ in healthy adults aged ≥ 50 years who were further challenged with 1 dose of recombinant hepatitis B antigen. This was an open-label extension study. Individuals (N = 204) with a mean (standard deviation) age at enrollment of 63.7 (7.0) years receiving HBvaxPRO® or Engerix B™ in a randomized, double-blind primary study were challenged with 1 dose of HBvaxPRO® (10 μg). Anti-HBs were measured pre- and 30 days post-challenge. 45.5% (34.8, 56.4 [95% CI]) of individuals who received HBvaxPRO® in the per protocol set (PPS) had anti-HBs titers ≥ 10 mIU/mL pre-challenge and 85.2% (76.1, 91.9) 1-month post-challenge. In those who received Engerix B™ in the primary vaccination series, the results were 58.8% (48.6, 68.5) and 88.3% (80.5, 93.8), respectively. The challenge dose of HBvaxPRO® was generally well tolerated. Subjects aged ≥ 50 years receiving a challenge dose of HBvaxPRO® demonstrated immune memory against hepatitis B 3 years after a 3-dose primary. The safety profile of this challenge dose of HBvaxPRO® was consistent with the well-established safety profile of the vaccine HBvaxPRO®.

Influence of hyperoxia and mechanical ventilation in lung inflammation and diaphragm function in aged versus adult rats

Although assist ventilation with FIO2 0.21 is the preferable mode of ventilation in the intensive care unit, sometimes controlled ventilation with hyperoxia is needed. But the impact of this setting has not been extensively studied in elderly subjects. We hypothesized that a high fraction of inspired oxygen (FiO(2)) and controlled mechanical ventilation (CMV) is associated with greater deleterious effects in old compared to adult subjects. Adult and old rats were submitted to CMV with low tidal volume (6 ml/kg) and FiO(2) 1 during 3 or 6 h. Arterial blood gas samples were measured at 0, 60 and 180 min (four groups: old and adult rats, 3 or 6 h of CMV), and additionally at 360 min (two groups: old and adult rats, 6 h of CMV). Furthermore, total protein content (TPC) and tumor necrosis factor-alpha (TNF-α) in bronchoalveolar lavage were assessed; lung tissue was used for malondialdehyde and histological analyses, and the diaphragm for measurement of contractile function. Arterial blood gas analysis showed an initial (60 min) greater PaO(2) in elderly versus adult animals; after that time, elderly animals had lowers pH and PaO(2), and greater PaCO(2). After 3 h of CMV, TPC and TNF-α levels were higher in the old compared with the adult group (P < 0.05). After 6 h of MV, malondialdehyde was significantly higher in elderly compared with the adult animals (P < 0.05). Histological analysis showed leukocyte infiltration and edema, greater in old animals. In diaphragm, twitch contraction with caffeine significantly declined after 6 h of CMV only for the elderly group. These data support the hypothesis that relatively short-term CMV with low tidal volume and hyperoxia has greatest impact in elderly rats, decreasing diaphragmatic contractile function and increasing lung inflammation.

Does aging affect the immune status? A comparative analysis in 300 healthy volunteers from France, Austria and Spain

Background

As the European population is getting older, there is growing need in scientific data on how to achieve healthy and successful aging. A decline in immune function with age is unanimously supported by many epidemiological and clinical observations, with a decrease in T-cell mediated function encompassing a large part of this alteration. In the EU-funded VITAGE project, the effects of aging on biomarkers of immune status are being studied in three European countries. According to strict inclusion/exclusion criteria, a cohort of 300 healthy male non-smoking 20–75 years old volunteers were enrolled in France (n = 99), Spain (n = 100) and Austria (n = 101). In each country, the volunteers were classified as a function of age (one age group per decade). Biomarkers of immune status were determined including delayed-type hypersensitivity tests, measurement of lymphocyte surface markers, and serum determinations of interleukin-2, complement fractions and immunoglobulins.

Results

There were moderate differences in the biomarkers of immune status of the VITAGE study volunteers among the three European centres. The percentage of Natural Killer (NK) cells was 156% and 142% higher in Spain as compared to France and Austria, respectively (p < 0.0001), and this increase was observed at any age group above 30 years. Comparison between age-groups showed that in Spain, but not in France or Austria, older individuals had significantly a lower B lymphocyte distribution and conversely, a higher NK cell distribution. Moreover, the CD4/CD8 ratio was positively correlated with age in Austrian subjects (p < 0.0001).

Conclusion

Our results provide evidence of an increased NK cell distribution in the elderly, especially in the Spanish population. NK cell status may predict morbidity and mortality in the elderly, emphasizing the importance of innate as well as adaptive immunity in ensuring healthy longevity and cancer resistance, possibly in link with the Mediterranean diet.

Altered molecular repertoire of immune system by renal dysfunction in the elderly: is prediction and targeted prevention in the horizon?

Background

Patients on chronic hemodialysis (HD) have impaired cellular and humoral immunity. The percentage of elderly people among the total population in Taiwan is increasing dramatically, and HD is the primary alternative for renal replacement therapy when renal function declines. Activated vitamin D is widely used in HD patients with secondary hyperparathyroidism (SHPT) and is a well-known immunomodulatory agent. Personalized medicine and integrative medical approach has been a trend in current clinical practice. Can we improve their immune function using vitamin D in spite of the mineral aspect? Here, we investigated the relationship between serum 25-hydroxyvitamin D (25(OH)D) level and T cell differentiation in chronic HD patients.

Methods

Forty patients with chronic HD were enrolled. HD patients with SHPT had been treated with activated vitamin D for 3 months. Peripheral blood mononuclear cells obtained from the patients were cultured and stimulated by mitogens, and T cells were analyzed by flow cytometry. Serum 25(OH)D levels were detected by enzyme-linked immunosorbent assay.

Results

The incidence of T cell differentiation to the T helper cell (Th)2 subtype was more prevalent in the elderly group than in the controls (p = 0.001). Th2 differentiation was also correlated with age (p = 0.004) and serum 25(OH)D levels (p < 0.05). After treated with activated vitamin D, the level of Th1 cytokines decreased while the Th2 cytokine level increased in the sera (p < 0.05). The T cell differentiation tended toward the Th2 subtype (p = 0.027) after treatment of activated vitamin D in SHPT patients.

Conclusions

These results demonstrated that Th2 differentiation is correlated with age and the serum 25(OH)D level of patients. Treatment with activated vitamin D influenced T cell differentiation and cytokine expression in SHPT patients. Taking vitamin D is the possible prediction and targeted treatment in the immune dysfunction in chronic HD patients.

Classical Hodgkin lymphoma, lymphocyte depleted type: clinicopathological analysis and prognostic comparison with other types of classical Hodgkin lymphoma

The lymphocyte-depleted type (LD) is a morphological subtype of classical Hodgkin lymphoma (CHL), but its rarity and heterogeneous morphological character makes a definite clinicopathological identification difficult. To characterize this disease, LD cases were compared with other types of CHL. From 1982 to 2006, we collected 310 CHL cases. Among them, 29 cases were diagnosed as LD. We could additionally analyze clinical data of 157 CHL cases (including 28 LD cases) and the immunophenotype of 150 CHL cases (including 28 LD cases). We compared clinicopathological data between LD cases and other types of CHL cases and determined prognostic factors by univariate and multivariate analysis. LD showed a more progressive disease stage (stage 3/4, 64%) than other types of CHL (stage 3/4, 30%; P<0.001), more frequent B symptoms (89% vs. 40%; P<0.001) and extranodal invasion (50% vs. 11%; P<0.001), older age (median: 66 vs. 33; P<0.001), higher serum soluble interleukin 2 receptor levels (median: 8240U/ml vs. 1705U/ml; P<0.001), and much poorer prognosis regardless of the international prognostic score (IPS) (five-year overall survival: 29% vs. 86%; P<0.001). The morphological subtype of LD represented an independent prognostic factor as did age and IPS by multivariate analysis. Immunohistochemistry showed that the characteristics of Hodgkin and Reed-Sternberg (HRS) cells of LD are basically not different from those of other types of CHL in terms of CD30, CD15, and chemokine receptors, except for high-level EB-virus infection (72% vs. 41%; P=0.002). LD should be distinguished from other types of classical Hodgkin lymphoma because of its definitive clinicopathological characters.

Immune status is more affected by age than by carotenoid depletion-repletion in healthy human subjects

Prospective studies have indicated an age-related impairment of the immune response. Carotenoids have been hypothesised to enhance immune cell function. The aim of the present study was to describe the age-related effects and the impact of in vivo dietary carotenoid depletion and repletion on specific and non-specific immunity. A total of ninety-eight healthy male subjects (aged 20-75 years) received a carotenoid-depleted diet for 3 weeks and were then supplemented daily for 5 weeks with 30 mg β-carotene, 15 mg lycopene and 9 mg lutein. Blood samples were collected at study entry, after depletion and supplementation, and biomarkers of immune status were determined. We found that serum IgA levels were positively correlated with ageing. Lymphocyte phenotyping indicated an increase with age in the memory T-helper cell subpopulation (CD4⁺CD45RO⁺) concomitantly with a decrease in naive T-helper cells (CD4⁺CD45RA⁺). A significant increase in the natural killer cells subpopulation and a small decrease in B lymphocytes were also observed, especially for the oldest volunteers. From ex vivo cell function exploration, a positive correlation was observed between age and IL-2 production of phytohaemagglutinin-stimulated lymphocytes. Neutrophils' bactericidal activity was significantly impaired with age (from 50 years) and was modulated by carotenoid status. An age effect was found on neutrophils' spontaneous migration but not on directed migration. Immune response in healthy human subjects is mostly affected by age rather than by dietary carotenoid depletion and repletion. Even in carefully selected healthy volunteers, some age-related immune changes occur predominantly from 50 years onwards. This immunosenescence could generate a loss in the immune system adjustment capacity.

Superior immunogenicity of seasonal influenza vaccines containing full dose of MF59 (®) adjuvant: results from a dose-finding clinical trial in older adults

BACKGROUND

MF59-adjuvanted influenza vaccines have superior immunogenicity in older adults compared with non-adjuvanted vaccines. We assessed whether changing formulation (i.e., increasing H3N2 antigen or decreasing the quantity of adjuvant) of the licensed, MF59-adjuvanted trivalent influenza subunit vaccine Fluad (®) (Novartis Vaccines and Diagnostics) improves the risk-benefit profile in vaccinees aged ≥ 65 years.

RESULTS

A significant dose-response relationship was observed between antibody levels and MF59 dose; full dose formulations elicited the strongest immune responses, meeting immunogenicity licensure criteria by Day 8. Doubling H3N2 antigen content did not increase the response to this antigen. Increased frequency of circulating CD4+ T-cells specific for vaccine antigens were detected by Day 8; magnitude and functional profile of the CD4+ T-cell response was comparable across the different vaccination groups. Mild to moderate solicited local reactions were more common with vaccines formulated with higher doses of MF59 (®) , but there were no MF59- or antigen dose-related increase in the frequency of solicited systemic reactions or unsolicited adverse events and serious adverse events.

METHODS

We report on 357 subjects who received one of eight intramuscular vaccine formulations. Hemagglutination-inhibiting antibodies were assayed on Days 1, 8 and 22; magnitude and functional profile of CD4+ T-cell responses to vaccine antigens were assessed in subsets. Solicited adverse reactions were reported via diary cards for seven days after vaccination and spontaneous adverse events were monitored throughout the study.

CONCLUSION

This study confirms that the current formulation is the optimal one for MF59-adjuvanted influenza vaccine for use in older adults.

Effect of age and frequency of injections on immune response to hepatitis B vaccination in drug users

Despite the high immunogenicity of the hepatitis B vaccine, evidence suggests that immunological response in drug users is impaired compared to the general population. A sample of not-in-treatment adult drug users from two communities in Houston, TX, USA, susceptible to hepatitis B virus (HBV), was sampled via outreach workers and referral methodology. Participants were randomized to either the standard multi-dose hepatitis B vaccine schedule (0, 1, and 6 months) or to an accelerated (0, 1, and 2 months) schedule. The participants were followed for 1 year. Antibody levels were measured at 2, 6 and 12 months after enrollment in order to determine the immune responses. At 12 months, cumulative adequate protective response was achieved in 65% of the HBV susceptible subgroup using both the standard and accelerated schedules. The standard group had a higher mean antibody titer (184.6 mIU/mL vs 57.6 mIU/mL). But at 6 months, seroconversion at the adequate protective response was reached by a higher proportion of participants and the mean antibody titer was also higher in the accelerated schedule group (104.8 mIU/mL vs. 64.3 mIU/mL). Multivariate analyses indicated a 63% increased risk of non-response for participants 40 years or older (p=0.046). Injecting drugs more than once a day was also highly associated with the risk of non-response (p=0.016). Conclusions from this research will guide the development of future vaccination programs that anticipate other prevalent chronic conditions, susceptibilities, and risk-taking behaviors of hard-to-reach populations.

Non-melanoma skin cancers in elderly patients

Non-melanoma skin cancers are a common reality worldwide. The principal cause that determines the occurrence of these diseases is the exposition of the sun, which principally causes an alteration in the immune system. Therefore, it is possible that other forms of innate or acquired alterations of the immune system could favor the occurrence of non-melanoma skin cancers. For example, several studies have demonstrated that immunosenescence creates an immunosuppressive state that encourages the development of malignances, and new discoveries have noted the importance of T cells and in particular of T regulatory cells (Treg) and T receptor CD28 in this mechanism. Similar results are obtained analyzing the effect of immunosuppressive drugs. The importance of the immune system and its alteration in the genesis of non-melanoma skin cancers is fundamental for the creation of a new therapeutic and less invasive approach.

A randomized controlled study of accelerated versus standard hepatitis B vaccination in HIV-positive patients

BACKGROUND

In human immunodeficiency virus (HIV)-infected patients, the immunogenicity of hepatitis B vaccines is impaired. The primary and secondary aims of our study were to investigate the effectiveness and compliance of 2 different vaccination regimen in an HIV-infected population.

METHODS

A noninferiority trial with a 10% response margin was designed. Included were patients ≥ 18 years old, with negative HBsAg/anti-HBc serology, and not previously vaccinated against hepatitis B. Patients were stratified according to CD4(+) cell count: <200, 200-500, >500. Participants received 10 μg HBvaxPRO intramuscularly according to a 0-1-3 week schedule or the standard 0-4-24 week schedule. Anti-HBs levels were measured at week 28, considered protective ≥ 10 IU/L.

RESULTS

Modified intention to treat analysis in 761 patients was performed. Overall response difference was 50%(standard arm) versus 38.7% (accelerated arm) =11.3% (95% confidence interval [CI], [4.3, 18.3]), close to the 10% response margin. In CD4(+) cell count group 200-500 cells/mm(3,) the response difference was 20.8% (95% CI [10.9, 30.7]). However, the response difference in CD4(+)cell count group >500 cells/mm(3) was -1.8% (95% CI [-13.4,+9.7]). Compliance was significantly superior with the accelerated schedule, 91.8% versus 82.7% (P ≤ .001).

CONCLUSION

In HIV-infected patients, compliance with an accelerated hepatitis B vaccination schedule is significantly better. The efficacy of an accelerated schedule proved to be non-inferior in CD4(+) cell count group >500 cells/mm(3).

CLINICAL TRIALS REGISTRATION

CT00230061.

Targeting inhibitory pathways in cancer immunotherapy

The clinical success of adaptive transfer of in vitro expanded antigen-specific CD8(+) T cells isolated from patients' tumors has demonstrated that effector cells of the adaptive immune system can effectively eliminate even large tumor masses. Nevertheless, cancer vaccines that aim to expand such CD8(+) T cells in situ have had remarkably little success in spite of numerous attempts. Recent advances in basic immunology have revealed layers of complexity controlling activation and maintenance of adaptive immune responses that are tightly controlled by immunoinhibitory pathways to avoid horror autotoxicus. During tumor progression the activities of negative pathways increase and together with cancer immune evasion tactics presumably prevent induction of an efficacious immune response by cancer vaccines that solely provide more antigen to an already suppressed system. Cancer vaccines may thus need to readjust the imbalance of the cancer patients' immune system by inhibiting immunoinhibitors; such regimens have shown preclinical efficacy and are now entering clinical trials hopefully ending the Kafkaesque futility of cancer vaccines.

Leukocyte function in the aging immune system

Aging is associated with a progressive dysregulation of immune responses. Whether these changes are solely responsible for the observed increased mortality and morbidity amongst the elderly is uncertain. Recent advances have highlighted the age-associated changes that occur beyond T and B lymphocytes. Additionally, multiple human and animal studies have identified a relationship between chronic low-grade inflammation and geriatric syndromes, such as frailty, suggesting that the phenomenon of "inflamm-aging" may provide a rationale for the increased vulnerability to chronic inflammatory diseases in older adults. In the present review, we broadly summarize our current understanding of age-dependent changes in leukocyte function and their contribution to aging-related disease processes.

Antibacterial agents in the elderly

Older patients disproportionately suffer the burden of infection in the community and in health care facilities. The rational approach to antimicrobial therapy for older patients with infection requires an appreciation and understanding of the complex immunologic, epidemiologic, pharmacologic, and microbiologic factors that influence the manifestations and consequences of infection in this group. Specific recommendations for common infectious syndromes must take into account the unique needs of older patients and should be tailored for each individual case.

Naive CD4 T cells from aged mice show enhanced death upon primary activation

Poor T cell immunity is one of the many defects seen in elderly humans and aged (Ad) mice. We report that naive CD4 T cells from aged mice (ANCD4 cells) showed greater apoptosis upon primary activation than those from young (Yg) mice, with loss of mitochondrial membrane potential, poor activation of Rel family transcription factors and increased DNA damage. Their ability to enhance glycolysis, produce lactate and induce autophagy following activation was also compromised. ANCD4 cells remained susceptible to death beyond first cell division. Activated ANCD4 cells also showed poor transition to a 'central memory' (CM) CD44(high), CD62L(high) phenotype in vitro. This correlated with low proportions of CM cells in Ad mice in vivo. Functionally, too, IFN-gamma responses recalled from T cells of immunized Ad mice, poor to begin with, worsened with time as compared with Yg mice. Thus, ANCD4 cells handle activation-associated stress very poorly due to multiple defects, possibly contributing to poor formation of long-lasting memory.

Assessment of the Potential Role of Tryptophan as the Precursor of Serotonin and Melatonin for the Aged Sleep-wake Cycle and Immune Function: Streptopelia Risoria as a Model

In the present review we summarize the relationship between the amino acid, tryptophan, the neurotransmitter, serotonin, and the indole, melatonin, with the rhythms of sleep/wake and the immune response along with the possible connections between the alterations in these rhythms due to aging and the so-called “serotonin and melatonin deficiency state.” The decrease associated with aging of the brain and circulating levels of serotonin and melatonin seemingly contributes to the alterations of both the sleep/wake cycle and the immune response that typically accompany old age. The supplemental administration of tryptophan, e.g. the inclusion of tryptophan-enriched food in the diet, might help to remediate these age-related alterations due to its capacity of raise the serotonin and melatonin levels in the brain and blood. Herein, we also summarize a set of studies related to the potential role that tryptophan, and its derived product melatonin, may play in the restoration of the aged circadian rhythms of sleep/wake and immune response, taking the ringdove (Streptopeliarisoria) as a suitable model.

The urban elderly in the United States: health status and the environment

A large number of elderly persons live in United States metropolitan areas and center cities. Although the urban environment can be supportive of health, the urban elderly face issues of decrease in organ function and reserves; impaired chemical clearance and detoxification; vulnerability to medication-environment adverse interactions (heat/psychotropic drugs); legacy of past occupational and environmental cumulative exposures to persistent agents; overall poorer health status; decreased ability to respond to disasters, emergencies, and extreme conditions; decreased ability to access good and services outside their homes; and increased sensitivity to environmental conditions. Planning for these challenges can create a supportive environment and improve the health of the urban elderly.

Pandemic influenza vaccines

Since their compositions remain uncertain, universal pandemic vaccines are yet to be created. They would aim to protect globally against pandemic influenza viruses that have not yet evolved. Thus they differ from seasonal vaccines to influenza virus, which are updated annually in spring to incorporate the latest circulating viruses, and are then produced and delivered before the peak influenza season starts in late fall and winter. The efficacy of seasonal vaccines is linked to their ability to induce virus-neutralizing antibodies, which provide subtype-specific protection against influenza A viruses. If pandemic vaccines were designed to resemble current vaccines in terms of composition and mode of action, they would have to be developed, tested, and mass-produced after the onset of a pandemic, once the causative virus had been identified. The logistic problems of generating a pandemic vaccine from scratch, conducting preclinical testing, and producing billions of doses within a few months for global distribution are enormous and may well be insurmountable. Alternatively, the scientific community could step up efforts to generate a universal vaccine against influenza A viruses that provides broadly cross-reactive protection through the induction of antibodies or T cells to conserved regions of the virus.

Conditions that diminish myeloid-derived suppressor cell activities stimulate cross-protective immunity

Immunity conferred by conventional vaccines is restricted to a narrow range of closely related strains, highlighting the unmet medical need for the development of vaccines that elicit protection against multiple pathogenic serotypes. Here we show that a Salmonella bivalent vaccine comprised of strains that lack and overproduce DNA adenine methylase (Dam) conferred cross-protective immunity to salmonella clinical isolates of human and animal origin. Protective immunity directly correlated with increased levels of cross-reactive opsonizing antibodies and memory T cells and a diminished expansion of myeloid-derived suppressor cells (MDSCs) that are responsible for the immune suppression linked to several conditions of host stress, including chronic microbial infections, traumatic insults, and many forms of cancer. Further, aged mice contained increased numbers of MDSCs and were more susceptible to Salmonella infection than young mice, suggesting a role for these cells in the immune declines associated with the natural aging process. These data suggest that interventions capable of reducing MDSC presence and activities may allow corresponding increases in B- and T-cell stimulation and benefit the ability of immunologically diverse populations to be effectively vaccinated as well as reducing the risk of susceptible individuals to infectious disease.

Acquired immunity: immunosenescence and physical activity

Several lines of evidence indicate that infectious diseases, cancer, and autoimmune disorders occur more frequently in elderly people, thus suggesting that altered function of immune organs and cells, such as thymus and T and B lymphocytes are of primary importance in the pathogenesis of these diseases. Furthermore, old subjects are less responsive to vaccine than younger because of immune changes. The most common changes accompanying the adaptive immune system include decrement of T and B cells proliferation, repertoire degeneracy, increase of the memory cell type, decreased numbers of naive cells, and shift from T helper1 (Th1) to T helper2 (Th2) response. Regular exercise in the elderly may improve the alterations in acquired immunity which follow the physiological process of aging, allowing a major resistance against external pathogens and a better quality of life.

Interleukin-6 has differential influence on the ability of adjuvant formulations to potentiate antibody responses to a Plasmodium falciparum blood-stage vaccine

The efficacy of vaccine adjuvants can be influenced by the immunological environment of the host, depending on the mechanism(s) by which they exert their immunopotentiating activities. Interleukin-6 is a pleiotropic cytokine that has a broad range of biological activities on immune and non-immune cells. We investigated the role of IL-6 on the ability of nine adjuvant formulations to induce antibody responses to the Plasmodium falciparum MSP1-19 malaria vaccine, using IL-6-/- (KO) mice. Results showed that some adjuvants, i.e. MPL-SE, CFA/IFA, ISA720/QS21/MPL, depended on IL-6 for their efficacy, while others exhibited increased potency in its absence. The efficacy of adjuvants in the IL-6 KO environment cannot be solely attributed to their ability to stimulate antigen-specific cellular responses, suggesting that other biological activities of IL-6 are also important. The results further suggest that two adjuvants utilized dissimilar pathways to potentiate the same type of immune response.

Hepatitis A/B vaccination of adults over 40 years old: Comparison of three vaccine regimens and effect of influencing factors

Challenged by contrasting data on low immune responses in the elderly with a combined hepatitis A/B vaccine, a randomised, controlled study was conducted to assess the immunogenicity of three hepatitis A and B vaccination regimens (group 1: combined hepatitis A/B vaccine Twinrix [GSK]; group 2: co-administered hepatitis A vaccine, Havrix [GSK]+hepatitis B vaccine Engerix -B [GSK], group 3: co-administered hepatitis A vaccine, Vaqta [Sanofi-Pasteur MSD]+hepatitis B vaccine HB VAX PRO [Sanofi-Pasteur MSD]) and the effect of influencing factors in subjects >40 years. On completion of the full vaccination course, anti-HBs seroprotection (SP) rates were 92, 80 and 71% in groups 1, 2 and 3, respectively; anti-HAV seropositivity (S+) rates were 97, 99 and 99%, respectively. In group 1, anti-HBs SP rate was non-inferior as well as superior and anti-HAV S+ rate was non-inferior to that in groups 2 and 3. Anti-HBs response was most significantly influenced by the vaccine regimen, followed by age, gender and BMI (stepwise multiple regression analysis). BMI had the most significant influence on HAV response followed by age, gender and vaccine regimen. In conclusion, Twinrix induced superior hepatitis B SP rates and similar hepatitis A S+ rates compared to concomitant administration of monovalent vaccines in subjects aged >40 years.

B cells from aged mice exhibit reduced apoptosis upon B-cell antigen receptor stimulation and differential ability to up-regulate survival signals

During ageing, autoimmune disorders and the higher susceptibility to infectious have been associated with alterations in the humoral immune response. We report that splenic B lymphocytes from aged mice exhibit lower level of apoptosis induced by B-cell antigen receptor (BCR) ligation in vitro. Respect to B cells from young mice the anti-mu stimulated aged B cells show similar Bcl-2 and Bcl-xL expression but differential kinetic of A1 degradation and a higher level of cFLIP and FAIM. Even though B cells from aged mice show minor Fas expression they exhibit the same susceptibility to anti-Fas induced apoptosis. Aged B cells also present upon BCR stimulation, a higher proliferative response and similar level of activation markers expression than B cells from young mice. These data agree with the observation that aged mice exhibit an increment of T2 and mature B cell subset which rapidly enters cell cycle upon BCR engagement. The diminished apoptosis after activation in aged mice could compromise homeostatic mechanism allowing the persistence of self and non-self antigen specific B cells.

Age-related alterations to immune parameters in Labrador retriever dogs

In order to assess age-related changes in the immune status of Labrador retriever dogs, leukocyte phenotypes, lymphocyte proliferative capacity, and serum antibody levels were measured in four cohorts of dogs, ranging from 2 to 10 years of age. Absolute numbers of white blood cells, lymphocytes, monocytes, granulocytes, and CD3+, CD4+, CD8+ and CD21+ lymphocytes significantly decreased with increasing age. Relative percentages of lymphocytes and CD4 cells were significantly decreased, and relative percentages of granulocytes and CD8 cells significantly increased, with age. The CD4:CD8 ratio showed a significant age-related decrease. Proliferative responses of T-cells to mitogens in whole-blood cultures either increased (Concanavalin A) or remained the same (phytohemagglutinin) with age when data was normalised to allow for differences in responding cell number. Similarly, normalised data of proliferative response to anti-CD3 stimulation together with phorbol 12-myristate 13-acetate showed an age-related increase. Serum levels of total IgA significantly increased with age whereas total IgG levels remained unchanged. These observations illustrate a significant change to a number of immune parameters with age. However, further work is required to determine whether the differences reported here are sufficient to cause overt or functional immune senescence in Labrador retriever dogs.

Melatonin, immune function and aging

Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness. Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect. Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state.

Age-dependent changes in CXC chemokine ligand 10 serum levels in euthyroid subjects

Circulating levels of cytokines are deeply influenced by aging, and few data about serum chemokines are available. The aim of this study was to evaluate the influence of aging on circulating CXCL10. One hundred forty healthy subjects (70 males and 70 females), 10-79 years of age, underwent fasting plasma glucose, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride, and CXCL8 serum assay. Thyroid hormone testing for thyroid-stimulating hormone (TSH), antithyroglobulin (AbTg), and antithyroperoxidase (AbTPO) autoantibodies and thyroid ultrasonography were performed in all subjects to exclude the presence of clinical or subclinical thyroid disease. Serum CXCL10 levels were assayed in all subjects and found to be increased in 14 of 70 females (20%) and in 4 of 70 males (5.7%) (p = 0.01). In a multiple linear regression model including age, body mass index (BMI), systolic and diastolic blood pressure, glycemia, total cholesterol, HDL, LDL, triglycerides, TSH, AbTPO, AbTg, and CXCL8, only age was significantly related to CXCL10 [C.R. 1.30 (0.28-2.33), p = 0.001]. No relationship was present between CXCL8 serum levels and age, suggesting a specificity of CXCL10 elevation as a function of age. Results of this study, performed in healthy subjects on an age gradient, demonstrate an increase in serum CXCL10 with advancing age overall in females, supporting the hypothesis of enhanced Th1 immune responses in aging.

A possible role for humoral immunity in the pathogenesis of Parkinson's disease

The pathogenesis of idiopathic Parkinson's disease is unknown, but nigral degeneration and depigmentation are associated with microglial inflammation and anti-inflammatory medications appear to protect against the disease. The possibility that humoral immunity may play a role in initiating or regulating the inflammation has been suggested by experimental studies triggering dopamine cell death using a variety of transfer strategies and the observation of CD8+ T lymphocytes and complement in the nigra in Parkinson's disease. We analysed the association between degeneration and humoral immune markers in brain tissue of patients with idiopathic (n = 13) or genetic (n = 2 with alpha-synuclein and n = 1 with parkin mutations) Parkinson's disease and controls without neurological disease (n = 12) to determine the humoral immune involvement in Parkinson's disease. Formalin-fixed tissue samples from the substantia nigra and primary visual cortex for comparison were stained for alpha-synuclein, major histocompatibility complex II (HLA), immunoglobulin M (IgM), immunoglobulin G (IgG), IgG subclasses 1-4 and IgG receptors FcgammaR I-III. Antigen retrieval and both single immunoperoxidase and double immunofluorescence procedures were employed to determine the cell types involved and their pattern and semiquantitative densities. Significant dopamine neuron loss occurred in all patients with Parkinson's disease, negatively correlating with disease duration (r = -0.76, P = 0.002). Although all patients had increased inflammatory HLA immunopositive microglia, the degree of inflammation was similar throughout the disease (r = 0.08, P = 0.82). All patients with Parkinson's disease had IgG binding on dopamine neurons but not IgM binding. Lewy bodies were strongly immunolabelled with IgG. A mean 30 +/- 12% of dopamine nigral neurons were immunoreactive for IgG in Parkinson's disease with the proportion of IgG immunopositive neurons negatively correlating with the degree of cell loss in the substantia nigra (r = -0.67, P < 0.0001) and positively correlating with the number of HLA immunopositive microglia (r = 0.51, P = 0.01). Most neuronal IgG was the IgG1 subclass with some IgG3 and less IgG2 also found in the damaged substantia nigra. The high affinity activating IgG receptor, FcgammaRI, was expressed on nearby activated microglia. The low affinity activating IgG receptor, FcgammaRIII was expressed on cells morphologically resembling lymphocytes, whereas immunoreactivity for the inhibitory IgG receptor FcgammaRII was absent in all cases. This pattern of humoral immune reactivity is consistent with an immune activation of microglia leading to the targeting of dopamine nigral neurons for destruction in both idiopathic and genetic cases of Parkinson's disease.

Effect of a traditional Japanese herbal medicine, hochu-ekki-to (Bu-Zhong-Yi-Qi Tang), on immunity in elderly persons

In general, the elderly show a significant age-related decline in their immune response, thus leading to an increased vulnerability to infections or to an increase in the occurrence of malignant tumors. In this study, we examined the effect of Hochu-ekki-to (HOT or TJ-41) on the immunological capacity of the elderly. A group of elderly patients complaining of general fatigue or weakness were orally administered 7.5 g of HOT everyday for at least 120 days (4 months), whereas another group of aged patients mainly complaining of a loss of appetite were daily given 7.5 g of Anchu-san (TJ-5) during the same period and served as a control group. From the immunological point of view, the total number of circulating leukocytes remained unchanged, during the observation period both in the HOT and Anchu-san groups, as well as the ratios between CD3(+) T and CD20(+) B cells and between CD4(+) T and CD8(+) T cells. In addition, no differences were observed in the expression of CD25 antigen, which represents an activated state of T cells. However, as verified on day 30 as well as on day 120 after the administration of HOT, the natural killer (NK) activity against K562 target cells was significantly enhanced, in comparison to the results on day 0 in the HOT group, as well as to that activity on days 0, 30 and 120 in the Anchu-san group. In addition, on days 30 and 120 in the HOT group, there was a significant increase in the serum IFN-gamma level, which is thought to be associated with the NK activity, whereas no significant changes in that level were observed in the Anchu-san group, during the study period. From these results, it may be concluded that the administration of HOT to elderly people may help them improve, at least to some degree, their immunological capacity.

Meta-analysis: the effect of age on immunological response to hepatitis B vaccine in end-stage renal disease

BACKGROUND

Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non-uraemic population. A variety of inherited or acquired factors have been implicated in this diminished response. Age-associated changes in immune status may contribute to decreased vaccine efficacy in older individuals although contradictory results have been reported in individuals with normal kidney function.

AIMS

To evaluate the relationship between age and immune response to hepatitis B vaccine in patients with end-stage renal disease by performing a systematic review of the literature with a meta-analysis of clinical trials.

METHOD

We used the random effects model of DerSimonian and Laird; sources of heterogeneity in effect estimates were explored by performing sensitivity analyses.

RESULTS

We identified 17 clinical trials (1800 unique patients); six (35%) were controlled studies. Pooling of study results demonstrated a significantly decreased risk of response to hepatitis B vaccine among older dialysis patients (overall risk ratio: 0.74; 95% confidence intervals: 0.70-0.79). The P-value was 0.0139 for our test of study heterogeneity. A lowered risk of response to hepatitis B vaccine persisted after exclusion of trials based on plasma-derived vaccines; it was present even when 'older' individuals were defined as being as 50 years (RR: 0.85, 95% CI: 0.75-0.96) or more (cut-off 60 years RR: 0.75; 95% CI: 0.66-0.85). An effect of age on seroprotection rate was present in all clinical reports, irrespective of the geographic origin of the study group: Europe (RR: 0.76; 95% CI: 0.70-0.83) North America (RR: 0.67; 95% CI: 0.60-0.74) or other countries (RR: 0.83; 95% CI: 0.71-0.97). Additional doses of vaccine did not appear to have an impact on RR of response by age.

CONCLUSIONS

Our meta-analysis showed a clear association between older age and impaired response to hepatitis B virus vaccine in end-stage renal disease patients. Such a relationship is biologically plausible. Vaccination schedules with adapted vaccine doses and frequent serum testing for loss of immunity against hepatitis B virus are recommended in elderly patients on maintenance dialysis.

Melatonin, human aging, and age-related diseases

The worldwide prolongation of the mean life expectancy has resulted in a rapid increase of the size of the elderly population (over the age of 60), both in numbers and as a proportion of the whole. As a consequence, increasing the number of potential beneficiaries of health and pension funds, mainly those aged 65 and over raises many social and economic problems since they are supported by a relatively smaller number of potential contributors, i.e. those in the economically active ages between 18 and 64. Therefore, there is a search for any therapeutic agent improving quality of life in the elderly. A role for melatonin as such a compound was recently suggested. In this survey, data on the possible role of melatonin in human aging and age-related diseases are briefly presented. Undoubtedly the aging process is multi-factorial, and no single factor has been identified which satisfactorily explains the phenomenon. Although many theories relating the pineal gland and its secretory product melatonin to aging have been proposed, the role of this agent in the aging process is still unclear. However, for several reasons it seems reasonable to postulate a role for melatonin in this process. Melatonin levels decline gradually over the life-span and may be related to lowered sleep efficacy, very often associated with advancing age, as well as to deterioration of many circadian rhythms. Melatonin exhibits immunomodulatory properties, and a remodeling of immune system function is an integral part of aging. Finally, because melatonin is a potent free radical scavenger, its deficiency may result in reduced antioxidant protection in the elderly which may have significance not only for aging per se but also may contribute to the incidence or severity of some age-related diseases. Presently available data do not allow us to conclude that melatonin may have a role in extending normal longevity. However, although melatonin cannot be recognized as 'rejuvenating' agent, some of its actions may be beneficial for the aging process. Administration of melatonin may improve temporal organization in advanced age. Moreover, it has beneficial effects on sleep as well as age-related diseases. Although recommendations of melatonin supplementation in elderly should be considered, there is a need for extensive studies on the use of melatonin in order to improve the quality of life in advanced age.

An unusual case of chronic meningitis

BACKGROUND

Chronic meningitis is defined as symptoms and signs of meningeal inflammation and persisting cerebrospinal fluid abnormalities such as elevated protein level and pleocytosis for at least one month.

CASE PRESENTATION

A 62-year-old woman, of unremarkable past medical history, was admitted to hospital for investigation of a four-week history of vomiting, malaise an associated hyponatraemia. She had a low-grade pyrexia with normal inflammatory markers. A CT brain was unremarkable and a contrast MRI brain revealed sub-acute infarction of the right frontal cortex but with no evidence of meningeal enhancement. Due to increasing confusion and patient clinical deterioration a lumbar puncture was performed at 17 days post admission. This revealed gram-negative coccobacilli in the CSF, which was identified as Neisseria meningitidis group B. The patient made a dramatic recovery with high-dose intravenous ceftriaxone antibiotic therapy for meningococcal meningitis.

CONCLUSIONS

1) Chronic bacterial meningitis may present highly atypically, particularly in the older adult. 2) There may be an absent or reduced febrile response, without a rise in inflammatory markers, despite a very unwell patient. 3) Early lumbar puncture is to be encouraged as it is essential to confirm the diagnosis.4) Despite a delayed diagnosis appropriate antibiotic therapy can still lead to a good outcome.

Mycoplasma pneumoniae and its role as a human pathogen

Mycoplasma pneumoniae is a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of morbidity associated with it in both children and adults. Serious infections requiring hospitalization, while rare, occur in both adults and children and may involve multiple organ systems. The severity of disease appears to be related to the degree to which the host immune response reacts to the infection. Extrapulmonary complications involving all of the major organ systems can occur in association with M. pneumoniae infection as a result of direct invasion and/or autoimmune response. The extrapulmonary manifestations are sometimes of greater severity and clinical importance than the primary respiratory infection. Evidence for this organism's contributory role in chronic lung conditions such as asthma is accumulating. Effective management of M. pneumoniae infections can usually be achieved with macrolides, tetracyclines, or fluoroquinolones. As more is learned about the pathogenesis and immune response elicited by M. pneumoniae, improvement in methods for diagnosis and prevention of disease due to this organism may occur.

Increased incidence of pathological and clinical prostate cancer with age: age related alterations of local immune surveillance

PURPOSE

The incidence of prostate cancer dramatically increases with age. The etiology still awaits elucidation, and the question as to why it is so prominently a disease of aging remains unanswered. We offer an explanation by suggesting an age related deficient immune surveillance.

MATERIALS AND METHODS

Reports published in the scientific literature with relevance to cancer and immunity, immune senescence, blood-prostate barrier and immune privilege were identified using MEDLINE.

RESULTS

The existence of a blood-prostate barrier is a fair assumption, and the prostate may be considered an immune privileged site. With aging the prostate, a priori immunologically under surveilled, probably becomes more and more so. There is impaired function, transmigration and probably penetration into the gland of natural killer and other immune competent cells due to the onset of immune senescence coupled with impaired diapedesis and possible age related alterations in the blood-prostate barrier.

CONCLUSIONS

Apparently, with aging the immune surveillance of the already immune privileged prostate is progressively and further affected. This condition may result in the inability of the gland to eradicate emergent malignant cells.

Investigation of KIR diversity in immunosenecence and longevity within the Irish population

Natural killer (NK) cells play a pivotal role in the innate immune response. During the ageing process, variations occur in NK cell number and function. The cytolytic activity of NK cells is controlled by an array of activating and inhibitory cell surface receptors, including the killer cell immunoglobulin-like receptors (KIRs). In the present study, genetic diversity of the KIR loci was analysed with respect to successful ageing in the Irish population. A PCR-SSOP KIR gene identification system was employed to determine the frequency of the named KIR genes/pseudogenes and KIR genotypes within a healthy aged cohort and young control group. Although, two KIR genes (2DS3, 2DL5) displayed an initial increased frequency in the aged group, the significance of this association was lost when repeated in a second cohort. In view of the lack of studies to date, investigating the role of the KIR gene system in healthy ageing, further analysis of KIR diversity is required to fully elucidate it's role in respect to age-related disease and longevity.

Direct Measurement of T Cell Subset Kinetics In Vivo in Elderly Men and Women

The age-associated decline in immunocompetence is paralleled by changes in the proportions of PBL subpopulations. In turn, the size and composition of the peripheral lymphocyte pool is determined by input from the thymus and bone marrow and by the balance of proliferation and death in each lymphocyte subpopulation. We compared the kinetics of lymphocyte subtypes in young (seven of eight CMV seronegative) and healthy elderly human subjects (six of seven CMV seropositive), using deuterated glucose DNA labeling in vivo to measure rates of T cell proliferation and disappearance. For CD45RO(+) cells of both CD4(+) and CD8(+) subtypes and for CD4(+)CD45RA(+) cells the kinetics of proliferation and disappearance were remarkably similar between elderly and young subjects. In the young, the kinetics of CD8(+)CD45RA(+) cells with a naive phenotype resembled those of CD4(+)CD45RA(+) cells. However, CD8(+)CD45RA(+) T cells from the elderly exhibited a predominantly primed phenotype, and for this subset, although the proliferation rate was similar to that of other CD45RA(+) cells, the disappearance rate of labeled cells was greatly decreased compared with that of all other T cell subsets. Our data provide a direct demonstration that there are no substantial changes in in vivo kinetics for most T cell populations in healthy elderly compared with young subjects. However, primed CD8(+)CD45RA(+) cells show unusual kinetic properties, indicating the persistence of these cells in the blood and dissociation of proliferation from disappearance.

Virosomal influenza vaccine: a safe and effective influenza vaccine with high efficacy in elderly and subjects with low pre-vaccination antibody titers

In 14 clinical studies, various efficacy and safety aspects of a new virosomal influenza vaccine (Invivac) were assessed in 2865 subjects. The virosomal influenza vaccine fully complies with the Committee for Proprietary Medicinal Products (CPMP) requirement for immunogenicity of influenza vaccines. In particular, in a subset of subjects with low pre-vaccination titers (thus those persons who actually need protection by a vaccine), between 76 and 99% of subjects (dependent on age, health status and vaccine components) achieved protective hemagglutination inhibiting (HI) antibody titers after vaccination with the virosomal influenza vaccine. Acceptable frequencies of well-known local and systemic reactions were observed in healthy adults and risk subjects in clinical studies and in a post-marketing study population. These reactions were transient and generally not severe, and did not cause major inconvenience. In conclusion, Invivac is an efficacious and safe vaccine for the protection against influenza in healthy and chronically ill adult subjects. The vaccine is especially efficacious in subjects with low pre-vaccination immunity.

Sleep associated regulation of T helper 1/T helper 2 cytokine balance in humans

Recent human studies suggested a supportive influence of regular nocturnal sleep on immune responses to experimental infection (vaccination). We hypothesized here that sleep could ease such responses by shifting the balance between T helper 1 (Th1) and T helper 2 (Th2) cytokine activity towards Th1 dominance thereby favoring cellular over humoral responses to infection. We compared the Th1/Th2 cytokine balance in 14 healthy men during regular nocturnal sleep (between 23:00 and 07:00 h) and while remaining awake during the same nocturnal interval, in a within-subject cross-over design. Blood was collected every 2 h. Production of T cell derived cytokines--interferon-gamma (IFN-gamma), interleukin-2 (IL-2), interleukin-4 (IL-4), and tumor necrosis factor-alpha (TNF-alpha)--was measured at the single cell level using multiparametric flow cytometry. Also, several immunoactive hormones--prolactin, growth hormone (GH), thyroid stimulating hormone (TSH), cortisol, and melatonin--were measured, the release of which is known to be regulated by sleep. Compared with wakefulness, early nocturnal sleep induced a shift in the Th1/Th2 cytokine balance towards increased Th1 activity, as indicated by an increased (p <.05) ratio of IFN-gamma/IL-4 producing T helper cells. However, the Th1 shift was only of moderate size and replaced by Th2 dominance during late sleep (p <.05). It could be mediated via release of prolactin and GH which both were distinctly increased during sleep (p <.001). Though unexpected, the most pronounced effect of sleep on T cell cytokine production was a robust decrease in TNF-alpha producing CD8+ cells probably reflecting increased extravasation of cytotoxic effector and memory T cells.