Aging and immunity

Bring the life stages into the domain of basic and clinical pharmacology

Completely distinct physiological conditions and immune responses exist among different human life stages. Age is not always consistent with the life stage. We proposed to incorporate the concept of the life stages into basic and clinical pharmacology, including clinical trials, drug labels, and drug usage in clinical practice. Life-stage-based medical treatment is the application of medicine according to life stages such as prepuberty, reproductive, and aging. A large number of diseases are life-stage-dependent. Many medications and therapy have shown various age effects but not been recognized as life-stage-dependent. The same dosage and drug applications used in different life stages lead to divergent outcomes. Incorporating life stages in medicine and drug usage will enhance the efficacy and precision of the medication in disease treatment.

Which National Factors Are Most Influential in the Spread of COVID-19?

The outbreak of the novel COVID-19, declared a global pandemic by WHO, is the most serious public health threat seen in terms of respiratory viruses since the 1918 H1N1 influenza pandemic. It is surprising that the total number of COVID-19 confirmed cases and the number of deaths has varied greatly across countries. Such great variations are caused by age population, health conditions, travel, economy, and environmental factors. Here, we investigated which national factors (life expectancy, aging index, human development index, percentage of malnourished people in the population, extreme poverty, economic ability, health policy, population, age distributions, etc.) influenced the spread of COVID-19 through systematic statistical analysis. First, we employed segmented growth curve models (GCMs) to model the cumulative confirmed cases for 134 countries from 1 January to 31 August 2020 (logistic and Gompertz). Thus, each country's COVID-19 spread pattern was summarized into three growth-curve model parameters. Secondly, we investigated the relationship of selected 31 national factors (from KOSIS and Our World in Data) to these GCM parameters. Our analysis showed that with time, the parameters were influenced by different factors; for example, the parameter related to the maximum number of predicted cumulative confirmed cases was greatly influenced by the total population size, as expected. The other parameter related to the rate of spread of COVID-19 was influenced by aging index, cardiovascular death rate, extreme poverty, median age, percentage of population aged 65 or 70 and older, and so forth. We hope that with their consideration of a country's resources and population dynamics that our results will help in making informed decisions with the most impact against similar infectious diseases.

The effect of sorghum resistance resistant starch-mediated equol on the histological morphology of the uterus and ovaries of postmenopausal rats

Equol is a metabolite of daidzein and has a higher biological activity than daidzein. Equol, combined with estrogen receptors, can reduce the incidence of diseases such as cardiovascular disease, osteoporosis, and breast cancer; more effectively alleviate the symptoms of perimenopausal syndrome; and improve age-related decline of the uterus and ovaries. Research has shown that food composition can greatly affect the formation of equol in the intestinal tract. In the intestines, the content of nonstarch polysaccharides that can stimulate fermentation is high, thereby allowing intestinal bacteria to quickly and completely transform the daidzein into equol. This study used Sprague Dawley (SD) rats as a model, where menopause was established through direct intragastric administration of formistan. In the 6-week-long experiment, intragastric administration of RS while feeding bean pulp reduced the body weight of postmenopausal rats, reduced the efficiency of feed utilization of rats, and increased the weight of organs such as the uterus and ovaries. Routine blood indexes showed that no adverse reactions were produced by intragastric administration of RS. 16s rDNA sequencing further verified Lactobacillus and Clostridium XIVa, as the bacteria that converted daidzein into equol.

Tuberculosis diagnosis: algorithm that May discriminate latent from active tuberculosis

Diagnosis of tuberculosis still faces a lot of challenges and is one of the priorities in the field of tuberculosis management. Deciphering the complex tuberculosis pathogenicity network could provide biomarkers for diagnosis. We discussed the distribution of HLA-B17, -DQB and -DRB together with QuantiFERON test results in tuberculosis infection. A case control study was done during which a total of 337 subjects were enrolled comprising 227 active tuberculosis (ATB), 46 latent tuberculosis infection (LTBI) and 64 healthy controls (HC). Sequence-specific primer polymerase chain reaction and immune epitope database were used to genotype samples and determine the epitope binding ability of the over-represented alleles respectively. QuantiFERON test was done according to manufacturer's instructions. The peptides HLA-B*5801 and HLA-DRB1*12 and the peptides HLA-B*5802 and HLA-DQB1*03 were found to be associated with latent tuberculosis while the haplotypes DRB1*10-DQB1*02 and DRB1*13-DQB1*06 were found to be associated with active tuberculosis (All p-values≤0.05). The association of HLA-B*5801 and HLA-B*5802 with latent tuberculosis was linked to their ability to bind or not mycobacterial antigens. DRB1*10-DQB1*02 haplotype was found to be over-represented in LTBI compared to ATB (p-value = 0.0015) while DRB1*13-DQB1*06 was found to be under-represented in LTBI compared to ATB (p-value = 0.0335). The DRB1*10-DQB1*02 haplotype was only found in the LTBI when compared with the ATB group. The present study suggests the following algorithm to discriminate LTBI from ATB: QuantiFERON+ and DRB1*10-DQB1*02 haplotype + may indicate LTBI; QuantiFERON+ and DRB1*10-DQB1*02 haplotype - may indicate ATB.

Retrospective analysis of older travellers attending a specialist travel health clinic

Background

Older people represent a significant proportion of overseas travellers. The epidemiology of older international travellers is not well described in the literature. This study aims to identify demographics, travel characteristics and the medical profile of older travellers seeking pre-travel health advice in a specialist travel medicine clinic.

Methods

Records of travellers aged 60 years and older attending the Tropical Medical Bureau clinic in Galway, Ireland between 2014 and 2018 were examined. Descriptive and inferential.analysis of data was performed.

Results

A total of 337 older travellers sought pre-travel health advice during the study period. The mean age of the cohort was 65.42 (±10) years. Most of the travellers (n = 267, 80%) had at least one travelling companion. Nearly half of older travellers (n = 155, 46.8%) were travelling with a single companion. Tourism was the main reason for travel for the majority (n = 260, 77.6%), followed by visiting friends and relatives (VFR) (n = 23, 6.9%) travellers. The mean interval remaining before the planned trip was 4.36 (±2) weeks, and the mean duration of travel was 3.16 (±1) weeks. The most popular single country of destination was India with 33 (9.8%) visitors, and South East Asia was the most popular region with 132 (39.2%) older travellers. The majority of travellers (n = 267, 79.2%) had a documented pre-existing medical condition. The most commonly reported medical conditions were hypertension (n = 26, 7.7%), dyslipidaemia (n = 18, 5.3%), diabetes mellitus (n = 12, 3.5%), insect bite sensitivity (n = 11, 3.3%), and hypothyroidism (n = 9, 2.6%). Antihypertensive agents (n = 32, 9.4%) and statins (n = 24, 7.1%) were the most frequently used medications. Typhoid (n = 112, 33.2%) and hepatitis A (n = 84, 24.9%) were the most common vaccinations administered to older travellers at the clinic.

Conclusions

This study provides an insight into the demographics, travel characteristics, and medical profile of elderly travellers seeking advice at a large travel clinic in Ireland. A wide range of travel destinations, diseases and medication use was reported among this group of travellers, which may enable travel medicine physicians to provide more tailored advice and to more appropriately counsel older travellers.

IFN production ability and healthy ageing: mixed model analysis of a 24 year longitudinal study in Japan

OBJECTIVE

To track changes in interferon (IFN) production in healthy individuals to shed light on the effect these changes have on the course of healthy ageing.

DESIGN

Study is based on data that were collected over 24 years from a cohort of individuals whose IFN-α production was quantified as a part of their annual routine health check-up.

SETTING

All individuals in this study underwent regular health check-ups at Louis Pasteur Center for Medical Research.

PARTICIPANTS

295 healthy individuals (159 males and 136 females) without a history of cancer, autoimmune diseases and hepatitis C virus (HCV) whose IFN-α production was quantified more than five times within 24 years were selected. Finally, 29 males and 4 females whose IFN-α production was quantified more than 25 times were selected and their data were analysed using a mixed model.

MAIN OUTCOME MEASURES

HVJ stimulated IFN-α  production was quantified. Healthy individual's periodical log transformed IFN-α values (y) were plotted versus age (x) and fitted to linear (y=mx+n) and quadratic formula (y=ax(2)+bx+c) expressions to reveal changes in the IFN-α  production in these healthy individuals.

RESULTS

The linear expression showed that log (IFN-α) had a slight tendency to decline (3% over 10 years). However, the quadratic formula analysis showed the quadratic expression to be more positive than negative (a concave U-shaped pattern) which means that individuals' once declining IFN production recovered as they aged.

CONCLUSIONS

Although we observed a marginal decline in IFN-α  production, we also observed that IFN production recovered even in individuals in their mid50s to early 60s. These results combined with our previous cross-sectional studies of patients with various diseases suggest that in healthy individuals, the impairment of IFN production is triggered more by the onset of disease (notwithstanding the cause) rather than by ageing.

Adrenal changes associated with adrenarche

The mechanisms causing the rise in adrenal androgen production during the course of adrenarche remain to be defined. However, the increase in steroid release is clearly associated with a series of intra-adrenal changes in the expression of steroidogenic enzymes needed for dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) production, as well as an expansion of the adrenal zona reticularis (ZR). We and others have defined the adrenal expression pattern of key steroidogenic enzymes during adrenarche. As adrenarche proceeds, the expanding ZR expresses greater levels of cytochrome b5 (CYB5) and steroid sulfotransferase (SULT2A1) than the adjacent fasciculata. In contrast, the growing ZR is deficient in 3beta-hydroxysteroid dehydrogenase type 2 (HSD3B2). The resulting profile of steroidogenic enzymes lends itself to the production of adrenal androgens and appears to track the progression of adrenarche. This article reviews the intra-adrenal changes of the adrenal cortex associated with adrenarche.

Advancing age and the risk of nasal carriage of Staphylococcus aureus among patients on long-term hospital-based hemodialysis

BACKGROUND

Elevated nasal carriage rates of Staphylococcus aureus and ensuing complications among the elderly and in those on long-term hemodialysis (HD) are well recognized. The aim of the present study was to determine the extent to which advancing age is associated with the risk of persistent S. aureus nasal carriage among end-stage renal disease (ESRD) patients on long-term HD.

PATIENTS AND METHODS

This prospective study involved 205 ESRD patients enrolled for maintenance HD from July 1997 to July 2000. Persistent nasal carriage was defined by two or more positive cultures for methicillin-susceptible (MSSA) or methicillin-resistant S. aureus (MRSA). Five standardized swabs were taken from the anterior nares of all the patients on long-term HD. S. aureus nasal carriage rates were estimated and compared among ESRD patients of different age groups.

RESULTS

Overall, a prevalence of 38.05% (78/205) for S. aureus nasal carriage was observed, including 27.3% (56/205) for MSSA and 10.7% (22/205) for MRSA. Patients aged 75 to 84 years had the highest (84.6%, 11/13) prevalence of S. aureus nasal carriage (RR, 7.000, 95% CI, 4.350-11.763, P<0.00001). Those aged 65 to 74 years had the next highest (49.0%, 25/51) nasal carriage rates (RR, 4.083, 95% CI, 2.302-7.658, P<0.0001) while patients aged 15 to 24 years (reference group) had the lowest (12.8%, 1/8) prevalence of nasal carriage. The 75 to 84 year age group also had the highest rates of MSSA (46.2%, 6/13), (RR- 3.833, 95% CI, 2.144-7.234, P<0.0001) and MRSA (38.5 %, 5/13) (RR, 6.333, 95%CI, 2.767-16.198, P<0.0001) nasal carriage compared to the reference group.

CONCLUSIONS

Significantly higher persistent MSSA and MRSA nasal carriage rates among ESRD patients >75 years of age are suggestive of an elevated risk of potentially serious S. aureus- related complications among the very elderly during long-term HD. These findings might be helpful in the identification of elderly HD patients as a high-risk group for S. aureus-linked vascular access-related septicemia (VRS) and to evolve appropriate preventive strategies.

Immunosuppression in elderly renal transplant recipients: are current regimens too aggressive?

Renal transplantation is an accepted and successful treatment modality in elderly patients with end-stage renal disease. In comparison with maintenance dialysis, transplantation has been shown to confer a mortality benefit as well as improvements in quality of life in older individuals with end-stage renal disease. Despite this, overall outcomes of renal transplantation in elderly individuals have, in general, been less successful than those of younger renal transplant recipients. Largely, this has been due to the particular vulnerability of elderly patients to the immunosuppressive medications used in renal transplantation. This review article covers these issues in some detail and briefly discusses some of the pharmacokinetic, pharmacodynamic, physiological and immunological differences between younger and older transplant recipients. Elderly renal transplant recipients have both a higher rate of patient death and allograft loss censored for death. Upon multivariate analysis, age of the recipient is strongly associated with allograft loss independent of other known factors. Acute rejections are less frequent in older individuals; however the consequence of a rejection if it occurs is negative for long-term graft survival. On the other hand, death by infection is vastly increased in older versus younger renal transplant recipients. In general, the pharmacokinetics of the immunosuppressive agents are little affected by age, but the tolerance to these agents seems to decrease with increasing age. Elderly renal transplant recipients present a very difficult clinical challenge. As the elderly become an ever-increasing segment of the renal transplant population, new and innovative immunosuppressive strategies will have to be considered and applied.

Impairment of signal transduction in T cells from old mice

T cells from old mice showed impaired proliferative response to antigenic stimulation. To understand the mechanism underlying the age-related impairment of T cell functions, the signal transduction pathway was examined and compared between T cells from young and old mice, and between T cell clones established from a young and old mouse. The age-related changes in T cells were as follows: (1) reduction in the expression and the activation of protein tyrosine kinases associated with T cell receptor (TCR) after antigenic stimulation; (2) reduced phosphorylation of phospholipase C gamma 1 (PLC gamma 1); (3) reduced production of second messengers such as inositoltrisphosphate (IP3) and diacylglycerol (DAG); and (4) reduced influx of Ca2+ ion. Thus, a T cell clone established from an old mouse showed impaired proliferation by stimulation with anti-CD3 antibody, but was fully activated to the level of a T cell clone from a young mouse by stimulation with phorbol acetate myristate (PMA) plus ionomycin (INM). However, splenic T cells freshly prepared from old mice did not show full recovery by the same treatment. The results indicate that one major blockade in the signal transduction of T cells from old mice is present in the pathway just after TCR, but besides this, the blockade is also present in multiple sites down-stream, which can not be bypassed by stimulation with PMA plus INM.