Senotherapeutics: An emerging approach to the treatment of viral infectious diseases in the elderly

Post-acute sequelae of SARS-CoV-2 infection (Long COVID) in older adults

Long COVID, also known as PASC (post-acute sequelae of SARS-CoV-2), is a complex infection-associated chronic condition affecting tens of millions of people worldwide. Many aspects of this condition are incompletely understood. Among them is how this condition may manifest itself in older adults and how it might impact the older population. Here, we briefly review the current understanding of PASC in the adult population and examine what is known on its features with aging. Finally, we outline the major gaps and areas for research most germane to older adults.

Assessing the Impact of Frailty on Infection Risk in Older Adults: Prospective Observational Cohort Study

Background

Infectious diseases are among the leading causes of death and disability and are recognized as a major cause of health loss globally. At the same time, frailty as a geriatric syndrome is a rapidly growing major public health problem. However, few studies have investigated the incidence and risk of infectious diseases in frail older people. Thus, research on frailty and infectious diseases is urgently needed.

Objective

The purpose of this study was to evaluate the association between frailty and infectious diseases among older adults aged 65 years and older.

Methods

In this prospective observational cohort study, we have analyzed the infectious disease prevalence outcomes of older adults aged 65 years and older who participated in frailty epidemiological surveys from March 1, 2018, to March 2023 in Dalang Town, Dongguan City, and from March 1, 2020, to March 2023 in Guancheng Street, Dongguan City. This study has an annual on-site follow-up. Incidence data for infectious diseases were collected through the Chinese Disease Control and Prevention Information System-Infectious Disease Monitoring and Public Health Emergency Monitoring System. A project-developed frailty assessment scale was used to assess the frailty status of study participants. We compared the incidence rate ratios (IRR) of each disease across frailty status, age, and gender to determine the associations among frailty, gender, age, and infectious diseases. Cox proportional hazards regression was conducted to identify the effect of frailty on the risk of demographic factors and frailty on the risk of infectious diseases, with estimations of the hazard ratio and 95% CI.

Results

A total of 235 cases of 12 infectious diseases were reported during the study period, with an incidence of 906.21/100,000 person-years in the frailty group. In the same age group, the risk of infection was higher in men than women. Frail older adults had a hazard ratio for infectious diseases of 1.50 (95% CI 1.14-1.97) compared with healthy older adults. We obtained the same result after sensitivity analyses. For respiratory tract-transmitted diseases (IRR 1.97, 95% CI 1.44-2.71) and gastrointestinal tract-transmitted diseases (IRR 3.67, 95% CI 1.39-10.74), frail older adults are at risk. Whereas no significant association was found for blood-borne, sexually transmitted, and contact-transmitted diseases (IRR 0.76, 95% CI 0.37-1.45).

Conclusions

Our study provides additional evidence that frailty components are significantly associated with infectious diseases. Health care professionals must pay more attention to frailty in infectious disease prevention and control.

Loss of CFTR Reverses Senescence Hallmarks in SARS-CoV-2 Infected Bronchial Epithelial Cells

SARS-CoV-2 infection has been recently shown to induce cellular senescence in vivo. A senescence-like phenotype has been reported in cystic fibrosis (CF) cellular models. Since the previously published data highlighted a low impact of SARS-CoV-2 on CFTR-defective cells, here we aimed to investigate the senescence hallmarks in SARS-CoV-2 infection in the context of a loss of CFTR expression/function. We infected WT and CFTR KO 16HBE14o-cells with SARS-CoV-2 and analyzed both the p21 and Ki67 expression using immunohistochemistry and viral and p21 gene expression using real-time PCR. Prior to SARS-CoV-2 infection, CFTR KO cells displayed a higher p21 and lower Ki67 expression than WT cells. We detected lipid accumulation in CFTR KO cells, identified as lipolysosomes and residual bodies at the subcellular/ultrastructure level. After SARS-CoV-2 infection, the situation reversed, with low p21 and high Ki67 expression, as well as reduced viral gene expression in CFTR KO cells. Thus, the activation of cellular senescence pathways in CFTR-defective cells was reversed by SARS-CoV-2 infection while they were activated in CFTR WT cells. These data uncover a different response of CF and non-CF bronchial epithelial cell models to SARS-CoV-2 infection and contribute to uncovering the molecular mechanisms behind the reduced clinical impact of COVID-19 in CF patients.

Secondary infections and long-term outcomes among hospitalized elderly and non-elderly patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and treated with baricitinib: a comparative study from the national centre of Hungary

Baricitinib is considered a first-line treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected adult patients with an associated cytokine storm syndrome (CSS). Our objective was to compare rates of secondary infections and long-term outcomes of elderly and non-elderly patients who received baricitinib for COVID-19. We conducted a single-centre observational study between November 2020 and September 2023, focusing on hospitalized adult SARS-CoV-2 patients with CSS, categorized as elderly (≥ 65 years) and non-elderly (< 65 years). Enrolment, severity stratification, and diagnosis of infectious complications followed predefined criteria. Outcomes of all-cause mortality and rates of non-severe and severe secondary infections were assessed at 1-year post-treatment initiation. Kaplan-Meier analysis was performed for survival analysis. In total, 490 patients were enrolled (median age 65 ± 23 (21-100) years (years, median ± IQR, min-max); 49.18% elderly; 59.59% male). Elderly patients were admitted to the hospital significantly earlier (7 ± 5 days vs. 8 ± 4 days; p = 0.02), experienced a higher occurrence of severe COVID-19 (121/241, 50.21% vs. 98/249, 39.36%; p = 0.02), and required the use of non-invasive ventilation at baseline (167/225, 74.22% vs. 153/236, 64.83%; p = 0.03). At 1 year, all-cause mortality was significantly higher in the elderly subgroup (111/241, 46.06% vs. 29/249, 11.65%; p < 0.01). At 90 days and 1 year, rates of any severe secondary infection were also more prevalent among the elderly (56/241, 23.24% vs. 37/249 14.86%; p = 0.02 and 58/241, 24.07% vs. 39/249, 15.66%; p = 0.02). In conclusion, elderly SARS-CoV-2-infected patients experience a more severe clinical course, higher secondary infection rates, and increased risk for long-term mortality, regardless of immunomodulatory therapy.

DNA damage response(DDR): a link between cellular senescence and human cytomegalovirus

The DNA damage response (DDR) is a signaling cascade that is triggered by DNA damage, involving the halting of cell cycle progression and repair. It is a key event leading to senescence, which is characterized by irreversible cell cycle arrest and the senescence-associated secretory phenotype (SASP) that includes the expression of inflammatory cytokines. Human cytomegalovirus (HCMV) is a ubiquitous pathogen that plays an important role in the senescence process. It has been established that DDR is necessary for HCMV to replicate effectively. This paper reviews the relationship between DDR, cellular senescence, and HCMV, providing new sights for virus-induced senescence (VIS).