An Account of Immune Senescence in the Clinical Pathophysiology of COVID-19 Infection in Aging

Aging During the Pandemic: Untangling the Complexities of COVID-19 and Geriatric Care

The COVID-19 pandemic has posed unprecedented challenges to the global healthcare system, with the elderly population being particularly vulnerable. This comprehensive review synthesizes the findings from publications in "Aging and Disease", highlighting the unique challenges older adults encountered during the pandemic and providing solutions thereof. These studies provide invaluable insights into the elderly population's vulnerabilities and needs during the COVID-19 pandemic. The susceptibility to the virus in older individuals remains debatable, and research on the clinical picture of COVID-19 in older populations has yielded insights into clinical features, molecular mechanisms, and potential therapeutic strategies. This review intends to shed light on the need of sustaining physical and mental well-being among older adults during the periods of lockdown by extensively exploring these concerns and emphasizing the need for targeted interventions and support systems for this population. Ultimately, the findings of these studies contribute to developing more effective and comprehensive approaches to managing and mitigating the risks posed by the pandemic to the elderly.

Liver alterations and detection of SARS-CoV-2 RNA and proteins in COVID-19 autopsies

The most severe alterations in Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection are seen in the lung. However, other organs also are affected. Here, we report histopathologic findings in the liver and detection of viral proteins and RNA in COVID-19 autopsies performed at the Semmelweis University (Budapest, Hungary). Between March 2020 through March 2022, 150 autopsies on patients who died of COVID-19 were analyzed. Cause-of-death categories were formed based on the association with SARS-CoV-2 as strong, contributive, or weak. Samples for histopathologic study were obtained from all organs, fixed in formalin, and embedded in paraffin (FFPE). Immunohistochemical study (IHC) to detect SARS-CoV-2 spike protein and nucleocapsid protein (NP), CD31, claudin-5, factor VIII, macrosialin (CD68), and cytokeratin 7, with reverse transcriptase polymerase chain reaction (RT-PCR), and in situ hybridization (ISH, RNAscope®) for SARS-CoV-2 RNA were conducted using FFPE samples of livers taken from 20 autopsies performed ≤ 2 days postmortem. All glass slides were scanned; the digital images were evaluated by semiquantitative scoring and scores were analyzed statistically. Steatosis, single-cell and focal/zonal hepatocyte necrosis, portal fibrosis, and chronic inflammation were found in varying percentages. Sinusoidal ectasia, endothelial cell disruption, and fibrin-filled sinusoids were seen in all cases; these were assessed semiquantitatively for severity (SEF scored). SEF scores did not correlate with cause-of-death categories (p = 0.92) or with severity of lung alterations (p = 0.96). SARS-CoV-2 RNA was detected in 13/20 cases by PCR and in 9/20 by ISH, with IHC demonstration of spike protein in 4/20 cases and NP in 15/20. Viral RNA and proteins were located in endothelial and Kupffer cells, and in portal macrophages, but not in hepatocytes and cholangiocytes. In conclusion, endothelial damage (SEF scores) was the most common alteration in the liver and was a characteristic, but not specific alteration in COVID-19, suggesting an important role in the pathogenesis of COVID-19-associated liver disease. Detection of SARS-CoV-2 RNA and viral proteins in liver non-parenchymal cells suggests that while the most extended primary viral cytotoxic effect occurs in the lung, viral components are present in other organs too, as in the liver. The necrosis/apoptosis and endothelial damage associated with viral infection in COVID-19 suggest that those patients who survive more severe COVID-19 may face prolonged liver repair and accordingly should be followed regularly in the post-COVID period.

Promoting autophagy to mitigate coronavirus disease pathology in the elderly

In this commentary, we highlight autophagy's important function, while identifying potential therapeutic targets for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the elderly. Autophagy's decline in the elderly causes increased cell senescence and a dysregulated immune system. As this demographic often faces decreased vaccine-provided immunity, coronavirus disease 2019 treatments must be developed. We discuss a recent study by Acharya et al. (2022) that found that SF2523 induced autophagy, reducing SARS-CoV-2 replication. Furthermore, across varying dosages, SF2523 was shown to have a synergistic effect with remdesivir or MU-UNMC. Consequently, we believe that SF2523, alone or with other anti-virals, is a promising potential therapeutic for preventing SARS-CoV-2-related mortalities.

Secondary immunodeficiencies: An overview

OBJECTIVE

To review the different causes of secondary immunodeficiencies and provide clinicians with an updated overview of potential factors that contribute to immunodeficiency.

DATA SOURCES

Recent published literature obtained through PubMed database searches, including research articles, review articles, and case reports.

STUDY SELECTIONS

PubMed database searches were conducted using the following keywords: immunodeficiency, antibody deficiency, immunosuppressive drugs, genetic syndrome, malignancy, HIV infection, viral infection, secondary immunodeficiency, nutrition, prematurity, aging, protein-losing enteropathy, nephropathy, trauma, space travel, high altitude, and ultraviolet light. Studies published in the last decade and relevant to the pathogenesis, epidemiology, and clinical characteristics of secondary immunodeficiencies were selected and reviewed.

RESULTS

Researchers continue to investigate and report abnormal immune parameters in the different entities collectively known as secondary immunodeficiencies. Immunodeficiency might occur as a consequence of malnutrition, metabolic disorders, use of immunosuppressive medications, chronic infections, malignancies, severe injuries, and exposure to adverse environmental conditions. The neonate and the elderly may have decreased immune responses relative to healthy adults. Each of these conditions may present with different immune defects of variable severity. The acquired immunodeficiency syndrome results from infections by the human immunodeficiency virus, which targets CD4 T cells leading to defective immune responses. Rituximab is a monoclonal antibody that targets CD20 B cells, and its use might result in persistent hypogammaglobulinemia.

CONCLUSION

Clinicians should consider secondary immunodeficiencies in the differential diagnosis of a patient with recurrent infections and abnormal immunologic evaluation. The use of biological agents for the treatment of inflammatory conditions and malignancies is an increasingly important cause of secondary immunodeficiency.