Severe COVID-19 and aging: are monocytes the key?

Area of Science:

• Immunology
• Geroscience
• Infectious Diseases

Background:

• Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disproportionately affects older adults, leading to severe coronavirus disease 2019 (COVID-19) and mortality.
• COVID-19 is characterized by cytokine storm, acute respiratory distress syndrome, and systemic inflammation.
• Current understanding of severe COVID-19 determinants is largely observational.

Purpose of the Study:

• To review emerging evidence on the role of monocytes in COVID-19 cytokine storm and associated pathologies.
• To describe shared changes in monocyte function and phenotype in aging and severe COVID-19.
• To highlight the innate immune system as a therapeutic target for COVID-19.

Main Methods:

• Review of emerging scientific literature and evidence.
• Analysis of monocyte function and phenotype in the context of aging and COVID-19.
• Discussion of challenges in pre-clinical and in vivo studies of SARS-CoV-2.

Main Results:

• Monocytes are identified as principal players in COVID-19 cytokine storm and related pathologies.
• Shared alterations in monocyte function and phenotype in aging and severe COVID-19 suggest a mechanism for increased morbidity and mortality in older adults.
• The innate immune system is a potential therapeutic target for COVID-19.

Conclusions:

• Monocyte-targeted therapies could be crucial for treating severe COVID-19, particularly in elderly populations.
• Development of SARS-CoV-2-susceptible animal models for aging studies is essential.
• Collaborative efforts in geroscience are needed to advance COVID-19 therapies for older adults.