Thymic Dysfunction and Atrophy in COVID-19 Disease Complicated by Inflammation, Malnutrition and Cachexia
23 Pages Posted: 30 Jul 2020 Last revised: 31 Aug 2020
Date Written: July 13, 2020
The current COVID-19 pandemic sweeping across developing countries is putting millions at risk of protein-energy malnutrition by pushing them into poverty and disrupting the global food supply chain. COVID-19 disease and protein-energy malnutrition are both known to cause immune dysfunction. The objective of this review is to highlight the known pathogenetic mechanisms underlying immune dysfunction in COVID-19 disease and malnutrition, and thereby identify preventive and therapeutic interventions that would help limit and contain the global health impact of this pandemic. Severe COVID-19 disease is characterized by dysregulation of myeloid compartments and lymphopenia. Lymphopenia is often protracted and outlasts the cytokine storm, suggesting underlying thymic dysfunction or involution. The thymus is considered a barometer of malnutrition, and leptin deficiency induced by protein-energy malnutrition can lead to thymic dysfunction and atrophy. Immune dysfunction in COVID-19 disease and malnutrition may be further increased by comorbidities including zinc and vitamin deficiencies, hyperinflammation, and stress. Thymic dysfunction or involution, especially in children, can potentially slow the recovery from COVID-19 disease and increase the risk of other infections. National governments and international organizations including WHO, World Food Program, and UNICEF should institute measures to ensure provision of food including micronutrients for the poor, thereby mitigating the health impact of the COVID-19 pandemic, especially amongst children in developing countries.
Note: Conflict of Interest: AG has filed provisional patents for use of Ramatroban as an immunotherapy to treat COVID-19 infection. (Gupta, A.Use of Ramatrobanas a therapeutic agent for prevention and treatment of viral infections including COVID-Application no. 63/003,286 filed on March 31, 2020; and Gupta A. Use of a DP2 antagonist such as Ramatroban as a therapeutic agent for treatment of adults
with viral infection including COVID-19 Provisional Patent Application no. 63/005,205 filed on April 3, 2020). Other authors have not declared conflict of interest.
Funding: None to declare
Keywords: COVID-19, protein-calorie malnutrition, thymic atrophy, inflammation, zinc, cachexia, lymphopenia, leptin, stress, glucocorticoids
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