Enhanced Thymopoiesis as an Alternative Therapeutic Option for COVID-19

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Gerontol Geriatr Res. 2021; 7(2): 1054.

Enhanced Thymopoiesis as an Alternative Therapeutic Option for COVID-19

Genebat M1,2#, Tarancón-Díez L3#, Calderón A1, Muñoz-Fernández MA3 and Leal M4*

1Department of Internal Medicine, Hospital Fátima, Sevilla, Spain

2Department of Emergency, Virgen del Rocío University Hospital, Sevilla, Spain

3Immunology Section, Laboratorio Inmuno-Biología Molecular (LIBM), Hospital General Universitario Gregorio Marañón, Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain

4Infectious Diseases and Immunology Unit, Internal Medicine Department, Hospital Viamed Santa Ángela de la Cruz, Sevilla, Spain

#Contributed Equally to this Work

*Corresponding author: Leal M, Infectious Diseases and Immunology Unit, Internal Medicine Department, Hospital Viamed Santa Ángela de la Cruz, Sevilla, Spain

Received: April 20, 2021; Accepted: May 17, 2021; Published: May 24, 2021


The pandemic caused by SARS-CoV-2 infection (COVID-19 disease) has expanded worldwide. Currently, it is well known that advanced age is an independent predictor of mortality and severe clinical outcome, apart from other comorbidities [1]. Underlying molecular and cellular mechanisms that could explain the severe clinical outcome among elderly subjects are not well known [2], although it has been described that both immunosenescence and a low-level systemic inflammation (inflamm-aging) could also play a relevant role [3,4].

Now a days, apart from an effective vaccine development, research efforts are focused on therapeutic approaches that could minimize both the viral replication and the further inflammatory cascade driving to respiratory distress and multiorgan failure; however, up to now, no specific therapy for SARS-CoV-2 infection has been established [5]. Awaiting for definitive and conclusive results from prospective clinical trials, antiviral and immunomodulatory drugs currently employed in SARS-CoV-2-infected subjects are based on their biological plausibility according to the mechanism of action or in vitro efficacy, but not in a definitive scientific evidences.

Taken altogether, alternative hypothesis about underlying mechanisms driving to an impaired clinical outcome in COVID-19 disease are required. In this sense, even the universally accepted role of the cytokine storm has been questioned [6]. Hence, the greater hypothesis is considered the greater and more beneficial therapeutic options could be tested. Recently, our group has suggested that thymic dysfunction could play a relevant role in the impaired clinical outcome observed in elderly SARS-CoV-2-infected subjects [7]. Thus, the main objective of the present opinion paper is to explore a new therapeutic option for COVID-19 disease, based on enhancing thymic function.

Thymic Function in Adulthood

It has been traditionally accepted that thymic function begins its involution in childhood and continues in adolescence under the effect of sexual hormones, so that just thymic vestiges are observed in the elderly. However, it is well known that thymic function may be present and enhanced in different clinical scenarios. First of all, Mackall et al. [8] reported for the first time how thymic function increased in children and adults with chemotherapy-induced lymphopenia. This observation has been confirmed in other clinical settings [9,10], including HIV-infected subjects under suppressive antiretroviral therapy (Figure 1). Additionally, it has been shown that even in the elderly certain thymopoiesis remains (Figure 2) and it is directly associated with T-cell homeostasis and survival in healthy elderly subjects [11-13].