The impact of lymphoid memory cells in different ages of COVID-19 patients

Abstract

Coronaviruses are highly pathogenic and transmissible viruses. The SARS-CoV-2 virus that emerged in December 2019 is increasingly recognized as a serious, worldwide public health concern. Respiratory infections and the hyper-inflammatory response induced by SARS-CoV-2 play a key role in disease severity and death in infected COVID-19 patients. However, much uncertainty still exists about the pathogenesis and various effects of COVID-19 on immune system. It seems that memory T cells can reduce the severity of COVID-19 infection by inducing a protective immune response. Memory T cells along with protective antibodies are the main defenses and also protective barrier against recurrent COVID-19 infection. The role of Memory T cells varies in different ages and the severity of COVID-19 infection varies between children, adults and the elderly. Furthermore, the aim of this review is to evaluate the role of memory cells in mild, moderate and severe infected COVID-19 patients with different ages.

Incidence and outcome of SARS‐CoV‐2 infection in a pediatric kidney transplant recipient cohort from a single center in Northern Italy

“…In addition, according to cross‐protection to other coronaviruses in children, in vitro memory T cells that are specific to other pathogens, probably can play an important role in protective immunity arising from heterologous infectious agents. 9 Interestingly, Yuan et al have recently published data from a retrospective study performed at two COVID‐19 designated hospitals in China, showing that, in pediatric patients, the immune response was not excessive, with no “cytokine storm”. In contrast, in adult patients, an altered immune response was observed, characterized by evidently abnormal T‐cell inhibition and excessive cytokine production.…”

“…The possible reasons for this being that children have fewer comorbidities, do not smoke, have a lower ACE2 expression, and present a different inflammatory response, with higher numbers of B and T regulatory cells involved in immune tolerance, leading to a “less inflammatory” immune response. In addition, according to cross‐protection to other coronaviruses in children, in vitro memory T cells that are specific to other pathogens, probably can play an important role in protective immunity arising from heterologous infectious agents 9 . Interestingly, Yuan et al have recently published data from a retrospective study performed at two COVID‐19 designated hospitals in China, showing that, in pediatric patients, the immune response was not excessive, with no “cytokine storm”.…”

SARS-CoV-2 triggering autoimmune diseases

“…Over 80 million cases of Covid-19 have been confirmed universally, at a ∼2.2% case fatality rate that mostly happens in the 15-20% of the severe cases of the disease with bilateral interstitial pneumonia (5) . In these cases, acute respiratory distress syndrome (ARDS), characterized by the quick beginning of widespread inflammation in the lungs, is considered as the leading cause of mortality [4] , [6] , [7] , [8] , [9] , [10] .…”