Critically Ill Coronavirus Disease 2019 Patients Exhibit Hyperactive Cytokine Responses Associated With Effector Exhausted Senescent T Cells in Acute Infection.

BACKGROUND

Coronavirus disease 2019 (COVID-19) can progress to severe pneumonia with respiratory failure and is aggravated by the deregulation of the immune system causing an excessive inflammation including the cytokine storm.

METHODS

In this study, we report that severe acutely infected patients have high levels of both type-1 and type-2 cytokines.

RESULTS

Our results show abnormal cytokine levels upon T-cell stimulation, in a nonpolarized profile. Furthermore, our findings indicate that this hyperactive cytokine response is associated with a significantly increased frequency of late-differentiated T cells with particular phenotype of effector exhausted/senescent CD28-CD57+ cells. Of note, we demonstrated for the first time an increased frequency of CD3+CD4+CD28-CD57+ T cells with expression of programmed death 1, one of the hallmarks of T-cell exhaustion.

CONCLUSIONS

These findings reveal that COVID-19 is associated with acute immunodeficiency, especially within the CD4+ T-cell compartment, and points to possible mechanisms of loss of clonal repertoire and susceptibility to viral relapse and reinfection events.