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Cell Host Microbe . 2020 Jun 10

Complex Immune Dysregulation in COVID-19 Patients with Severe Respiratory Failure

Evangelos J Giamarellos-Bourboulis, Mihai G Netea, Nikoletta Rovina, Karolina Akinosoglou, Anastasia Antoniadou, Nikolaos Antonakos, Georgia Damoraki, Theologia Gkavogianni, Maria-Evangelia Adami, Paraskevi Katsaounou, Maria Ntaganou, Magdalini Kyriakopoulou, George Dimopoulos, Ioannis Koutsodimitropoulos, Dimitrios Velissaris, Panagiotis Koufargyris, Athanassios Karageorgos, Konstantina Katrini, Vasileios Lekakis, Mihaela Lupse, Antigone Kotsaki, George Renieris, Danai Theodoulou, Vassiliki Panou, Evangelia Koukaki, Nikolaos Koulouris, Charalambos Gogos, Antonia Koutsoukou

Proper management of COVID-19 mandates better understanding of disease pathogenesis. The sudden clinical deterioration 7-8 days after initial symptom onset suggests that severe respiratory failure (SRF) in COVID-19 is driven by a unique pattern of immune dysfunction. We studied immune responses of 54 COVID-19 patients, 28 of whom had SRF. All patients with SRF displayed either macrophage activation syndrome (MAS) or very low human leukocyte antigen D related (HLA-DR) expression accompanied by profound depletion of CD4 lymphocytes, CD19 lymphocytes, and natural killer (NK) cells. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production by circulating monocytes was sustained, a pattern distinct from bacterial sepsis or influenza. SARS-CoV-2 patient plasma inhibited HLA-DR expression, and this was partially restored by the IL-6 blocker Tocilizumab; off-label Tocilizumab treatment of patients was accompanied by increase in circulating lymphocytes. Thus, the unique pattern of immune dysregulation in severe COVID-19 is characterized by IL-6-mediated low HLA-DR expression and lymphopenia, associated with sustained cytokine production and hyper-inflammation.

PMID: 32320677