SARS-CoV-2 infection induces mixed M1/M2 phenotype in circulating monocytes and alterations in both dendritic cell and monocyte subsets

Abstract

Clinical manifestations of SARS-CoV-2 infection range from mild to critically severe. The aim of the study was to highlight the immunological events associated with the severity of SARS-CoV-2 infection, with an emphasis on cells of innate immunity. Thirty COVID-19 patients with mild/moderate symptoms and 27 patients with severe/critically severe symptoms were recruited from the Clinical Center of Kragujevac during April 2020. Flow cytometric analysis was performed to reveal phenotypic and functional alterations of peripheral blood cells and to correlate them with the severity of the disease. In severe cases, the number of T and B lymphocytes, dendritic cells, NK cells, and HLA-DR-expressing cells was drastically decreased. In the monocyte population proportion between certain subsets was disturbed and cells coexpressing markers of M1 and M2 monocytes were found in intermediate and non-classical subsets. In mild cases decline in lymphocyte number was less pronounced and innate immunity was preserved as indicated by an increased number of myeloid and activated dendritic cells, NK cells that expressed activation marker at the same level as in control and by low expression of M2 marker in monocyte population. In patients with severe disease, both innate and adoptive immunity are devastated, while in patients with mild symptoms decline in lymphocyte number is lesser, and the innate immunity is preserved.

Monocyte Distribution Width (MDW) as novel inflammatory marker with prognostic significance in COVID-19 patients

“…In perspective, new investigations on MDW testing in larger series of patients and in different COVID-19 settings are needed to overcome the limitations of this ‘proof-of-concept’ real-life study, and possibly to extend its results, in particular aiming to: (1) better explore MDW correlations with inflammatory serum biomarkers, as well as with immunological subsets of circulating monocytes, dendritic cells and lymphocytes 26 , 27 ; (2) prospectively evaluate the prognostic roles of MDW in COVID-19 patients, either as ‘single assessment’, or as ‘pattern evaluation’ in MDW dynamics, possibly allowing consistent predictions on short- and long-term clinical evolutions; (3) disclose possible impact of different medications on MDW values; (4) implement the prognostic significance of MDW into multiparametric predictive models. In particular, by considering that MDW test provides peculiar information on actual inflammatory state, MDW evaluation could usefully be included in prognostic models of organ impairment assessment (e.g.…”

Monocyte Distribution Width (MDW) as novel inflammatory marker with prognostic significance in COVID-19 patients

“…In perspective, new investigations on MDW test performance in different COVID-19 settings are needed to overcome the limitations of this 'proof-of-principle' study, and possibly to extend its results, in particular aiming to: (i) better explore MDW correlations with in ammatory serum biomarkers, as well as with immunological subsets of circulating monocytes, dendritic cells and lymphocytes [26,27]; (ii) speci cally evaluate prognostic roles of MDW test in COVID-19 patients, either as 'single assessment' or 'pattern evaluation' within MDW dynamics, possibly allowing consistent predictions on short-and long-term clinical evolutions; (iii) implement the prognostic signi cance of MDW into multiparametric predictive models. In particular, by considering that MDW test could add peculiar information on the ongoing in ammatory state, MDW evaluation could usefully be included in the prognostic scoring systems for multi-organ impairment in sepsis, such as SOFA, as indeed recently proposed [11].…”

Monocyte Distribution Width As A Novel Sepsis Indicator in COVID-19 Patients

“…19,20 Certain subsets were disturbed and cells co-expressing markers of M1 and M2 monocytes were found in intermediate and non-classical subsets. 21 Those overactivated monocytes play a role in the cytokine storm that leads to the acute pulmonary injury and acute respiratory distress syndrome (ARDS) in COVID-19 patients. 22 Initially in COVID-19 patients there may be monocytopaenia that is corrected on the fth day onwards with abnormal activated monocytes characterized by marked anisocytosis, cytoplasmic vacuolisation and paucity of granules.…”