Persistent SARS-CoV-2 presence is companied with defects in adaptive immune system in non-severe COVID-19 patients

Abstract

Defects in adaptive immune system, including reduced T cells and B cells, were frequently observed in non-severe COVID-19 patients with persistent SARS-CoV-2 shedding. Assessment of immune system could be clinically relevant for discharge management. AbstractBackground: COVID-19 has been widely spreading. We aim to examine adaptive immune cells in non-severe patients with persistent SARS-CoV-2 shedding.Methods 37 non-severe patients with persistent SARS-CoV-2 presence transferred to Zhongnan hospital of Wuhan University were retrospectively recruited to PP (persistently positive) group, which was further allocated to PPP group (n=19) and PPN group (n=18), according to their testing results after 7 days (N=negative).Epidemiological, demographic, clinical and laboratory data were collected and analyzed. Data from ageand sex-matched non-severe patients at disease onset (PA [positive on admission] patients, n=37), and lymphocyte subpopulation measurements from matched 54 healthy subjects were extracted for comparison. ResultsCompared with PA patients, PP patients had much improved laboratory findings, including WBCs, neutrophils, lymphocytes, neutrophil-to-lymphocyte ratio, albumin, AST, CRP, SAA, and IL-6. The absolute numbers of CD3 + T cells, CD4 + T cells, and NK cells were significantly higher in PP group than that in PA group, and were comparable to that in healthy controls. PPP subgroup had markedly reduced B cells and T cells compared to PPN group and healthy subjects. Finally, paired results of these lymphocyte subpopulations from 10 PPN patients demonstrated that the number of T cells and B cells significantly increased when the SARS-CoV-2 tests turned negative. ConclusionPersistent SARS-CoV-2 presence in non-severe COVID-19 patients is associated with reduced numbers of adaptive immune cells. Monitoring lymphocyte subpopulations could be clinically meaningful in 3 All rights reserved. No reuse allowed without permission.

Predictive monitoring and therapeutic immune biomarkers in the management of clinical complications of COVID-19

“…On the other hand, studying CD8 + T cells subsets, as the main effector cells in the direct killing of viral infected cells, can be helpful in determining the relative significance of T cell subsets and cellular immunity in the defensce against COVID-19 and its immunopathology [ 121 ]. Accordingly, similar to the acute phase of SARS and MERS diseases, COVID-19 patients with severe symptoms exhibit an extreme decline in total CD4+ and CD8 + T cells in their circulation [ 122 ], while patients with mild symptoms have normal to slightly higher T cell counts [ 123 ]. This decrease in T cells is likely to be caused by high levels of pro-inflammatory cytokines such as IL-6, IFN-I, and TNF-α in peripheral blood [ 71 , 82 ].…”

A systematic review uncovers a wide-gap between COVID-19 in humans and animal models

“…Viral and immunopathological studies revealed distinct patterns between mild and severe or critical forms of COVID-19 4,[17][18][19][20][21][22][23][24][25] . Both severe and critically ill patients displayed higher viral load in the upper respiratory tract than mild cases, together with delayed clearance overtime 17,18 .…”

“…Both severe and critically ill patients displayed higher viral load in the upper respiratory tract than mild cases, together with delayed clearance overtime 17,18 . Likewise, they presented with lymphopenia due to a decrease in CD4+ and CD8+ T cells, as well as T cells exhaustion accompanied by a marked inflammatory response [20][21][22][23][24][25] . Pro-and anti-inflammatory cytokines and chemokines concentrations were increased systemically and locally in the lung and correlated with severity [20][21][22] .…”

Evidence of a wide gap between COVID-19 in humans and animal models: a systematic review

“…Viral and immunopathological studies revealed distinct patterns between mild and severe or critical forms of COVID-19 [4,5,9,[21][22][23][24][25][26][27]. Both severe and critically ill patients displayed higher viral load in the upper respiratory tract than mild cases, together with delayed clearance overtime [21,22].…”

“…Both severe and critically ill patients displayed higher viral load in the upper respiratory tract than mild cases, together with delayed clearance overtime [21,22]. Likewise, they presented with lymphopenia due to a decrease in CD4+ and CD8+ T cells, as well as T cell exhaustion accompanied by a marked inflammatory response [5,9,[24][25][26][27]. Pro-and anti-inflammatory cytokines and chemokine concentrations were increased systemically and locally in the lung and correlated with severity [5,9,24].…”