Recovery of Innate Immune Cells and Persisting Alterations in Adaptive Immunity in the Peripheral Blood of Convalescent Plasma Donors at Eight Months Post SARS-CoV-2 Infection.

Ioannis V Kostopoulos,Evangelos Terpos,Eleni Korompoki,Pantelis Rousakis,Ioannis P Trougakos,Nikolaos Orologas-Stavrou,Maria Gavriatopoulou,Ioanna Charitaki,Ourania E Tsitsilonis,Chrysanthi Panteli,Efstathios Kastritis,Meletios-Athanasios Dimopoulos,Ioannis Ntanasis-Stathopoulos

doi:10.3390/microorganisms9030546

Ioannis V Kostopoulos, Evangelos Terpos + Show 11 more

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https://doi.org/10.3390/microorganisms9030546

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Abstract

Persisting alterations and unique immune signatures have been previously detected in the peripheral blood of convalescent plasma (CP) donors at approximately two months after initial SARS-CoV-2 infection. This article presents the results on the sequential analysis of 47 CP donors at a median time of eight months (range 7.5–8.5 months) post infection, as assessed by flow cytometry. Interestingly, our results show a significant variation of the relevant immune subset composition among CP donors. Regarding innate immunity, both non-classical monocytes, and CD11b- granulocytes had fully recovered at eight months post COVID-19 infection. Intermediate monocytes and natural killer (NK) cells had already been restored at the two-month evaluation and remained stable. Regarding adaptive immunity, the COVID-19-related skewed Th1 and Th2 cell polarization remained at the same levels as in two months. However, low levels of total B cells were detected even after eight months from infection. A persisting reduction of CD8+ Tregs and changes in the NKT cell compartment were also remarkable. CP donors present with a unique immune landscape at eight months post COVID-19 infection, which is characterized by the notable restoration of the components of innate immunity along with a persisting imprint of SARS-CoV-2 in cells of the adaptive immunity.

Highlights

The present analysis included 47 convalescent plasma (CP) donors with paired peripheral blood (PB) samples collected at a median of two and eight months post COVID-19 infection
COVID-19 is strongly associated with unique immune cascades, and several studies have reported the alterations in immune profiling following SARS-CoV-2 immune response [4,9,10,15]
We have previously reported a marginal increase of the total monocyte population in the PB of active COVID-19 patients, sensibly due to the generic recruitment of macrophages to the lung or other infected areas [13]

Summary

Introduction

Coronavirus disease 2019 (COVID-19) is caused by the potentially fatal and highly contagious via airborne transmission severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). The severity of COVID-19 largely varies among infected people, ranging from cases entirely asymptomatic [1], to milder conditions experiencing fever, cough, and tiredness, and to more serious cases suffering from pneumonia leading to acute respiratory distress syndrome and unrestrained multi-organ failure, which are often fatal [2]. SARS-CoV-2 infection are directly related to the preceding host’s immune status [3,4,5]. Factors related to more dysfunctional immunocompromised immune profiles, and higher risk of mortality, including increased age and certain underlying chronic medical conditions, like type 2 diabetes, cardiomyopathy, obesity, chronic obstructive pulmonary disease, and chronic kidney disease [6,7]

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