Microorganisms (Mar 2021)

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

DOI
https://doi.org/10.3390/microorganisms9030546
Journal volume & issue
Vol. 9, no. 3
p. 546

Abstract

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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.

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