Residual persistence of cytotoxicity lymphocytes and regulatory T cells in patients with severe coronavirus disease 2019 over a 1-year recovery process

Yumi Mitsuyama; Kazuma Yamakawa; Katsuhide Kayano; Miho Maruyama; Yutaka Umemura; Takeshi Wada; Satoshi Fujimi

doi:10.1002/ams2.803

Residual persistence of cytotoxicity lymphocytes and regulatory T cells in patients with severe coronavirus disease 2019 over a 1-year recovery process

Acute Med Surg. 2022 Oct 26;9(1):e803. doi: 10.1002/ams2.803. eCollection 2022 Jan-Dec.

Authors

Yumi Mitsuyama^{1

2}, Kazuma Yamakawa³, Katsuhide Kayano³, Miho Maruyama¹, Yutaka Umemura¹, Takeshi Wada⁴, Satoshi Fujimi¹

Affiliations

¹ Division of Trauma and Surgical Critical Care Osaka General Medical Center Osaka Japan.
² Department of Traumatology and Acute Critical Medicine Osaka University Graduate School of Medicine Osaka Japan.
³ Department of Emergency and Critical Care Medicine Osaka Medical and Pharmaceutical University Takatsuki Japan.
⁴ Division of Acute and Critical Care Medicine, Department of Anesthesiology and Critical Care Medicine Hokkaido University Faculty of Medicine Sapporo Japan.

Abstract

Aim: To clarify the immune cellular changes in critically ill patients recovering from coronavirus disease 2019 (COVID-19).

Methods: The immune response of peripheral blood mononuclear cells from patients with severe COVID-19 in different stages of recovery (3, 6, and 12 months from hospitalization) was evaluated by single-cell mass cytometry. Immunological changes in patients were compared with those in age-matched healthy donors.

Results: Three patients with severe COVID-19 were compared with four healthy donors. In the patients, there was an increase in the cell density of CD4- and CD8-positive T lymphocytes, and B cells, over the course of the recovery period. CD4- and CD8-positive T lymphocytes expressing T-bet and granzyme B (Gzm B) in patients were abundant during all recovery periods. The level of regulatory T cells remained high throughout the year. The levels of natural killer (NK) cells in patients were higher than in those in the healthy donors, and the frequency of CD16⁺ NK cells expressing Gzm B increased throughout the year.

Conclusion: Patients recovering from severe COVID-19 showed persistence of cytotoxic lymphocytes, NK cells, and regulatory T cells throughout the posthospitalization year of recovery.

Keywords: CD4; CD8; CyTOF; NK; Treg; T‐bet; cytotoxicity; granzyme B; long COVID.