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. 2024 Nov 19;14(1):28617.
doi: 10.1038/s41598-024-75920-1.

Altered leukocyte pattern and inflammatory markers in unvaccinated long covid patients: a cross-sectional study

Elem Cristina Rodrigues Chaves  1 , Juarez Antônio Simões Quaresma #  1 , Maria Helena Cruz Rodrigues  2 , Daniel Carvalho de Menezes  1 , Igor Costa de Lima  1 , Jorge Rodrigues de Sousa  3 , Vanessa Costa Alves Galúcio  1 , Maria Alice Freitas Queiroz  4 , Igor Brasil-Costa  5 , Maria Clara Barros  6 , Ândrea Ribeiro-Dos-Santos  6 , Antonio Carlos Rosário Vallinoto #  4 , Luiz Fábio Magno Falcão #  1   7 , Patrícia Danielle Lima de Lima  8
Affiliations

Altered leukocyte pattern and inflammatory markers in unvaccinated long covid patients: a cross-sectional study

Elem Cristina Rodrigues Chaves et al. Sci Rep. .

Abstract

Long Covid results from the damage caused by SARS-CoV-2, involving the release of cytokines and the continuous activation of immune cells. This cross-sectional study investigates leukocyte and cytokine profiles in Long Covid patients in the Amazon, a region where such studies are limited. Blood samples were analysed for differential leukocyte counts and cytokine levels. We suggest elevated lymphocyte counts in hospitalised patients and those with severe COVID-19. Higher eosinophil counts were observed in patients with up to three months of Long Covid, and increased monocyte counts in those with up to six months. IL-2 levels were higher in patients with fewer symptoms and Long Covid duration of more than three months, whereas IL-10 may remain elevated for up to 12 months. We suggest positive correlations between neutrophils, monocytes, eosinophils, and lymphocytes with different cytokines (IFN-γ, IL-6, IL-4, IL-17a, IL-2). Women were associated with lower hospitalisation rates and longer durations of Long Covid; increased lymphocyte counts were linked to hospitalisation due to COVID-19, while higher monocyte counts were associated with Long Covid durations of up to six months. We suggest that Long Covid patients may exhibit alterations in inflammatory markers, indicating a persistently pro-inflammatory microenvironment that tends to diminish after 12 months of Long Covid.

Keywords: Cytokines; Leukocyte count; Long covid.

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Conflict of interest statement

Declarations Competing interests The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Spearman’s correlation coefficient (r) between different leukocyte counts and cytokines according to time of Long Covid [Spearman’s correlation: (a) I-V: leukocytes vs. cytokines in ≤3 months of Long Covid; (b) I-V: leukocytes vs. cytokines in >3 months of Long Covid; (c) I-V: leukocytes vs. cytokines in >6 months of Long Covid; (d) I-V: leukocytes vs. cytokines in >12 months of Long Covid. †Statistically significant].
Fig. 2
Fig. 2
Flowchart of the process of recruiting and allocating study groups. [¹Characterisation considering WHO recommendations].
See this image and copyright information in PMC

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