Dados do Trabalho

Título

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

Introdução

Long Covid/CL is characterized by persistent symptoms after the acute phase (>four weeks) of SARS-CoV-2 infection, resulting in increased morbidity. Studies have been using inflammatory biomarkers to understand the context of CL, and in a population that is poorly studied like the Amazon region, understanding the immunological complexity becomes essential.

Objetivo (s)

This study aims to Correlate the profiles of leukocytes and cytokines in patients with Long Covid.

Material e Métodos

This observational, cross-sectional, descriptive analytical study was conducted in accordance with STROBE and was approved by the Ethics Committee for Research Involving Human Beings of the State University of Pará (opinion no. 4.252.664). Clinical data were initially obtained, followed by blood collection for the analysis of leukogram and cytokine levels, which were analysed according to the outcome groups.

Resultados e Conclusão

Among the 341 individuals in the study, 224 were female, 195 were aged between 39 and 60 years (mean of 49.6), 171 reported comorbidity and 106 were hospitalised in COVID-19’s acute phase, with a mean time of 19.5 days (SD±18.5). The average number of symptoms in Long Covid was 3.4 (SD±2.2) and Long Covid duration ranged from 32–985 days, with a 362.9 days (SD±212.1) average. The serum levels of neutrophils, lymphocytes, and IFN-γ were elevated in patients hospitalized during the acute phase of COVID-19. Eosinophils, monocytes, IL-10, and IL-2 showed elevation in patients with more than six symptoms in Long Covid. Among individuals with up to 3 months of Long Covid, there was eosinophilia; however, those with Long Covid over 12 months exhibited monocytosis. In correlation, individuals with Long Covid up to 3 months showed significant correlations between leukocytes and pro-inflammatory cytokines (IL-2, IL-6, and IFN-γ), with the correlations decreasing after 6 months, maintaining only neutrophils and IFN-γ after 12 months. Additionally, those hospitalized in the acute phase had a risk of neutrophilia and lymphocytosis, and the persistence of more than six symptoms was associated with basophilia, eosinophilia, monocytosis and lymphocytosis. In conclusion, the increased levels of leukocyte and cytokines, especially IFN-γ and monocyte maintenance proportional to the duration of Long Covid, may indicate a chronic pro-inflammatory microenvironment.

Palavras Chave

: Cytokines; Long Covid; Leukocyte Count.