Association of Peripheral Lymphocyte and the Subset Levels With the Progression and Mortality of COVID-19: A Systematic Review and Meta-Analysis.

Qun Lu,Zhengyin Wang,Yanrong Zhao,Ping Zhong,Ping Tao,Yuan Yin

doi:10.3389/fmed.2020.558545

Qun Lu, Zhengyin Wang + Show 4 more

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https://doi.org/10.3389/fmed.2020.558545

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Abstract

Current evidence is controversial in the association between peripheral lymphocyte levels and the progression and mortality of Corona Virus Disease 2019 (COVID-19), and this meta-analysis aimed to clarify the association. A systematic search was conducted in public databases to identify all relevant studies, and the study-specific odds ratio (OR) and 95% confidence intervals (CI) were pooled. Finally, 16 studies were identified with a total of 1,873 progressive COVID-19 cases and 5,177 stable COVID-19 cases. In COVID-19 progression, lymphocyte levels showed a significant negative correlation (OR: 0.68, 95% CI: 0.51–0.89), but it was not significant in the subsets of CD3+ T cells (OR: 0.97, 95% CI: 0.93–1.02), CD4+ T cells (OR: 0.93, 95% CI: 0.80–1.08), CD8+ T cells (OR: 0.96, 95% CI: 0.92–1.00), B cells (OR: 0.98, 95% CI: 0.92–1.04), or NK cells (OR: 0.80, 95% CI: 0.61–1.04). In COVID-19 mortality, lymphocyte levels showed a significant negative correlation (OR: 0.41, 95% CI: 0.20–0.85), but it was not significant in the subsets of CD3+ T cells (OR: 0.95, 95% CI: 0.86–1.05), CD4+ T cells (OR: 1.06, 95% CI: 0.86–1.31), CD8+ T cells (OR: 0.38, 95% CI: 0.14–1.01), B cells (OR: 0.98, 95% CI: 0.92–1.04), or NK cells (OR: 0.80, 95% CI: 0.61–1.04). In conclusion, current evidence suggests a significant negative association of peripheral lymphocyte levels with COVID-19 progression and mortality, but it was not significant in the subsets of CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells, and NK cells.

Highlights

In December 2019, an outbreak of pneumonia of unknown cause occurred in Wuhan, and rapidly spread throughout the world [1]
The studies were included if they met the following criteria: (i) all hospitalized patients discussed had a definite diagnosis of COVID-19; (ii) the patients discussed were divided into the progressive group [e.g., admission to an intensive care unit (ICU), the use of mechanical ventilation, or death] or the stable group during the hospitalization; (iii) the study evaluated the association of the baseline lymphocytes levels or the main subtypes of CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells, or NK cells with the COVID-19 progression or mortality; (iv) presented relative risk (RR), odds ratio (OR), or hazard ratio (HR) estimates with 95% confidence intervals (CI)
Severe cases had a lower level of lymphocytes, CD4+ T cells, CD8+ T cells, and B cells than mild cases, which was similar in severe acute respiratory syndrome (SARS) [20, 21]

Summary

Introduction

In December 2019, an outbreak of pneumonia of unknown cause occurred in Wuhan, and rapidly spread throughout the world [1]. The pathogen was confirmed to be a distinct clade of the βcoronavirus associated with human severe acute respiratory syndrome (SARS) [2]. The novel virus was officially named SARS-CoV-2, with the disease termed COVID-19. Epidemiological data demonstrated high infectivity in SARS-CoV-2 and high mortality in multiple cohorts. It was important to identify laboratory parameters capable of discriminating the COVID-19 patients at high risk of progression or mortality, which would help physicians to provide timely intervention and improve the patients’ prognosis

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