Immune-Inflammatory Parameters in COVID-19 Cases: A Systematic Review and Meta-Analysis

Xudong Feng; Shuangshuang Li; Qiang Sun; Jiaqi Zhu; Bo Chen; Maoming Xiong; Guodong Cao

doi:10.3389/fmed.2020.00301

Immune-Inflammatory Parameters in COVID-19 Cases: A Systematic Review and Meta-Analysis

Front Med (Lausanne). 2020 Jun 9:7:301. doi: 10.3389/fmed.2020.00301. eCollection 2020.

Authors

Xudong Feng¹, Shuangshuang Li², Qiang Sun³, Jiaqi Zhu¹, Bo Chen⁴, Maoming Xiong⁴, Guodong Cao⁴

Affiliations

¹ State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, College of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China.
² Department of Microbiology and Center of Infectious Disease, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.
³ Jiangsu Key Laboratory of Biological Cancer, Cancer Institute, Xuzhou Medical University, Xuzhou, China.
⁴ Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China.

Abstract

Background: The recent outbreak of coronavirus disease 2019 (COVID-19) has been rapidly spreading on a global scale and poses a great threat to human health. Acute respiratory distress syndrome, characterized by a rapid onset of generalized inflammation, is the leading cause of mortality in patients with COVID-19. We thus aimed to explore the effect of risk factors on the severity of the disease, focusing on immune-inflammatory parameters, which represent the immune status of patients. Methods: A comprehensive systematic search for relevant studies published up to April 2020 was performed by using the PubMed, Web of Science, EMBASE, and China National Knowledge Internet (CNKI) databases. After extracting all available data of immune-inflammatory indicators, we statistically analyzed the risk factors of severe and non-severe COVID-19 patients with a meta-analysis. Results: A total of 4,911 patients from 29 studies were included in the final meta-analysis. The results demonstrated that severe patients tend to present with increased white blood cell (WBC) and neutrophil counts, neutrophil-lymphocyte ratio (NLR), procalcitonin (PCT), C-reaction protein (CRP), erythrocyte sedimentation rate (ESR), and Interleukin-6 (IL-6) and a decreased number of total lymphocyte and lymphocyte subtypes, such as CD4+ T lymphocyte and CD8+ T lymphocyte, compared to the non-severe patients. In addition, the WBC count>10 × 10⁹/L, lymphocyte count<1 × 10⁹/L, PCT>0.5 ng/mL, and CRP>10 mg/L were risk factors for disease progression in patients with COVID-19 (WBC count>10 × 10⁹/L: OR = 2.92, 95% CI: 1.96-4.35; lymphocyte count<1 × 10⁹/L: OR = 4.97, 95% CI: 3.53-6.99; PCT>0.5 ng/mL: OR = 6.33, 95% CI: 3.97-10.10; CRP>10 mg/L: OR = 3.51, 95% CI: 2.38-5.16). Furthermore, we found that NLR, as a novel marker of systemic inflammatory response, can also help predict clinical severity in patients with COVID-19 (OR = 2.50, 95% CI: 2.04-3.06). Conclusions: Immune-inflammatory parameters, such as WBC, lymphocyte, PCT, CRP, and NLR, could imply the progression of COVID-19. NLR has taken both the levels of neutrophil and lymphocyte into account, indicating a more complete, accurate, and reliable inspection efficiency; surveillance of NLR may help clinicians identify high-risk COVID-19 patients at an early stage.

Keywords: COVID-19; immune-inflammatory parameters; meta-analysis; neutrophil-lymphocyte ratio; risk factor.

Publication types

Systematic Review