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Meta-Analysis
. 2022 Jan;94(1):211-221.
doi: 10.1002/jmv.27297. Epub 2021 Aug 31.

Role of platelet-to-lymphocyte count ratio (PLR), as a prognostic indicator in COVID-19: A systematic review and meta-analysis

Soumya Sarkar  1 , Sundara Kannan  1 , Puneet Khanna  1 , Akhil Kant Singh  1
Affiliations
Meta-Analysis

Role of platelet-to-lymphocyte count ratio (PLR), as a prognostic indicator in COVID-19: A systematic review and meta-analysis

Soumya Sarkar et al. J Med Virol. 2022 Jan.

Abstract

Prognostic predictors are of paramount interest for prompt intervention and optimal utilization of the healthcare system in the ongoing context of the COVID-19 pandemic. The platelet-to-lymphocyte count ratio (PLR), has emerged as a potential tool for risk stratification of critically ill patients with sepsis. The current systematic review explores the utility of PLR as a prognostic predictor of COVID-19 patients. We screened the electronic databases until May 15, 2021 after enrolling in PROSPERO (CRD42021220269). Studies evaluating the association between PLR on admission and outcomes in terms of mortality and severity among COVID-19 patients were included. We retrieved 32 studies, with a total of 2768 and 3262 COVID-19 patients for mortality and disease severity outcomes. Deceased and critically ill patients had higher PLR levels on admission in comparison to survivors and non-severe patients (mean differences [MD] = 66.10; 95% confidence interval [CI]: 47.75-84.44; p < 0.00001 and MD = 86.74; 95% CI: 67.7-105.7; p < 0.00001, respectively). A higher level of PLR on admission in COVID-19 patients is associated with increased morbidity and mortality. However, the evidence is of low quality and further studies regarding the cut-off value of PLR are the need of the hour.

Keywords: Coronavirus disease 2019; Platelet-lymphocyte count ratio; Severe acute respiratory syndrome coronavirus-2.

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Conflict of interest statement

The authors declare that there are no conflict of interests.

Figures

Figure 1
Figure 1
PRISMA‐2009 flow diagram
Figure 2
Figure 2
ROBINS‐I assessment for the included non‐randomized cohort studies
Figure 3
Figure 3
The impact of the baseline PLR on mortality in COVID‐19 patients. PLR, platelet‐to‐lymphocyte count ratio
Figure 4
Figure 4
(A) The impact of baseline PLR on disease severity in COVID‐19 patients. (B) The impact of baseline PLR on disease severity in COVID‐19 patients in comparison to healthy controls. (C) The impact of baseline PLR on disease severity in COVID‐19 patients in comparison to patients with Influenza. (D) The impact of baseline PLR on disease severity in COVID‐19 patients in comparison to patients with community‐acquired pneumonia (CAP). PLR, platelet‐to‐lymphocyte count ratio
See this image and copyright information in PMC

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