Predictive values of neutrophil-to-lymphocyte ratio on disease severity and mortality in COVID-19 patients: a systematic review and meta-analysis

Abstract

Background Coronavirus disease 2019 (COVID-19), a highly infectious disease, has been rapidly spreading all over the world and remains a great threat to global public health. Patients diagnosed with severe or critical cases have a poor prognosis. Hence, it is crucial for us to identify potentially severe or critical cases early and give timely treatments for targeted patients. In the clinical practice of treating patients with COVID-19, we have observed that the neutrophil-to-lymphocyte ratio (NLR) of severe patients is higher than that in mild patients. We performed this systematic review and meta-analysis to evaluate the predictive values of NLR on disease severity and mortality in patients with COVID-19. Methods We searched PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and Wanfang databases to identify eligible studies (up to August 11, 2020). Two authors independently screened studies and extracted data. The methodological quality of the included studies was assessed by Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Results Thirteen studies involving 1579 patients reported the predictive value of NLR on disease severity. The pooled sensitivity (SEN), specificity (SPE) and area under curve (AUC) were 0.78 (95% CI 0.70–0.84), 0.78 (95% CI 0.73–0.83) and 0.85 (95% CI 0.81–0.88), respectively. Ten studies involving 2967 patients reported the predictive value of NLR on mortality. The pooled SEN, SPE and AUC were 0.83 (95% CI 0.75–0.89), 0.83 (95% CI 0.74–0.89) and 0.90 (95% CI 0.87–0.92), respectively. Conclusions NLR has good predictive values on disease severity and mortality in patients with COVID-19 infection. Evaluating NLR can help clinicians identify potentially severe cases early, conduct early triage and initiate effective management in time, which may reduce the overall mortality of COVID-19. Trial registry This meta-analysis was prospectively registered on PROSPERO database (Registration number: CRD42020203612).

High dimensional profiling identifies specific immune types along the recovery trajectories of critically ill COVID19 patients

“…This results in a higher neutrophil-to-lymphocyte ratio, which was also identified as an early prognostic marker for severe disease [ 16 , 52 ]. Meta-analyses have confirmed the utility of this ratio not only as a measure of disease severity [ 53 , 54 ], but also as a predictor of mortality [ 55 ]. Importantly, the NLR had a significantly higher adjusted odds ratio than cell counts alone, CRP, lymphocyte-to-monocyte ratio, or platelet-to-lymphocyte ratio [ 18 ], thus highlighting the benefit of this ratio over other comparative leukocyte ratios or routinely measured laboratory parameters.…”

Laboratory biomarkers of COVID-19 disease severity and outcome: Findings from a developing country

“…Different laboratory markers are implicated as an indicator of disease severity, progression and outcome. Deranged cell counts, like anemia, polycythemia, leukopenia and leukocytosis with neutrophil predominance and decreased platelet count are found to be associated with severe disease and worse outcome in hospitalized patients [2][3][4][5][6][7][8][9]. Similarly raised liver enzymes and total bilirubin levels were identified in severe and critical patients [6,[10][11][12][13][14][15].…”

The systemic inflammatory response and clinicopathological characteristics in patients admitted to hospital with COVID-19 infection: Comparison of 2 consecutive cohorts

“…In particular, the 4C mortality score was developed in more than 55,000 patients with COVID-19 and measured the systemic inflammatory response using C-reactive protein (6). Other measures of the systemic inflammatory response such as the neutrophil lymphocyte ratio (NLR) have also been shown to have prognostic value (7). Moreover, the systemic inflammatory response has been shown to be a useful therapeutic target in patients with COVID-19 (8)(9)(10).…”