Severe COVID-19 patients have more neutrophils, higher neutrophil-to-lymphocyte ratio level and fewer lymphocytes

Objectives:
The ongoing worldwide pandemic of Coronavirus Disease 2019 (COVID-19) has posed a huge threat to global public health. However, whether routine blood test could be used to monitor and predict the severity and prognosis of COVID-19 has never been comprehensively investigated. Therefore, this review article has been conducted.

Which markers in routine blood test are associated with the severity of COVID-19?

Study design:
This review article included 15 studies with 3,090 COVID-19 patients.

Results and conclusions:   
The investigators found patients in non-severe COVID-19 group had fewer white blood cells [WMD = -0.85 [109/L], 95% CI = -1.54 to -0.16, p = 0.02] and neutrophils [WMD = -1.57 [109/L], 95% CI = -2.60 to -0.54, p = 0.003], more lymphocytes [WMD = 0.29 [109/L], 95% CI = 0.22 to 0.36, p  0.001] and platelets [WMD = 19.05 [109/L], 95% CI = 3.04 to 35.06, p = 0.02] and lower neutrophil-to-lymphocyte ratio (NLR) level [WMD = -2.48, 95% CI = -3.81 to -1.15, p  0.001], compared with those in severe COVID-19 group.

The investigators found, however, there was no statistical difference in monocytes [WMD = 0.01 [109/L], 95% CI = -0.01 to 0.03, p = 0.029] between these two groups.

The investigators found sensitivity analysis and meta-analysis based on standard mean difference (SMD) did not change the conclusions about neutrophils, lymphocytes and neutrophil-to-lymphocyte ratio, while the results were inconsistent in white blood cells and platelets.

The investigators concluded severe COVID-19 patients have more neutrophils, higher neutrophil-to-lymphocyte ratio level and fewer lymphocytes than non-severe patients with COVID-19. Measurement of these markers might assist clinicians to monitor and predict the severity and prognosis of COVID-19.

Original title:
Can we predict the severity of COVID-19 with a routine blood test? By Zeng F, Li L, […], Deng G.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32356642

Additional information of El Mondo:
Find more information/studies on coronavirus right here.