Mortality Prognostic Hematological Parameters in COVID-19 Patients

Abstract

Background: Coronavirus disease (COVID-19) pandemic has led to a global pandemic with cases ranging from asymptomatic infection to severe acute respiratory distress syndrome (ARDS). Early in the pandemic, COVID-19 was observed to affect multiple hematological parameters including leukocytes, lymphocytes, and platelets. We conducted this study to assess possible correlation between certain parameters such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and severity of COVID-19 infection.

Methods: This is a single-center retrospective analysis of the data of adults (aged above 18 years) hospitalized at our facility from March to August 2020. All patients had the following criteria: oxygen saturation below 94% without oxygen supplementation on presentation and positive COVID-19 real-time reverse-transcriptase-polymerase chain reaction (RT-PCR).

Results: The study population was 276 patients, and 52.2% were males. Multiple comorbidities were documented. Hypertension, diabetes, and asthma were the most common. Overall mortality was 21.3%. Leukocytosis along with lymphopenia were associated with significantly increased risk for intensive care unit (ICU) admission; however only leukocytosis was associated with increased risk of mechanical ventilation and death. PLR and NLR were significantly associated with disease severity in terms of rates of ICU admission, mechanical ventilation, and death. Although lymphopenia was noted more frequently in patients with severe COVID-19 infection, the association between lymphopenia and in-hospital mortality was not statistically significant in our study. The parameters can be used to predict severity, guide patient triage and early intervention.

Conclusions: We conclude NLR and PLR can be used as simple prognostic factors to predict severity of COVID-19 patients and guide possible close monitoring and earlier intervention.

Clin Infect Immun. 2023;8(1):13-23
doi: https://doi.org/10.14740/cii159