Biomedical
Complete blood count alterations in COVID-19 patients
Mariangela Palladino
Peer Reviewed
Doi: http://dx.doi.org/10.11613/bm.2021.030501
Abstract
Coronavirus disease 2019 (COVID-19) pandemic represents a scientific and social crisis. One of the main unmet needs for coronavirus disease 2019 is its unpredictable clinical course, which can rapidly change in an irreversible outcome. COVID-19 patients can be classified into mild, moderate, and severe. Several haematological parameters, such as platelets, white blood cell total count, lymphocytes, neutrophils, (together with neutrophil-lymphocyte and platelet-lymphocyte ratio), and haemoglobin were described to be associated with COVID-19 infection and severity. The purpose of these review is to describe the current state of the art about complete blood count alterations during COVID-19 infection, and to summarize the crucial role of some haematological parameters during the course of the disease. Decreased platelet, lymphocyte, haemoglobin, eosinophil, and basophil count, increased neutrophil count and neutrophil-lymphocyte and platelet-lymphocyte ratio have been associated with COVID-19 infection and a worse clinical outcome. Our study adds some novelty about the identification of effective biomarkers of progressive disease, and might be helpful for diagnosis, prevention of complications, and effective therapy.
Key Questions
What changes in complete blood count (CBC) are commonly observed in COVID-19 patients?
COVID-19 patients often exhibit alterations such as decreased platelet count, lymphopenia (reduced lymphocyte count), and elevated neutrophil count. Additionally, changes in the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are noted, which correlate with disease severity.
Why is lymphopenia significant in COVID-19?
Lymphopenia is significant because it is a common finding in severe COVID-19 cases and reflects the immune dysregulation caused by the virus. It is also a potential marker for disease severity.
How does the neutrophil-lymphocyte ratio (NLR) relate to COVID-19 prognosis?
Elevated NLR is associated with more severe disease and worse clinical outcomes. It serves as a useful biomarker for identifying high-risk patients.
Are platelet count alterations observed in COVID-19 patients?
Yes, a decreased platelet count is commonly observed in COVID-19 patients and is linked to severe disease. Platelet count monitoring is critical in evaluating disease progression.
What role does hemoglobin play in COVID-19 assessment?
Reduced hemoglobin levels, indicating anemia, have been reported in COVID-19 patients. This alteration may reflect the systemic inflammatory response and should be considered in clinical assessments.
Why is the platelet-lymphocyte ratio (PLR) relevant in COVID-19?
Higher PLR has been associated with adverse outcomes in COVID-19 patients. It is a potential marker for inflammation and disease severity.
What is the clinical significance of eosinophil and basophil counts in COVID-19?
Both eosinophil and basophil counts are often reduced during COVID-19 infection. These changes are part of the immune response to the virus and may serve as additional markers for disease activity.
Doi: http://dx.doi.org/10.11613/bm.2021.030501