Sherif Abuserewa, MD, M.Sc.
Internal medicine resident
Grand Strand Regional Medical Center
Myrtle Beach, SC
Disclosure information not submitted.
Eric Shaw, PhD
Professor
Mercer University School of Medicine, United States
Disclosure information not submitted.
Leslie Hart
Research Analyst, Graduate Medical Education
HCA | Physician Services Group, United States
Disclosure information not submitted.
Cari Jennings
Research Analyst, Graduate Medical Education
HCA | Physician Services Group, United States
Disclosure information not submitted.
Richard Duff, MD
Pulmonary and Critical Care physician
Grand Strand Regional Medical Center, South Carolina, United States
Disclosure information not submitted.
Title: Role of Neutrophil to Lymphocyte Ratio in Diagnosis and Prognosis of Severe COVID Infection
Introduction: Several Studies on COVID-19 infection diagnosis and prognosis were done, but Neither of Them was Able to Sharply Predict Who of the Patients will Deteriorate and Develop Severe infection. Few Small Sample Sized Retrospective Studies were Done in China on Neutrophil to Lymphocyte Ratio (NLR) as an Inflammatory Marker in COVID Patients. Given the Racial and Genetic Differences from US Population, a Large Scale Retrospective Study was Held to Provide New Correlations between NLR and COVID-19 Infection.
Methods: A Retrospective Cohort Study with Analysis of Electronic Medical Records of 2,228 COVID-19 Patients Confirmed with Nasopharyngeal Swab PCR. The Patients were Divided into Two Groups; Moderate/Non-Severe Group and Severe/Critical Group. Severe Illness from COVID-19 was Defined as Admission to the ICU, Intubation or Mechanical Ventilation, or Death. CBC with Differential Count was Collected and NLR was Calculated. Normal Range of NLR is Roughly 1-3. A NLR of 6 to less than 9 Suggests Mild Stress While Critically Ill Patients Will Often Have an NLR of 9 or Higher. Blood Samples were Collected on the Day of Admission Before Starting Steroids. All Factors that may Affect NLR Including Use of Systemic Steroids, Inflammatory Diseases, Malignancy, and Immunocompromised State were all Excluded.
Results: Of the 511 Patients Who had Severe COVID-19, They Had a Mean NLR of 10.1655. Of the 1716 Patients Who Did Not Have Severe COVID-19, Their Mean NLR was 6.0295. Of the 406 Patients Who were Admitted to ICU, They had a Mean NLR of 10.3398. Of the 1821 Patients not Admitted to the ICU, Their Mean NLR was 6.2291. Of the 169 Patients who Expired, They had a Mean NLR of 10.9489. Of the 2058 Patients Who Did Not Expire, Their Mean NLR was 6.6525. Of the 376 Patients Who were on a Ventilator, They had a Mean NLR of 10.1278. Of the 1851 Patients not on a Ventilator, Their Mean NLR was 6.3388.
The Mean NLR Difference between Those with Severe COVID-19 Versus without Severe COVID-19, Those Admitted to ICU Versus Not Admitted, Those on Ventilator Versus not on Ventilator, Those Who Expired versus Who Did Not Expire are all Statistically Significant (p=.000).
Conclusions: NLR is an Inflammatory Marker that can be a Useful Predictor for Severe COVID-19 Infection at the Initial Encounter with COVID-19 Patients.