An emerging marker predicting the severity of COVID-19: Neutrophil-Lymphocyte Count Ratio

Abstract

Background: To analyze clinical features and laboratory indicators and identify the markers of exacerbation in COVID-19. Methods: We reviewed clinical histories of 177 patients with confirmed COVID-19. The patients were categorized into mild group (153 patients) and severe group (24 patients). The baseline demographic and laboratory indicators of all patients were collected, including the neutrophil-lymphocyte count ratio (NLCR) and C-reactive protein to albumin ratio (CAR). Receiver operating characteristic curve (ROC) analysis was performed to search for indicators predicting exacerbation in COVID-19 patients, and acquiring the area under the curves (AUCs), sensitivity, specificity and cut-off value. Results: The age of the severe group were significantly older than those of the mild group (P <0.01). Fever was the typical symptom in all COVID-19 patients. Cough and fatigue were manifested in mild group, yet severe patients were more prominent in dyspnea. The laboratory indicators showing that the mild group mainly had an elevated C-reactive protein; the severe group had a decreased lymphocyte count and lymphocyte ratio. WBC, neutrophil count, neutrophil ratio, D-dimer, AST, ALT, LDH, BUN, CRP levels increased. Furthermore, compared to mild group, WBC, neutrophil count, neutrophil ratio (Neut%), D-dimer, total bilirubin, albumin, AST, ALT, LDH, BUN, creatine kinase, CRP, CAR, NLCR were significantly higher, the lymphocyte count, lymphocyte ratio, and APTT were significantly lower in severe group (P<0.05). The ROC indicating that NLCR, Neut%, CAR, CRP, and LDH were better at distinguishing mild and severe patients. The AUCs of NLCR was larger than others (NLCR>Neut%>CAR>CRP>LDH: 0.939>0.925>0.908>0.895>0.873), which suggested that NLCR was the optimal maker; a cut-off value for NLCR of 6.15 had 87.5% sensitivity and 97.6% specificity for predicting exacerbation in COVID-19 patients. Conclusions: The different types of COVID-19 had significant differences in age, clinical symptoms and laboratory indicators, and severe patients might be easier to suffer from the multiple organ damage. An elevated NLCR may indicate that the disease was progressing towards exacerbation. It was essential to dynamically monitor the serum NLCR levels which contributed to evaluate the patient's condition and efficacy. NLCR could be used as a novel, highly specific and sensitive marker for predicting severity of COVID-19 patients.

C-reactive Protein, Albumin, Urea, CRP/Albumin Ratio, and Urea/Albumin Ratio: A Retrospective Evaluation in COVID-19 Patients

“…However, in patients with severe to critical COVID-19, albumin levels decreased significantly on days five to (27,28,29). Our cut-off is also found to be higher than other studies, ranging from 0.73 to 0.9 (27,30,31).…”

Screening role of complete blood cell count indices and C reactive protein in patients who are symptomatic for COVID-19

“…Zhang et al [1] in Hunan, China, by examining 177 patients (99 men and 78 women) with a definitive diagnosis of COVID-19 and dividing them into mild groups with 153 patients and severe patients with 24 patients, found that the laboratory parameters, albumin, total bilirubin, WBC, neutrophil count, neutrophil ratio, D-dimer, aspartate transaminase (AST), alanine transaminase (ALT), LDH, blood urea nitrogen (BUN), creatine kinase (CK), CRP, and CRP to albumin ratio (CAR), in the severe group had a significant increase. lymphocyte count and lymphocyte ratio tests have a significant decrease compared with the mild group, and they showed that high NLR could be a sign of disease progression to a serious condition and also NLR could be used as a very specific and sensitive indicator to predict the severity of the disease.…”

“…The definitive treatment for severe cases is not available and different treatment models, as well as its diagnostic methods, are still in the research stages [7]. Therefore, early diagnosis and identification of patients can be of great help in improving and preventing the disease from entering the respiratory phase and reducing mortality, improving the speed of treatment, and also preventing the spread of the disease [1].…”

Neutrophils at the crossroads of acute viral infections and severity

“…Distinct populations of ARG+ and PD-L1+ neutrophils were present in COVID patients, which directly correlated with increasing severity ( Schulte-Schrepping et al, 2020 ). Lymphopenia is observed in SARS-CoV-2 infected patients ( Chen et al, 2020 ; J. jin Zhang et al, 2020 , Zhang et al, 2020 ) and the severe group had decreased lymphocyte count than the non-severe group ( Diao et al, 2020 ; Schulte-Schrepping et al, 2020 ). However, the mechanisms of lymphocyte reduction in severe patients remain unclear.…”