Value of Laboratory Indicators in Predicting Pneumonia in Symptomatic COVID-19 Patients Infected with the SARS-CoV-2 Omicron Variant

BACKGROUND: The pathogenicity of Omicron is different from that of the previous strains. The value of hematological indicators in patients at high risk of Omicron infection remains unclear. We need rapid, inexpensive and widely available biomarkers to guide the early detection of people at risk of pneumonia and to provide early intervention. We aimed to assess the value of hematological indicators as risk factors for pneumonia in symptomatic COVID-19 patients infected with the SARS-CoV-2 Omicron variant. PATIENTS AND METHODS: The study enrolled 144 symptomatic COVID-19 patients with Omicron infection. We collected available clinical details, including laboratory tests and CT examinations. Univariate and multivariate logistic analyses and receiver operating characteristic (ROC) curve analyses were used to assess the value of laboratory markers in predicting the development of pneumonia. RESULTS: Among the 144 patients, 50 (34.7%) had pneumonia. The ROC analysis revealed that the areas under the ROC curve (AUC) for leukocytes, lymphocytes, neutrophils, and fibrinogen were 0.603 (95% confidence interval (CI): 0.501–0.704, P=0.043), 0.615 (95% CI: 0.517–0.712, P=0.024), 0.632 (95% CI: 0.534–0.730, P=0.009) and 0.635 (95% CI: 0.539–0.730, P=0.008), respectively. The AUC for neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), fibrinogen to lymphocyte ratio (FLR), and fibrinogen to D-dimer ratio (FDR) were 0.670 (95% CI: 0.580–0.760, P=0.001), 0.632 (95% CI: 0.535–0.728, P=0.009), 0.669 (95% CI: 0.575–0.763, P=0.001) and 0.615 (95% CI: 0.510–0.721, P=0.023), respectively. Univariate analysis showed that elevated levels of NLR (odds ratio (OR): 1.219, 95% CI: 1.046–1.421, P=0.011), FLR (OR: 1.170, 95% CI: 1.014–1.349, P=0.031) and FDR (OR: 1.131, 95% CI: 1.039–1.231, P=0.005) were significantly correlated with the presence of pneumonia. Multivariate analysis indicated elevated NLR (OR: 1.248, 95% CI: 1.068–1.459, P=0.005) and FDR (OR: 1.160, 95% CI: 1.054–1.276, P=0.002) levels were associated with the existence of pneumonia. The AUC for the combination of NLR and FDR was 0.701 (95% CI: 0.606–0.796, P<0.001, sensitivity 56.0%, specificity 83.0%). CONCLUSION: NLR and FDR can predict the presence of pneumonia in symptomatic COVID-19 patients infected with the SARS-CoV-2 Omicron variant.