Pneumonia in children is common and can lead to grave consequences if not addressed in a proper and timely manner. In the management of pneumonia, early identification of the causative infective agent is of obvious importance for treatment, as it allows selection of the appropriate antibiotics. However, such identification requires laboratory test results, which may not be immediately available. The aim of this study was to evaluate the accuracy and usefulness of 13 markers in differentiating between viral and bacterial pneumonia in Han children (34 healthy controls and 78 patients). It was found that WBC counts were more accurate in diagnosis of the type of agent responsible for infection than was the degree of expression of HMGB1. Among the 13 markers investigated, HMGB1 was the best at discriminating between co-infected (bacterium and virus) and single-infected (bacterium or virus) children with bronchial pneumonia. HMGB1 expression of less than 1.0256, excluded most coinfections (the negative predictive value was greater than 89.7%). Diagnosed sole viral pneumonia clinically overlapped with bacterial pneumonia, but bacterial pneumonia was more often associated with higher white blood cell (WBC) counts (WBC ≥ 13,000 cells/mm 3 ). When the two marker readouts-HMGB1 < 1.0256 and WBC ≥ 13,000 cells/mm 3 -were combined, the positive predictive value for bacterial pneumonia alone was 92.3%. These findings can help clinicians discriminate between bronchial pneumonia caused by virus, bacterium or both with a high specificity.Key words bronchial pneumonia, Han children, high-mobility group box 1 protein, white blood cell.Bronchial pneumonia, a pulmonary infection causing inflammation and difficulty in breathing, can be caused by a variety of microorganisms, including viruses, bacteria, fungi, mycoplasma, and parasites. The causes of pediatric pneumonia vary greatly according to age and other risk factors (1-3). Viral pathogens are particularly important

Abstract Background The outbreak of the novel coronavirus SARSCoV-2 (coronavirus disease 2019; COVID-19) has spread to most of countries in the world. The tight relationship of plasma lipids and COVID-19 pneumonia (NCIP-19) has not been well invested. To observe lipid profiles and their alterations in hospitalized patients with COVID-19 and evaluated the prognostic value of lipids for the length of hospital stay (LOS). Methods 248 NCIP-19 cases aged 18 years or older were enrolled in this study. Serum lipids, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were detected at admission. In 68 severe cases, levels of serum lipids were subsequently detected every 5 ~ 10 days. Results At admission, median levels of TG, TC, HDL-C, and LDL-C in all patients, were 1.11 mmol/L, 4.00 mmol/L, 0.89 mmol/L and 2.11 mmol/L, respectively. Compared with common cases (n = 174), higher TG and HDL-C, lower LDL-C were observed in severe cases (n = 74). Levels of TC and LDL-C at admission were negatively correlated with LOS. In severe cases, the average levels of serum lipids were lowest at admission and gradually increased during hospitalization. Compared with the LOS ≤ 29d group, serum levels of TC, HDL-C, and LDL-C were significantly lower in the LOS > 29d group at admission; this lower trend always existed during the following tests for TC and LDL-C, but not for HDL-C and TG. Patients with LDL-C ≥ 1.70 mmol/L at admission showed a lower risk of LOS prolongation (adjusted HR = 0.557, 95% CI: 0.409–0.759, p < 0.001). Conclusions In NCIP-19, serum lipid levels were low at admission. Levels of TC and LDL-C at admission were negatively correlated with LOS. LDL-C < 1.7 mmol/L at admission may act as the independent predictor of LOS prolongation. In severe cases, the gradual increase of TC, LDL-C, and HDL-C during the hospitalization might indicate the gradual recovery of the disease.