Ying Liu

Objective: This study aimed to investigate the characteristics of the non-human immunodeficiency virus (HIV) pneumocystis pneumonia (PCP) via the microbial composition of Pneumocystis jirovecii pneumonia in the lower respiratory tract in infants with severe pneumonia who were hospitalized in the study’s pediatric intensive care unit (PICU). Methods: The clinical characteristics of 16 infants with non-HIV PCP (the PCP group) and 33 infants with severe pneumonia (the control group) who were hospitalized at the same time in the PICU were analyzed retrospectively. Using metagenomic next-generation sequencing (mNGS), the bronchoalveolar lavage fluid (BALF) of the two groups was analyzed, and the microbial results and clinical data were compared. Results: Compared with the control group, the infants in the PCP group had a lower incidence of cough (25% vs 78.8%; P < 0.05), a greater history of surgery (50.0% vs 39.1%; P < 0.05), and a more significant decrease in C3, C4, and CD4/CD8 ratios (all P < 0.05). The pathogenic bacteria in the BALF included P. jirovecii, respiratory syncytial virus, cytomegalovirus (CMV), and Staphylococcus aureus. The predominance of viral infection in the PCP group was significantly higher than in the control group (P < 0.05), especially CMV (43.5% vs 15.2%; P < 0.05). The top five symbiotic microorganisms detected in the BALF of the 49 infants were Streptococcus, Propionibacterium, Rothia, Staphylococcus, and Moraxella. There was no significant difference in the relative abundance of common symbiotic microorganisms between the two groups (all P > 0.05). Conclusion: Non-HIV PCP has a higher incidence in PICU infants with severe pneumonia, especially those with underlying diseases or who are immunocompromised, which are clinically difficult to treat. A BALF analysis using mNGS is helpful for early and clear diagnoses. It also helps to clarify the distribution of pathogenic and lower respiratory tract colonizing bacteria in infants with severe pneumonia.

Background: N-terminal pro-B-type natriuretic peptide (NTproBNP) appears to be a useful tool for diagnosing hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. However, a consensus for its application has not been reached. Objective: The present study aims to evaluate the role of NTproBNP in predicting hsPDA in preterm infants, and explore the optimal cutoff value and testing-time. Methods: A prospective blind study of 120 preterm infants with birth weights of < 1,500 g was conducted at the NICU of Peking University Shenzhen Hospital. Blood samples were successively collected on the first three days after birth for NTproBNP analysis. Echocardiographies were performed on day three of life to confirm the status of the ductus arteriosus. A receiver operating characteristic curve (ROC) analysis was performed to determine the ability of NTproBNP to recognize hsPDA. Results: NTproBNP was significantly higher in infants with hsPDA, than in infants in the control group, on both day two (P < 0.001) and day three (P < 0.001). On day two, a NTproBNP cutoff value of 3,689.0 pmol/L offered an optimal predictive value for hsPDA, while on day three, the optimal cut-off value for hsPDA was 2,331.5 pmol/L. The investigators proposes day three of life (48–72 hours) as the optimal testing time. Conclusion: The NTproBNP biomarker during the early neonatal period can be a useful tool for screening and assessing hsPDA in premature infants, especially on day three of life.