Huifeng Fan

and 7 more

Background: X-linked hyper-immunoglobulin M (XHIGM), a primary immunodeficiency syndrome caused by mutations in the CD40 ligand gene, presents with recurrent respiratory infections in pediatric patients. We aimed to evaluate the spectrum of clinical features and respiratory pathogens in pediatric patients with XHIGM in China. Methods: We retrospectively reviewed seven pediatric patients who were diagnosed with XHIGM and received follow-up treatment at the Guangzhou Women and Children’s Medical Center between January 2010 and January 2021. We determined their clinical characteristics, causative pathogens, and prognosis by performing peripheral immunological and genetic tests. Results: The majority of respiratory infections in four of the seven patients were caused by Talaromyces marneffei. Two patients had viral infections caused by cytomegalovirus (CMV) and human adenovirus. One patient had a mixed infection caused by Pneumocystis carinii and CMV. Except for one child who died of respiratory failure, the other six patients survived with regular infusions of intravenous immunoglobulin (IVIg) during the follow-up period. Six patients had reduced antibody levels, especially IgG, IgA, and IgE levels. Increased serum IgM levels were detected in four cases, and three cases presented normal IgM levels at onset. All children were diagnosed with XHIGM with CD40LG variation. Three novel mutations were identified in the present study. Conclusions: Our study suggests that fungi and viruses are important pathogens causing respiratory infections in children with XHIGM. In endemic areas, children with T. marneffei infections have abnormal Ig levels in their peripheral blood, suggesting the ease of early gene detection in these patients.

Yun Zhu

and 18 more

Background Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in the children worldwide. In this study, we aim to describe the aetiology of viral infection of pediatric community-acquired pneumonia in mainland China. Methods During Nov. 2014 and Jun. 2016, the prospective study was conducted at thirteen hospitals. The hospitalized children under 18 years old who met the criteria for CAP were enrolled. The throat swabs or nasopharyngeal aspirates were collected from cases and screened the eighteen respiratory viruses using multiplex PCR assay. Results Viral pathogens were present in 56.6% (1539/2721) of enrolled cases, with the detection rate of single virus in 39.8% cases and multiple viruses in 16.8% cases. The most frequently detected virus was RSV (15.2%, 413/2721). The highest detection rate of virus was in < 6 m age group (70.7%). RSV, HMPV, HPIVs and Flu B showed the similar prevalence pattern both in northern and south China, but HPIVs, Flu A, HBoV, HAdV and HCoVs showed the distinct circulating patterns in northern and south China. HEV/HRV (27.6%, 27/98), HBoV (18.4%, 18/98), RSV (16.3%, 16/98) and HMPV (14.3%, 14/98) were the most commonly detected virus in severe pneumonia children with signal virus infection. Conclusions In conclusion, viral pathogens are frequently detected in pediatric CAP cases and may therefore play a vital role in the aetiology of CAP. RSV was the most important virus in hospitalized children with CAP in mainland China.