X-linked hyper-IgM syndrome with CD40LG mutation presents with pediatric
respiratory tract infection
Abstract
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.