CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics

A novel CD40LG mutation causing X‑linked hyper-IgM syndrome

X-linked hyper-IgM (X-HIGM), which results from mutations of the CD40 ligand gene (CD40LG) located on chromosome Xq26.3, is characterized by a defective T-B lymphocyte cross talk and class switch recombination (CSR). The present study aimed to evaluate the expression of CD40L and lymphocyte subsets using flow cytometry and to identify the novel genetic defect of CD40LG responsible for X-HIGM in a Chinese family. We reported an X-HIGM case caused by a novel mutation in CD40LG. The expression of CD40L was absent on the surface of activated CD4 + T cells evaluated using flow cytometry. The total number of mature B cells in circulation was normal, but memory B cells were significantly decreased. In helper T cells, Th2 was dominant, and the numbers of Th1 and Th17 were decreased. The results of genetic analysis revealed a new causative mutation in CD40L (NM_000074;exon5;c.505_506del), which leads to a change in amino acids (p.Y169Lfs*31) appearing in the proband. The frame shift mutation led to incorrect amino acid translation and loss of β-pleated sheet and loop region, which produced a mutant dysfunctional protein. This study provides a complete picture of X-HIGM and broadens our knowledge of the pathogenicity of the CD40L variant spectrum.

Diagnostic value of sTREM-1, sCD25, sCD40L and sCD130 in late-onset neonatal sepsis

INTRODUCTION

Neonatal sepsis represents a major public health challenge worldwide, presenting serious risks to the health and survival of infants. The identification of novel and efficient serum biomarkers to replace traditional blood cultures is critical for the timely diagnosis and management of this condition. Our objective is to evaluate the diagnostic value of sTREM-1, sCD25, sCD40L, and sCD130 in cases of late-onset neonatal sepsis.

METHODS

This prospective case-control study comprised 80 infants, 40 suspected of having LOS and 40 serving as the control group. Venous anticoagulated blood was collected to measure sTREM-1, sCD25,sCD40L,sCD130, CRP, and PCT levels.

RESULTS

The LOS group exhibited a notably higher occurrence of premature labor, low birth weight, chorioamnionitis, and longer inpatient stays compared to the control group(P < 0.05). CRP, PCT, sTREM-1, and sCD130 were identified as independent predictors of LOS. At the sTREM-1 cutoff value of 42.64 pg/ml, the sensitivity and specificity were 93.20 % and 89.70 %, respectively; at the sCD130 cutoff value of 131165.85 pg/ml, the sensitivity was 91.40 %, and the specificity was 86.20 %. Furthermore, CRP and PCT demonstrated a positive correlation with serum sTREM-1, whereas sCD130 exhibited a negative correlation with both CRP and PCT.

CONCLUSION

Compared to conventional markers,sTREM-1 and sCD130 exhibit higher sensitivity and specificity, making them reliable indicators for diagnosing LOS.

The Latin American Society for Immunodeficiencies Registry

Purpose - The Latin American Society of Immunodeficiencies (LASID) Registry was established in 2009 to collect data on Inborn Errors of Immunity (IEI) patients in the region. Although several reports have been published regarding LASID data, this is the first report of the entire dataset. Methods - The European Society of Immunodeficiencies (ESID) donated the online platform in 2008. Data was collected from participating centers from Apr 13, 2009, to Dec 31, 2022, and included demographic, clinical, and follow-up information. Results - A total of 9307 patients were included in the database. At the end of the study period, 8,805 patients were alive or lost to follow-up, and 502 were deceased. The most common type of IEI was predominantly antibody deficiency (PAD, 60.35%), and selective IgA deficiency was the most frequent diagnosis (1627 patients, 17.48%), followed by Common Variable Immune Deficiency (CVID, 1191 patients). Most patients (78.16%) were ≤ 18 years old at inclusion, and the median age at diagnosis was 4.77 years. The median time to diagnosis was 5.04 years. Antibiotics were prescribed in 32.3% of visits, followed by immunoglobulins (29.49% ). Hematopoietic stem cell transplantation was performed in 5.03% of patients. Omenn syndrome was the most common disease in deceased patients, with a mortality rate of 52.63%. Conclusion - This study contributes to our understanding of IEIs in Latin America and highlights the importance of early diagnosis, appropriate treatments, and improved data collection to optimize patient outcome.

Respiratory infections in X-linked hyper-IgM syndrome with CD40LG mutation: a case series of seven children in China

BACKGROUND

X-linked hyper-immunoglobulin M (XHIGM), a primary immunodeficiency syndrome caused by mutations in the CD40 ligand gene(CD40LG), 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

There were seven boys with age ranging from 4-20 months (median age, 13 months). Four of the seven respiratory infections were caused by Talaromyces marneffei(T. marneffei). Two patients had viral infections caused by cytomegalovirus (CMV) and human adenovirus respectively. One patient had a mixed infection caused by Pneumocystis carinii and CMV. Except for one child who died of respiratory failure, one patient received hematopoietic stem cell transplantation (HSCT) and recovered well, the other five 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 respiratory infections usually begin within 2 years old, fungi and viruses are important pathogens causing respiratory infections in children with XHIGM. In endemic areas, T. marneffei is the common pathogen of respiratory tract infection in children with the disease.