Pitfalls of “hyper”-IgM syndrome: a new CD40 ligand mutation in the presence of low IgM levels. A case report and a critical review of the literature
- 28 October 2010
- journal article
- case report
- Published by Springer Science and Business Media LLC in Infection
- Vol. 38 (6), 491-496
- https://doi.org/10.1007/s15010-010-0061-9
Abstract
Here, we report on a male infant with low serum IgG, IgA and IgM levels who suffered from Pneumocystis jirovecii and cytomegalovirus (CMV) pneumonia. The patient was tested to be HIV-negative. Absolute and relative numbers of lymphocyte subsets were normal, excluding the diagnosis of an X-linked agammaglobulinaemia (Bruton’s disease). Despite the decreased serum IgM level, an X-linked hyper-IgM syndrome (X-HIGM) was considered. X-HIGM is a rare immunodeficiency usually characterised by recurrent severe opportunistic infections, low serum IgG and IgA, but normal or increased serum IgM. The syndrome is caused by mutations of the CD40 ligand (CD40L) gene. In our patient, CD40L mutation analysis proved a novel mutation at codon 257 associated with non-detectable expression of CD40L on the surface of activated T cells. A literature search revealed that approximately 6.4% of X-HIGM patients had been found to have low serum IgM levels. Our statistical analysis of the IgM levels as reported by different studies arouses suspicion that many patients with low IgM levels may not have undergone diagnostic procedures for X-HIGM. In summary, in this report and critical review of the literature, we described a new mutation of CD40L and highlighted the pitfalls of the diagnosis of X-HIGM.Keywords
This publication has 41 references indexed in Scilit:
- Molecular Characterization of Patients with X-linked Hyper-IgM Syndrome: Description of Two NovelCD40LMutationsScandinavian Journal of Immunology, 2009
- Hyper-IgM syndrome in a boy with recurrent pneumonia and hepatosplenomegalySrpski arhiv za celokupno lekarstvo, 2009
- Immunodeficiency mutation databases (IDbases)Human Mutation, 2006
- Immunological and genetic analysis of 65 patients with a clinical suspicion of X linked hyper-IgMMolecular Pathology, 2003
- Hyper IgM syndrome: the other side of the coinCurrent Opinion in Pediatrics, 2001
- Clinical spectrum of X-linked hyper-IgM syndromeThe Journal of Pediatrics, 1997
- A boy with X-linked hyper-IgM syndrome and natural killer cell deficiencyClinical and Experimental Immunology, 1997
- CD40 ligand deficiency presenting as unresponsive neutropenia.Archives of Disease in Childhood, 1996
- The role of gp39 (CD40L) in immunityClinical Immunology and Immunopathology, 1995
- CD40 ligand mutations in X-linked immunodeficiency with hyper-IgMNature, 1993