Growth hormone deficiency (GHD) may be associated with a number of immunodeficiency diseases, but its association with immunoglobulin class switch recombination (Ig CSR) deficiencies is very rare. We report the case of a patient with a history of recurrent diarrhea and respiratory infections diagnosed with hyper IgM syndrome on the basis of immunological findings (low serum levels of IgG and Ig...

Understanding how class switch recombination (CSR) is regulated to produce immunoglobulin E (IgE) has become fundamental because of the dramatic increase in the prevalence of IgE-mediated hypersensitivity reactions. CSR requires the induction of the enzyme AICDA in B cells. Mutations in AICDA have been linked to Hyper-IgM syndrome (HIGM2), which shows absence of switching to IgE as well as to I...

Evidence is presented for the existence of a "switch" T cell derived from a patient with mycosis fungoides/Sezary's syndrome. The serum immunoglobulin profile in this patient revealed high IgG and IgA but no detectable IgM. Peripheral blood mononuclear cells from this patient secreted only IgG and IgA in the presence of pokeweed mitogen. T cells (Trac) co-cultured with normal allogeneic non-T c...

Induced overexpression of AID in CH12F3-2 B lymphoma cells augmented class switching from IgM to IgA without cytokine stimulation. AID deficiency caused a complete defect in class switching and showed a hyper-IgM phenotype with enlarged germinal centers containing strongly activated B cells before or after immunization. AID-/- spleen cells stimulated in vitro with LPS and cytokines failed to un...

hyper-igm syndromes are characterized by profound reduction of serum igg, iga, and ige levels with normal or increased concentrations of serum igm. cd40 ligand deficiency is x-linked form of the disease, which results in a lack of immunoglobulin class switching from igm to igg in b cells. in addition to the recurrent infections, a number of patients suffer from neutropenia. there are some evide...

BACKGROUND Despite considerable effort, the genetic factors responsible for >90% of the antibody deficiency syndromes IgAD and CVID remain elusive. To produce a functionally diverse antibody repertoire B lymphocytes undergo class switch recombination. This process is initiated by AID-catalyzed deamination of cytidine to uridine in switch region DNA. Subsequently, these residues are recognized b...

X-linked hyper-IgM syndrome (XHM) is a combined immune deficiency disorder caused by mutations in CD40 ligand. We tested CP-870,893, a human CD40 agonist monoclonal antibody, in the treatment of two XHM patients with biliary Cryptosporidiosis. CP-870,893 activated B cells and APCs in vitro, restoring class switch recombination in XHM B cells and inducing cytokine secretion by monocytes. CP-870,...

Hyper-IgM syndrome (HIGM) is a heterogeneous condition characterized by impaired Ig class-switch recombination (CSR). The molecular defects that have so far been associated with this syndrome - which affect the CD40 ligand in HIGM type 1 (HIGM1), CD40 in HIGM3, and activation-induced cytidine deaminase (AID) in HIGM2 - do not account for all cases. We investigated the clinical and immunological...

Immunoglobulin class switch recombination deficiencies (Ig CSR deficiencies) or Hyper IgM syndromes (HIGM) are a group of primary immunodeficiency diseases, characterized by defective CD40 signaling of B cells, resulting in reduced CSR and somatic hypermutation. The affected patients are characterized by low serum levels of IgG and IgA, and normal or elevated levels of IgM, which lead to an inc...

INDIAN PEDIATRICS 952 VOLUME 42__SEPTEMBER 17, 2005 Hyper IgM syndrome (HIGM) is a rare primary immunodeficiency characterized by low levels of serum IgA and IgG and a normal or increased levels of IgM due to a block in the B cell immunoglobulin switch from IgM to IgG(1). The estimated incidence is approximately 1 in 10,30,000 live births(2). Two types are described X linked hyper IgM (XHIM) an...