Hyper-IgM syndrome (HIM) is a rare disorder resulting from mutation in the CD40 ligand (CD40L) gene. This defect is associated with normal or elevated serum level of IgM and with low to undetectable levels of serum IgG, IgA, IgE. This case of HIM with CD40L deficiency was proven by flow cytometry but initially presented as interstitial pneumonia. Pneumocystis carinii pneumonia was highly sugges...

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...

Background: Defects in B cell class switch recombination (CSR) are a heterogeneous and yet very uncommon group of disorders which all have a genetic basis uniformly leading to hyper IgM (HIgM) syndrome. Due to the rare frequency of these conditions, a very small number of case series have been conducted on the affected patients. Objective: To shed some light on the morbidity and mortality regar...

The molecular basis of common variable immunodeficiency (CVID) is unknown. To assess humoral immunity in CVID, we selected 24 patients with early or late onset of disease. X-linked agammaglobulinemia (XLA), X-linked hyper-IgM syndrome (XHIM), and non-XHIM were excluded based on clinical phenotype, assessment of the immune response, presence of Bruton's tyrosine kinase (Btk) in monocytes or plat...

Abstmcr-Most second-order RC active filters show II marked dependence on tbe gdn-bnndwidtb product (GB) of operational aniplifietx (OA’s) when the w, to be reali& is greater than 1 percent of GB and Q> 10. Here designs are given that are. virtually independent of OA’s when we<O.Ol GB and Q< 10. Even for w0=0.05 GB and Q=lO, the center frequency shift due to OA’s is less than 0.1 percent. ‘Ihis ...