Primary Immunodeficiencies: Antibody Deficiency and Immunoglobulin Replacement Therapy

Primary immunodeficiencies occur with a frequency approaching that of cystic fibrosis (1:2500 live births). However, because they are perceived to be very rare and usually present with common infections, they are under-diagnosed. Often the diagnosis is not considered until substantial end-organ damage has occurred, by which time definitive treatment is only partially successful in preventing further infections. (more…)

SAP Gene Defects In Male Patients Diagnosed With Common Variable Immunodeficiency

The molecular basis of Common Variable Immunodeficiency (CVID) is unknown and the diagnosis requires the exclusion of other diseases known to cause primary antibody deficiency syndromes, such as X-linked lymphoproliferative disease (XLP). XLP is a rare primary immunodeficiency disease in which severe immune dysregulatory phenomena occur, typically after exposure to Epstein–Barr virus (EBV). The defective gene in XLP is SAP (SLAM associated protein, where SLAM is signalling lymphocyte activation molecule), a small SH2 domain containing protein involved in signal transduction events downstream of the SLAM family of receptors. (more…)

Common Variable Immunodeficiency: ICOS Deficiency In Patients With CVID Diagnosis

Common Variable Immunodeficiency (CVID) is the most frequent primary immunodeficiency in man that requires medical intervention. Most cases are sporadic, but about 10% are familial, with a predominance of autosomal dominant over autosomal recessive inheritance. It has recently been shown that homozygous loss of the inducible costimulator (ICOS) on activated T cells may result in an adult form of CVID with autosomal recessive inheritance. ICOS belongs to the family of costimulatory T-cell molecules such as CD28 and CTLA-4. (more…)