title: Evaluation of B lymphocyte deficiencies.
abstract: The most common of the primary immunodeficiency diseases are those that involve inadequate antibody production. The characteristic presentation of these disorders is recurrent sinopulmonary infections. An arrest in B cell development at the pre-B cell stage leads to agammaglobulinemia and an insignificant number of B cells. X-linked agammaglobulinemia is the most common of these developmental arrests while the autosomal recessive agammaglobulinemias comprise a small minority of the total cases. Likewise, the most common form of the hyper-IgM syndromes (CD40 ligand deficiency) is X-linked. Of the autosomal recessive forms, CD40 deficiency is basically identical to the X-linked form in its clinical phenotype where, in addition to inadequate antibody production, there is defective T cell signaling through the CD40-CD40L interaction. Aside from CD40 deficiency, the other recessive forms of hyper-IgM syndrome have adequate T cell function. IgA deficiency is the most common and the most benign of the B cell disorders. Common variable immunodeficiency is diverse in its presentation and clinical course. The pathophysiology of this disease is multifactorial and frequently ill defined, often making it a diagnosis of exclusion. A working knowledge of identifiable PIDDs is essential in both recognizing when to suspect immunodeficiency and making a diagnosis.
authors.affiliation: The Children's Foundation Research Center, and Department of Pediatrics, College of Medicine, University of Tennessee, Memphis, Tennessee, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Vickery
authors.forename: Christie F
authors.initials: CF
authors.lastname: Michael
authors.forename: D Betty
authors.initials: DB
authors.lastname: Lew
mesh_terms: D000361:Agammaglobulinemia / Q000276:immunology* / Q000473:pathology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000473:pathology*; D017074:Common Variable Immunodeficiency / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000276:immunology* / Q000473:pathology