%0 Journal Article
%T Immunophenotypic Analysis of B Lymphocytes in Patients with Common Variable Immunodeficiency: Identification of CD23 as a Useful Marker in the Definition of the Disease
%A Giuseppe Patuzzo
%A Filippo Mazzi
%A Antonio Vella
%A Riccardo Ortolani
%A Alessandro Barbieri
%A Elisa Tinazzi
%A Giacomo Marchi
%A Orazio Codella
%A Ruggero Beri
%A Antonio Puccetti
%A Claudio Lunardi
%J ISRN Immunology
%D 2013
%R 10.1155/2013/512527
%X Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by the failure of B lymphocytes differentiation leading to deficient immunoglobulins secretion. The identified genetic defects account only for a minority of cases. The importance of B cells immunophenotyping in the classification of CVID is known. This procedure can identify alterations on the cell surface molecules expression that could explain some immunological disorders characteristic of CVID. Moreover, some immunophenotypical aspects can correlate with clinical features of the disease. We used this procedure to analyze a cohort of 23 patients affected by CVID, in order to identify the novel alterations of B cells and to find the possible correlations with clinical features. Circulating B cells were studied by flow cytometry incubating whole blood with specific antibodies for B cell surface molecules including CD27, IgM, IgD, CD21, and CD23. We compared the population of ¡°switched memory¡± IgD£¿ CD27+ B lymphocytes with the population of ¡°switched memory¡± IgM£¿ IgD£¿ CD23£¿ CD27+ B cells. These last B cells were reduced in patients compared to healthy controls; moreover, IgM£¿ IgD£¿ CD23£¿ CD27+ B cells were lower than IgD£¿ CD27+ B cells in patients with CVID. The reduction of this subset of B lymphocytes correlates more tightly than IgD£¿ CD27+ B cells with lymphadenopathy and airways infections. In conclusion, our findings may help in better identifying patients with CVID. 1. Introduction Common variable immunodeficiency (CVID) is the most common primary immunodeficiency in clinical practice. CVID represents a large heterogeneous group of syndromes characterized by low serum levels of IgG, IgA, and/or IgM, with decreased antibody production and impaired antibody response to both polysaccharide and protein antigens [1¨C3]. As a result of low antibody levels, most CVID patients have recurrent airway infections by capsulated bacteria. Autoimmune diseases, lymphoproliferative, granulomatous or neoplastic disorders, and intestinal dysfunctions may also affect CVID patients. The majority of the genetic mechanisms leading to CVID are still unclear. Defects in the genes that encode for inducible costimulator (ICOS), transmembrane activator and CAML interactor (TACI), CD19, B-cell activating factor receptor (BAFFR), CD81, CD20, and CD21 have been reported [1, 4¨C6]. The identification and analysis of these gene defects have led to novel hypothesis on the pathogenesis of CVID. However, gene defects have been identified in less than 10% of patients, and therefore they account only for
%U http://www.hindawi.com/journals/isrn.immunology/2013/512527/