title: Autoimmunity and infection in common variable immunodeficiency (CVID).
abstract: Common variable immunodeficiency (CVID) is a heterogeneous group of diseases, characterized by primary hypogammaglobulinemia. B and T cell abnormalities have been described in CVID. Typical clinical features of CVID are recurrent airway infections; lymphoproliferative, autoinflammatory, or neoplastic disorders; and autoimmune diseases among which autoimmune thrombocytopenia (ITP) is the most common. The coexistence of immunodeficiency and autoimmunity appears paradoxical, since one represents a hypoimmune state and the other a hyperimmune state. Considering both innate and adaptive immune response abnormalities in CVID, it is easier to understand the mechanisms that lead to a breakdown of self-tolerance. CD21(low) B cells derive from mature B cells that have undergone chronic immune stimulation; they are increased in CVID patients. The expansion of CD21(low) B cells is also observed in certain autoimmune diseases. We have studied CD21(low) B cells in patients with CVID, CVID, and ITP and with ITP only. We observed a statistically significant increase in the CD21(low) population in the three pathological groups. Moreover, we found statistical differences between the two groups of CVID patients: patients with ITP had a higher percentage of CD21(low) cells. Our data suggest that CD21(low) cells are related to autoimmunity and may represent a link between infection and autoimmunity.
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Patuzzo
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Barbieri
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Tinazzi
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Dino
authors.initials: D
authors.lastname: Veneri
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Argentino
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Moretta
authors.affiliation: Immunology Area, Pediatric Hospital Bambino Gesù, Rome, Italy; University of Genoa, Genoa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Puccetti
authors.affiliation: Department of Medicine, University of Verona, Verona, Italy. Electronic address: claudio.lunardi@univr.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Lunardi
mesh_terms: D000328:Adult; D015551:Autoimmunity / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001424:Bacterial Infections / Q000276:immunology* / Q000382:microbiology; D017074:Common Variable Immunodeficiency / Q000150:complications / Q000276:immunology*; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000150:complications / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
keywords: Autoimmunity; CD21(low) B cells; Chronic inflammatory diseases; Common variable immunodeficiency; Recurrent infections