Common variable immunodeficiency. Old questions are getting clearer.
Common variable immunodeficiency (CVID) is a heterogeneous entity characterized by an impaired ability to produce antibodies. The failure is localized in partially mature B lymphocytes, though T lymphocyte abnormalities are occasionally present. This deficiency affects antibody synthesis and class switch from IgD and IgM, to IgG and IgA. CVID is related to selective IgA deficiency, and both abnormalities may coincide in one same family, and evolve from one to another in the same patient. The symptoms generally manifest in adults, but can occur at any age, even in infancy. Recurrent bacterial infections or pneumonias are frequent, and may be complicated by gastrointestinal problems, granulomas, autoimmune disorders or malignancies. A defect in memory B cells seems to condition the clinical severity. Recently, several mutations in genes encoding for molecules (CD19, TACI, ICOS) involved in B cell survival and isotype switch have been identified in patients with CVID. Nevertheless, genetic abnormalities have been found in less than 25 % of cases with CVID; the underlying mechanism thus remains unknown in the majority of CVID patients, and research in this field must continue.
Blanco-Quirós
A
A
Department of Pediatrics and Instituto de Biología y Genética Molecular (IBGM), University of Valladolid, Ramón y Cajal 5, 47005 Valladolid, Spain. ablanco@ped.uva.es
Solís-Sánchez
P
P
Garrote-Adrados
J A
JA
Arranz-Sanz
E
E
D000328:Adult; D000368:Aged; D000818:Animals; D000917:Antibody Formation; D053264:B-Cell Activating Factor / Q000172:deficiency / Q000276:immunology / Q000502:physiology; D001402:B-Lymphocytes / Q000473:pathology; D023201:CD40 Ligand / Q000032:analysis; D002454:Cell Differentiation; D002648:Child; D002908:Chronic Disease; D002927:Cimetidine / Q000627:therapeutic use; D017074:Common Variable Immunodeficiency / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D006099:Granuloma / Q000209:etiology; D006801:Humans; D017578:Immunoglobulin Class Switching; D007074:Immunoglobulin G / Q000627:therapeutic use; D007136:Immunoglobulins / Q000096:biosynthesis; D015994:Incidence; D007239:Infections / Q000150:complications; D008171:Lung Diseases / Q000209:etiology; D051379:Mice; D018345:Mice, Knockout; D008875:Middle Aged; D053303:Transmembrane Activator and CAML Interactor Protein / Q000172:deficiency / Q000276:immunology; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000172:deficiency / Q000276:immunology / Q000502:physiology
D053264:B-Cell Activating Factor; D007074:Immunoglobulin G; D007136:Immunoglobulins; C108467:TNFRSF13B protein, human; C505719:TNFSF13B protein, human; C491959:Tnfsf13 protein, mouse; C505720:Tnfsf13b protein, mouse; D053303:Transmembrane Activator and CAML Interactor Protein; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13; D023201:CD40 Ligand; D002927:Cimetidine