title: [Common variable immunodeficiency: Clinical and immunological characterization of patients and homogeneous subgroup definition by means of B lymphocyte subpopulation typing].
abstract: BACKGROUND
  Common variable immunodeficiency is a heterogeneous syndrome characterized by recurrent infections, hypogammaglobulinemia and defective production of specific antibodies. Abnormalities in peripheral blood lymphocyte subpopulations, in particular of B lymphocytes, allow the classification of patients into homogeneous groups.
  
  
  OBJECTIVE
  To perform a clinical and immunological characterization and to evaluate lymphocyte subpopulations of twelve Colombian patients with common variable immunodeficiency in order to define homogeneous groups.
  
  
  METHODS
  We reviewed medical records and evaluated serum immunoglobulins (Ig), lymphoproliferation, delayed hypersensitivity and used flow cytometry to quantify peripheral blood total lymphocyte and B cell populations.
  
  
  RESULTS
  All patients had recurrent respiratory and/or gastrointestinal infections, while some also had infections affecting other systems. All patients had abnormally low serum IgG levels, while IgA and IgM levels were reduced in nine and ten patients, respectively. Lymphoproliferation to mitogen was lower in patients than in healthy controls but lymphoproliferation to specific antigen was normal in all. Flow cytometry revealed high numbers of T cells in three patients, while seven had a low CD4+/CD8+ ratio and four had reduced NK cells . Eleven patients had normal B cell counts, and eight of them also showed decreased memory B lymphocytes, and four had increased transitional or CD21 low B lymphocytes.
  
  
  CONCLUSIONS
  Lymphocyte typing allowed assigning all but one patient to homogeneous groups according to international classification schemes, indicating the necessity of including more criteria until an ideal classification is achieved. This study will lead to a better medical monitoring of common variable immunodeficiency patients in groups at high risk of developing clinical complications.
authors.affiliation: Grupo de Inmunodeficiencias Primarias, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Alejandra Catalina
authors.initials: AC
authors.lastname: Vélez
authors.affiliation: Grupo de Inmunología Celular e Inmunogenética, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Diana María
authors.initials: DM
authors.lastname: Castaño
authors.affiliation: Grupo de Epidemiología, Facultad Nacional de Salud Pública, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Rubén Darío
authors.initials: RD
authors.lastname: Gómez
authors.affiliation: Grupo de Inmunodeficiencias Primarias, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Julio César
authors.initials: JC
authors.lastname: Orrego
authors.affiliation: Grupo de Inmunodeficiencias Primarias, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: Marcela
authors.initials: M
authors.lastname: Moncada
authors.affiliation: Grupo de Inmunodeficiencias Primarias, Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Franco
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016175:B-Lymphocyte Subsets; D002648:Child; D002675:Child, Preschool; D017074:Common Variable Immunodeficiency / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D055815:Young Adult