title: Common variable immunodeficiency: association between memory B cells and lung diseases.
abstract: BACKGROUND
  Malabsorption syndrome often develops in patients with common variable immunodeficiency (CVID). Why structural damages appear in some CVID patients and not in others is not fully understood. Memory B cells (MBs) are responsible for the production of specific antibodies, and their defects have previously been related to autoimmune, granulomatous, and lymphoproliferative complications of CVID. The objective of this study was to ascertain whether a relationship exists between MB defects and the clinical outcome of respiratory and intestinal involvement in these patients.
  
  
  METHODS
  Forty-one CVID patients were grouped as follows, according to the quantification of peripheral MBs: the MB2 group (n = 7) included patients with normal MBs; the MB1 group (n = 16) included patients with low switched MBs; and the MB0 group (n = 18) included patients with absent/low MBs. The clinical outcome of respiratory and intestinal involvement of patients was then compared among the three groups.
  
  
  RESULTS
  In the MB0 group, chronic lung disease (ie, bronchiectasis and diminished FVC and/or FEV1) developed in 50% of patients vs 13% in the MB1 group and 0% in the MB2 group (p < 0.05). In the MB0 group, malabsorption syndrome or chronic noninfectious diarrhea developed in 50% of patients vs 19% in the MB1 group and 0% in the MB2 group (p < 0.05). No differences were found among the three groups for age at onset of symptoms, delay in diagnosis/treatment, months of follow-up/treatment, and prediagnostic serum IgG concentration.
  
  
  CONCLUSIONS
  Alterations in MB count appear to be associated with a severe clinical outcome of respiratory and intestinal involvement in CVID. The MB count could be a useful laboratory parameter for orienting the prognosis and management of CVID patients.
authors.affiliation: Immunology Unit, University Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Drahomíra
authors.initials: D
authors.lastname: Detková
authors.forename: Javier
authors.initials: J
authors.lastname: de Gracia
authors.forename: Susana
authors.initials: S
authors.lastname: Lopes-da-Silva
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vendrell
authors.forename: Antonio
authors.initials: A
authors.lastname: Alvarez
authors.forename: Luisa
authors.initials: L
authors.lastname: Guarner
authors.forename: Antonio
authors.initials: A
authors.lastname: Vidaller
authors.forename: Maria-José
authors.initials: MJ
authors.lastname: Rodrigo
authors.forename: Isabel
authors.initials: I
authors.lastname: Caragol
authors.forename: Teresa
authors.initials: T
authors.lastname: Espanol
authors.forename: Manuel
authors.initials: M
authors.lastname: Hernández
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D002908:Chronic Disease; D017074:Common Variable Immunodeficiency / Q000150:complications* / Q000276:immunology* / Q000473:pathology; D003967:Diarrhea / Q000209:etiology / Q000276:immunology / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007156:Immunologic Memory; D008171:Lung Diseases / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D008286:Malabsorption Syndromes / Q000209:etiology / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis