title: Infection outcomes in patients with common variable immunodeficiency disorders: relationship to immunoglobulin therapy over 22 years.
abstract: BACKGROUND
  Common variable immunodeficiency disorders (CVIDs) are the most common forms of symptomatic primary antibody failure in adults and children. Replacement immunoglobulin is the standard treatment, although there are few consistent data on optimal dosages and target trough IgG levels required for infection prevention.
  
  
  OBJECTIVE
  To provide data to support the hypothesis that each patient requires an individual dose of therapeutic immunoglobulin to prevent breakthrough infections and that efficacious trough IgG levels vary between patients.
  
  
  METHODS
  Data, collected prospectively from a cohort of 90 patients with confirmed CVIDs from 1 center over a follow-up period of 22 years, was validated and analyzed. Immunoglobulin doses had been adjusted in accordance with infections rather than to achieve a particular trough IgG level. Doses to achieve infection-free periods were determined and resultant trough levels analyzed. A smaller group of patients with X-linked agammaglobulinemia was analyzed for comparison.
  
  
  RESULTS
  Patients with a CVID had a range of trough IgG levels that prevented breakthrough bacterial infections (5-17 g/L); viral and fungal infections were rare. Doses of replacement immunoglobulin to prevent breakthrough infections ranged from 0.2 to 1.2 g/kg/mo. Those with proven bronchiectasis or particular clinical phenotypes required higher replacement doses. Patients with X-linked agammaglobulinemia showed a similar range of IgG levels to stay infection-free (8-13 g/L).
  
  
  CONCLUSIONS
  These data offer guidance regarding optimal doses and target trough IgG levels in individual patients with CVIDs with or without bronchiectasis and for particular clinical phenotypes. The goal of replacement therapy should be to improve clinical outcome and not to reach a particular IgG trough level.
authors.affiliation: Department of Clinical Immunology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Mary
authors.initials: M
authors.lastname: Lucas
authors.forename: Martin
authors.initials: M
authors.lastname: Lee
authors.forename: Jenny
authors.initials: J
authors.lastname: Lortan
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lopez-Granados
authors.forename: Siraj
authors.initials: S
authors.lastname: Misbah
authors.forename: Helen
authors.initials: H
authors.lastname: Chapel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000209:etiology / Q000517:prevention & control*; D001987:Bronchiectasis / Q000209:etiology; D017074:Common Variable Immunodeficiency / Q000150:complications / Q000276:immunology / Q000503:physiopathology / Q000628:therapy*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage* / Q000009:adverse effects; D007167:Immunotherapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013163:Splenomegaly / Q000209:etiology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D016756:Immunoglobulins, Intravenous