title: Allergen vaccination with a liposome-encapsulated extract of Dermatophagoides pteronyssinus: a randomized, double-blind, placebo-controlled trial in asthmatic patients.
abstract: BACKGROUND
  Liposomes are potent immunologic adjuvants and have been proposed as allergen carriers in allergy vaccination.
  
  
  OBJECTIVE
  We sought to investigate the efficacy and safety of vaccination with Dermatophagoides pteronyssinus encapsulated in liposomes.
  
  
  METHODS
  We conducted a double-blind, placebo-controlled study. Fifty-five asthmatic patients sensitized to mites were randomly assigned vaccination with D pteronyssinus extract encapsulated in liposomes or empty liposomes for a period of 12 months. The principal parameters were symptom and medication-consumption scores. The percentage of healthy days (ie, days without medication and with absent or mild symptoms) was calculated. Immediate and late skin test results, allergen bronchial challenge test results, and allergen-specific serum immunoglobulin levels were evaluated before and after treatment.
  
  
  RESULTS
  All clinical scores were markedly lower in the active group than in the placebo group after vaccination. Nearly half (45.8%) of the patients actively treated reduced their symptom and medication scores by at least 60% versus only 12% of patients receiving placebo treatment (P =.0388). The percentage of healthy days in the active group rose from 10.5% before treatment to 64.5% afterward (P =.0008). Reduction in organ sensitivity was demonstrated by skin prick test responses (P <.01), late-phase response after intradermal testing (P =.009), and bronchial challenge test results (P =.026) in the active group. Serum levels of specific IgG increased throughout the treatment, whereas specific IgE levels showed only an initial transient increase. No change in these parameters was observed in the placebo group. Vaccination was well tolerated, and no subcutaneous nodules appeared.
  
  
  CONCLUSIONS
  Vaccination with D pteronyssinus encapsulated in liposomes is an effective and safe treatment for allergy-induced asthma.
authors.affiliation: Hospital Universitario La Fe, Valencia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Basomba
authors.forename: Ana I
authors.initials: AI
authors.lastname: Tabar
authors.forename: Dolores Hernández F
authors.initials: DH
authors.lastname: de Rojas
authors.forename: Blanca E
authors.initials: BE
authors.lastname: García
authors.forename: Remedios
authors.initials: R
authors.lastname: Alamar
authors.forename: José M
authors.initials: JM
authors.lastname: Olaguíbel
authors.forename: Jaime Moscoso
authors.initials: JM
authors.lastname: del Prado
authors.forename: Santiago
authors.initials: S
authors.lastname: Martín
authors.forename: Pilar
authors.initials: P
authors.lastname: Rico
mesh_terms: D000293:Adolescent; D000328:Adult; D039741:Antigens, Dermatophagoides; D001249:Asthma / Q000628:therapy*; D001985:Bronchial Provocation Tests; D003888:Desensitization, Immunologic; D015930:Diet Records; D004311:Double-Blind Method; D005260:Female; D006023:Glycoproteins / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008081:Liposomes; D008297:Male; D008875:Middle Aged; D012882:Skin Tests
chemical_list: D039741:Antigens, Dermatophagoides; D006023:Glycoproteins; D007074:Immunoglobulin G; D008081:Liposomes; D007073:Immunoglobulin E