title: [Diagnostic clinical trial with allergen extract from Blomia tropicalis in allergic adults and healthy volunteers].
abstract: BACKGROUND
  There are no antecedents in Cuba of studies developed to prove the efficacy of an allergy test to Blomia tropicalis despite of being one of the main mites which cause this ailment which affects more than 2,200,000 people.
  
  
  OBJECTIVE
  Evaluate the allergenic extract Blomia tropicalis elaborated at the Centro Nacional de Biopreparados (BioCen), in the prick skin test, as a diagnose of allergy to this allergen which exists in all the tropical and subtropical countries.
  
  
  METHODS
  We selected 50 patients with a positive clinic history of allergy to house dust and 50 healthy persons. Al the persons selected were skin prick tested with dilution's of the extracts (20,000 UB/mL) and positive and negative control. We measured the average diameter of the wheal and the perpendicular diameter, then we calculated the average. We also calculated size of the wheal in the duplicated, which constituted the size of the reaction. We estimated the validity of the test calculating the sensitivity and specificity. We used the EPITABLE program to do this.
  
  
  RESULTS
  The skin prick tested positive in 78% of the patients and 6% in the healthy persons, for a sensitivity of 78% the interval of confidence (IC) 63.7-88.0 and a specificity of 94%, IC 82.5-98.4 the predictive negative value 81%, IC 68.2-89.7.
  
  
  CONCLUSIONS
  The allergenic extract of Blomia tropicalis elaborated in BioCen is very sharp to test the allergy to this mite.
authors.affiliation: Departamento de Alergenos, Centro Nacional de Biopreparados La Habana. olimpio@finlay.cmw.sld.cu
authors.forename: O
authors.initials: O
authors.lastname: Rodríguez Santos
authors.forename: M
authors.initials: M
authors.lastname: Benítez Trujillo
authors.forename: A
authors.initials: A
authors.lastname: Labrada
authors.forename: V
authors.initials: V
authors.lastname: Jove Morales
mesh_terms: D000053:Acari / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000485:Allergens; D000818:Animals; D004391:Dust / Q000009:adverse effects; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged
chemical_list: D000485:Allergens; D004391:Dust
vernacular_title: Ensayo clínico diagnóstico con extracto alergénico de Blomia tropicalis en adultos alérgicos y voluntarios sanos.