[Changes in lung function after a bronchial provocation test with cockroach antigens].

Abstract

BACKGROUND:

Cockroach allergens sensitized patients at a very young age and can predispose to severe asthma on atopic children.

OBJECTIVE:

To evaluate the FEV, changes induced after bronchoprovocation with Blatella germanica (Bg) or placebo on allergic respiratory children.

MATERIAL AND METHODS:

A prospective transversal study was performed in 25 children from 8 to 16 yr with allergic rhinitis and/or asthma diagnosis with sensibility only to Bg (Bayer Corp allergens) by Prick skin test, with a 1:20 weight/volume dilution. After previous training on spirometry, they assisted for a double blind bronchial challenge with 10, 25, 50, 75, 100, 150, 200, 300, 400, 500 until 750 proteic nitrogen units of Bg or 0.9% NaCl solution in a nebulized open circuit, with a 5 litter flow for 3 min. A week after, they returned for the crossover double blind bronchial challenge. At the beginning of the study a basal spirometry was performed and subsequent spirometrics at 1.5 and 3 min after each challenge with a 10 min rest between the challenges. The test was interrupted if cough, dyspnea, wheezing and/or a 15% or more FEV1 fall appeared.

RESULTS:

Twelve patients showed a FEV1 fall with the antigen challenge, all with specific lgE for Bg. All they had positive skin test to Bg, 9 had asthma and rhinitis and 3 only asthma. When placebo was used 6 patients showed a FEV1 fall. When comparing the average basal and final FEV1 values after the challenges, the fall was statistical significant in both groups with a p = 0.0015 when Bg was used, and p = 0.046 with placebo.

CONCLUSION:

These results show that two times fold number of patients challenged with Bg had a FEV1 fall than placebo, and the t Student test showed that antigen challenge was more significant than placebo. We demonstrated that respiratory allergic patients sensitised with Bg after a bronchial challenge with these allergens show a FEV1 fall. This suggests that cockroach allergen sensitisation can be on account of children's asthma.

• Authors: Miguel A Rosas Vargas, Cesar A del Valle López, Blanca Estela del Río Navarro, Juan José Sienra Monge
• Journal: Revista alergia Mexico (Tecamachalco, Puebla, Mexico : 1993) (Rev Alerg Mex) 2003 Jan-Feb Vol. 50 Issue 1 Pg. 13-6 ISSN: 0002-5151 [Print] Mexico
• Vernacular Title: Cambios en la función pulmonar después de una prueba de reto bronquial con antígenos de cucaracha.
• PMID: 12822543 (Publication Type: Clinical Trial, Controlled Clinical Trial, English Abstract, Journal Article)

Chemical References

• Allergens
• Immunoglobulin E

Topics

• Adolescent
• Allergens
• Animals
• Asthma (etiology, immunology, physiopathology)
• Bronchial Provocation Tests
• Child
• Cockroaches (immunology)
• Cross-Sectional Studies
• Double-Blind Method
• Female
• Forced Expiratory Volume
• Humans
• Immunoglobulin E (blood)
• Male
• Prospective Studies
• Rhinitis, Allergic, Perennial (etiology, immunology, physiopathology)
• Skin Tests
• Spirometry