Portal de Periódicos da CAPES

Histamine challenges discriminate between symptomatic and asymptomatic children

2001; European Respiratory Society; Volume: 17; Issue: 2 Linguagem: Inglês

10.1183/09031936.01.17202460

1399-3003

B. Niggemann, Sabina Illi, C. Madloch, K. Völkel, Susanne Lau, Renate L. Bergmann, Erika von Mutius, Ulrich Wahn,

Respiratory and Cough-Related Research

The aims of this study were to investigate a threshold value for bronchial responsiveness in children aged 7 yrs, which discriminates between symptomatic and asymptomatic children, and to identify determinants of this responsiveness. Titrated bronchial histamine challenges using the reservoir method were performed in 645 children aged 7 yrs, from the birth cohort Multicentre Allergy Study (MAS). When defining a reference population of healthy children within the MAS cohort, the 95th percentile of the provocative concentration causing a 20% fall in forced expired volume in one second PC 20 among these asymptomatic study subjects amounted to 0.60 mg·mL −1 . This resulted in a specificity of 93.0% and a sensitivity of 45.9%, for discriminating between “current wheezers” and “non-current wheezers”. Determinants of airway responsiveness at this age were pulmonary function, sensitization to indoor allergens, total immunoglobulin E and current wheeze. The results indicate that a very low cut-off provocative concentration causing a 20% fall in forced expired volume in one second (<1.0 mg·mL −1 ) defines airway hyperresponsiveness in children aged 7 yrs using the reservoir method. Provocation protocols for histamine challenges in this age group should therefore start with concentrations markedly below 1.0 mg·mL −1 .