PT  - JOURNAL ARTICLE
AU  - Chung Hu
AU  - Maria-Jesus Cruz
AU  - Iñigo Ojanguren
AU  - Ferran Morell
AU  - Xavier Muñoz
TI  - Specific challenge tests: The relationship between response, clinical variables and lung function
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - 409
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/409.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/409.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Introduction: The specific inhalation challenge (SIC) is considered the gold standard for the diagnosis of occupational asthma (OA). However, it is not well standardized, and the intensity of exposure is regulated empirically. The aim of this study was to identify clinical variables and/or pulmonary function variables able to predict the magnitude of the response to SIC.Material and methods: All patients who underwent SIC between 2005 and 2013 were studied. Anthropometric characteristics, atopic status, type of causal agent, latency times, pulmonary function tests and SIC results were analysed.Results: 203 patients (51% men, mean age 42.6 ± 11.3 years) were assessed, of whom 88 (43%) had positive SIC. Among patients with positive SIC those with a lower PC20 at baseline presented a greater decline in FEV1 during testing (r = -0376, p = 0.002). In the overall population, the mean (SD) % falls in FEV1 were 23.3 (13.60) and 16.30 (10.13) for patients exposed to high-molecular weight and low molecular weight agents respectively; the differences were significant (p = 0.002). No relationship was observed between the other variables analysed and the fall in FEV1 during SIC.Conclusions: The size of the response to SIC is influenced by a positive methacholine baseline test and by the causal agent. These data should be taken into account in the stages prior to the performance of SIC.