The prevalence and predictors of airway hyperresponsiveness in sarcoidosis

• Published in: Respirology (Carlton, Vic.) Vic.), 2012-05, Vol.17 (4), p.653-659
• Main Authors: YOUNG, LISA M., GOOD, NICHOLA, MILNE, DAVID, ZENG, IRENE, KOLBE, JOHN, WILSHER, MARGARET L.
• Format: Article
• Language: English
• Subjects: Adult; Airway Remodeling - physiology; asthma; Asthma - physiopathology; Bronchial Hyperreactivity - epidemiology; Bronchial Hyperreactivity - physiopathology; Bronchial Provocation Tests - methods; bronchoprovocation; Chest; Comorbidity; Computed tomography; Female; Fibrosis; Histamine; Humans; hypertonic saline; Inflammation; Lung; Male; Middle Aged; Multivariate analysis; Prevalence; Respiratory Function Tests; Respiratory tract; Sarcoidosis; Sarcoidosis, Pulmonary - epidemiology; Sarcoidosis, Pulmonary - physiopathology
• ISSN: 1323-7799; 1440-1843
• DOI: 10.1111/j.1440-1843.2012.02137.x

ABSTRACT Background and objective:  Obstructive airflow limitation is the most common physiological impairment in sarcoidosis. This study determined the prevalence of airway hyperresponsiveness (AHR) in sarcoidosis, the correlation between responses to direct (using histamine) and indirect (using hypertonic saline) bronchial challenge, and the clinical, physiological and radiological predictors of AHR. Methods:  Subjects with sarcoidosis and a baseline forced expiratory volume in 1 s (FEV1) >35% predicted underwent hypertonic and histamine challenge, lung function testing and high resolution computed tomography (HRCT) of the chest. AHR was defined as a 15% fall in FEV1 to hypertonic saline and a 20% fall in FEV1 to histamine. Results:  The 52 subjects had well‐preserved lung function (FEV1 = 2.8 ± 0.7 L, 87% predicted). AHR was detected in 5/47 (11%) to hypertonic saline and 19/43 (44%) to histamine challenge. On univariate analysis, response to histamine challenge was predicted by conglomerate fibrosis (P = 0.02) and reticular pattern (P = 0.03) on HRCT. The baseline % predicted forced expiratory volume in 1 s was significantly inversely associated with AHR on univariate (P = 0.004) and multivariate analysis (P = 0.01) when adjusted by HRCT patterns. Conclusions:  The higher prevalence of AHR using histamine challenge than hypertonic saline challenge and the association with baseline % predicted FEV1 suggest that the AHR in sarcoidosis may reflect the consequences of airway remodelling following inflammation. We found a higher prevalence of airway hyperresponsiveness (AHR) in patients with sarcoidosis using direct (histamine) challenge than indirect (hypertonic saline) challenge, and AHR was inversely associated with baseline % predicted FEV1. This suggests that AHR in sarcoidosis reflects the consequences of airway remodelling following inflammation.