Historical exposures in hypersensitivity pneumonitis
A case-referent study of the exposure history of adults with hypersensitivity pneumonitis
Royal Brompton and Harefield NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 0 days
Hypersensitivity pneumonitis (HP) is a form of interstitial lung disease (ILD). It is an allergic disease of the lung usually caused by inhaled, particulate proteins, often due to an occupational or environmental exposure. Chronic or sub-acute HP causes cough, weight loss and breathlessness and can lead to irreversible lung scarring or fibrosis and premature death from respiratory failure. Current treatment options are limited. Evidence suggests that the prognosis of HP is improved with avoidance of further exposure to the causative allergen. However, not infrequently, an antigen source is never determined.
This is an observational case-referent pilot study designed to determine whether a detailed exposure questionnaire can determine the cause of sub-acute and chronic hypersensitivity pneumonitis (HP).
This single site study will be carried out at Royal Brompton Hospital. Almost all patients referred here to the ILD service (of whom a proportion will have HP) undergo bronchoscopy as part of their diagnostic work-up. We will invite all adult patients who are having a bronchoscopy, to complete, on the day of their procedure, a detailed questionnaire about their historical exposures to potential causal agents of relevance to their ILD. We will also collect a serum (blood) sample for analysis of potentially relevant antibodies.
During the bronchoscopy, a bronchoalveolar lavage (BAL) will be taken for differential cell count as part of the standard investigations. Patients will be categorised into cases of HP with a BAL lymphocyte count >20% (‘chronic or subacute HP’) or referents with a BAL lymphocyte count <20% (‘other ILD').
The exposure questionnaire responses will be analysed and potentially relevant exposures compared between cases and referents. If important causal antigens are identified from the questionnaire, then specific IgG antibodies against these antigens in patient’s serum will be measured.
The study is funded by the Colt Foundation.
London - Dulwich Research Ethics Committee
Date of REC Opinion
11 Jul 2018
Further Information Favourable Opinion