Abbreviation list: TNF-α=tumour necrosis factor α, BAL=bronchoalveolar lavage, BALF= bronchoalveolar lavage fluid, HLA=human leucocyte antigen, IFN-γ=interferon γ, DLCO=diffusion capacity of the lung for carbon monoxide, FVC=Forced Vital Capacity, FEV1= Forced Expiratory Volume in one second, FoxP3=forkhead box protein 3 transcription factor