[Diagnostic aspects of allergic alveolitis]

The clinical picture of extrinsic allergic alveolitis (EAA) or hypersensitivity pneumonitis is etiologically extremely multivarious and in disposed persons it can be caused by inhalation of proteins of various species of animals (in particular by avian proteins), mushrooms, bacteria, insects, thermoactinomycetes, vegetable antigens, possibly also haptens after fixation with protein produced inside the body. The inhaled dusts with a size particles of 4 to 5 micrometers which contain the disease-evoking antigens often have an activity-specific character which is expressed in the traditional names of individual forms of alveolitis (e.g. farmer's lung, mushroom-worker's lung, cheese-washer's lung, malt-worker's lung, bagassosis). However, according to our inquiries in the GDR as well as in other parts of Central and East Europe these diseases are relatively rare. In the GDR the so-called bird-fanciers' or bird-keepers' lung with a frequency of 83.4% has a supreme significance within all forms of alveolitis, followed by the farmer's lung (8.9%) and forms of alveolitis by mushrooms (7.7%). In a period of 10 years altogether 7,669 sera of patients with suspicion of alveolitis were investigated at our institute. According to the results of the immunological as well as of further paraclinical and clinical examinations in 550 cases the diagnosis of allergic alveolitis was made (459 bird-fancier's lungs, 49 farmer's lungs and 42 cases of allergic alveolitis by moulds). In 88.5% of the patients who fell ill with extrinsic allergic alveolitis the disease is accompanied by a positive or very positive antigen-specific antibody formation in the blood.(ABSTRACT TRUNCATED AT 250 WORDS)