Signs of alveolar inflammation in non-smoking Swedish wood trimmers

Wood trimmers are periodically exposed to mould and may develop extrinsic allergic alveolitis (EAA). To investigate if there were any signs of EAA in wood trimmers with low exposure, 19 non-smoking wood trimmers underwent bronchoalveolar lavage (BAL), spirometry, and measurement of diffusion capacity (TLCO). The group was subdivided into those with (n = 9) and without serological antibodies against mould. In 14 workers the TLCO was measured both at the beginning and at the end of a week at work. Twenty five healthy non-smokers served as BAL controls and 19 healthy non-smokers as lung function controls. The median exposure of total dust was well below the Swedish threshold value, and the exposure of mould and bacteria was also low. The cell concentrations and the proportions of the various alveolar cells did not differ between the groups. The concentrations of the soluble components albumin, fibronectin, and hyaluronan were, however, significantly increased (p less than 0.001 for all) in the workers. No difference was found in lung function between the workers and the controls, and the TLCO was not impaired during a week at work. The groups of seropositive and seronegative workers did not differ in any of these parameters. The results are interpreted as a low intensity alveolar inflammation. The presence of precipitating antibodies against mould did not predict any greater risk of developing a more intense inflammation. Analysis of soluble non-cellular BAL components seems to reflect a discrete ongoing alveolar inflammation better than cell counts only.