Occult exposure to asbestos in steel workers revealed by bronchoalveolar lavage.

To investigate the asbestos burden in a steelplant environment, we counted asbestos bodies (ABs) in the bronchoalveolar lavage fluid (BALF) of 65 steel workers who had retired during the previous 5 y. They had worked for at least 15 y in the same area of the plant (coke oven or blast furnace) as maintenance or production workers. On the basis of occupational anamnesis, 28 had occasional past professional exposure to asbestos; the remaining 37 workers denied any contact with asbestos. A total of 54 white-collar workers who had no occupational exposure to asbestos were included in the study as controls. An increased prevalence and concentration of ABs was found in the BALF of steel workers. Electron microscopy and EDAX analysis of AB from steel workers revealed that the core fibers were mainly amphiboles. More ABs were found in the BALF of maintenance workers than in production workers. However, the BALF from steel workers who denied any contact with asbestos revealed an increased AB burden v. controls. This demonstrates that steel workers may be subject to an occult exposure to amphiboles in the steelplant environment.

Effect of histamine on chemotaxis and phagocytosis of human alveolar macrophages and blood monocytes.

We studied in vitro the effect of histamine on the chemotactic and phagocytic abilities of human blood monocytes and alveolar macrophages. The chemotactic response to activated autologous serum, leukotriene B4 or N-formyl-methionine-L-phenylalanine was similar for macrophages and monocytes. Incubation of monocytes with histamine in picomolar concentrations caused a significant chemotactic inhibition (about 25%). This effect was antagonized by cimetidine but not by promethazine. Histamine did not have an effect on alveolar macrophages chemotaxis or phagocytosis. Thus, histamine, in minute concentrations, exerts, in vitro, a partial inhibitory effect on monocyte chemotaxis through activation of H2-type receptors.

[Alveolar proteinosis: restoration of the function of the alveolar macrophages after therapeutic lavage]. / Protéinose alvéolaire: restauration fonctionnelle des macrophages alvéolaires après lavage thérapeutique.

The aim of this study was to specify the effect of therapeutic pulmonary lavage on the function of alveolar macrophages in a patient suffering from alveolar proteinosis; we have studied phagocytosis and chemotaxis in cells before and at different times after the lavage. Our results indicate a restoration of the functional properties of the alveolar macrophages in parallel with an improvement in pulmonary function and blood gases under the effects of treatment. These data are in favour with an inhibitory effect of the lipoprotein material on the function of alveolar macrophages and suggest that the deposit of this material is a determining factor in the alteration in the defense mechanisms of the lung.

[Significance of lactate dehydrogenases in pleural effusions]. / Signification des lacticodéshydrogénases des épanchements pleuraux.

In order to determine the exact significance and origin of lactate dehydrogenases (LDH) present in pleural effusions, LDH and their enzymes were assayed in the serum and pleural fluid of 60 patients with wet pleurisy and in the main blood cells (haematocytes, polymorphonuclears mononuclears) found in pleural fluids. Our results showed that: a pleural fluid/serum LDH ratio above 0.7 indicates that the fluid is an exudate; however, in about 10% of inflammatory pleural effusions due to infection or cancer this ratio is comprised between 0.5 and 0.7; the enzyme profile of transudates only differs from that of normal serum by a slight increase in isoLDH 4 and 5; in exudates this profile is the reverse of the normal serum profile, with a decrease in isoLDH 1 and 2 and an increase in isoLDH 4 and 5; the enzyme profile provides little information on the origin of exudates, although a more than 30% rise in isoLDH 2 is in favour of a malignancy (mesothelioma excluded); polymorphonuclears contain more isoLDH 4 and 5 than mononuclears; activation of mononucleate cells is attended by a significant increase in intracellular isoLDH 4 and 5; the presence of red blood cells and/or haemolysis in an exudate cannot account for its high isoLDH 4 and isoLDH 5 content; the high content seems to be due, at least partly, to release of these enzymes by the polymorphonuclears and/or mononucleate cells involved in pleural inflammation.

Lack of correlation between serum angiotensin-converting enzyme activity and bronchoalveolar lymphocytosis in lung sarcoidosis.

Serum angiotensin-converting enzyme activity (SACE) and the number of lymphocytes in bronchoalveolar lavage fluid (BALF) are elevated in many patients with sarcoidosis, and have been proposed as monitors of disease activity. To study the relationship between these two parameters, we have compared SACE values to the percentage of BALF lymphocytes in 23 patients with pulmonary sarcoidosis. Twenty patients had recently diagnosed Stage I or II sarcoidosis and 3 were in Stage III. SACE and BALF lymphocytosis were respectively elevated in 80 and 85% of patients with Stage I and II sarcoidosis, and concordant (i.e. both elevated or both normal) in 75% of these patients. Both SACE and the percentage of BALF lymphocytes were normal in the 3 Stage III patients. No significant correlation was observed between SACE values and the percentage of BALF lymphocytes in our group of 23 patients. Discordance is liable to occur in Stage I patients where increased BALF lymphocytosis and normal SACE may be found, and in smoking patients where elevated SACE may be associated with a normal proportion of BALF lymphocytes.