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Thirty patients with stable chronic airflow obstruction receiving regular bronchodilator treatment were studied to determine whether the level of bronchial responsiveness, transfer factor for carbon monoxide (TLCO), or the mechanical properties of the lung predicted a bronchodilator response to oral corticosteroid treatment. Before treatment mean (SD) FEV1 was 48% (16%) of the predicted value (% pred); the geometric mean concentration of methacholine required to produce a 20% fall in FEV1 (PC20) was 0.44 (range 0.07-3.32) mg/ml; and TLCO was 59% (21%) predicted. The exponential constant (k) defining the shape of the static volume-pressure curve was 146% (66%) predicted and pulmonary conductance relative to predicted lung volume at a transpulmonary pressure of 5 cm H2O (sGL5) was 72% (37%) predicted. After prednisolone treatment (0.6 mg kg-1 day-1 for two weeks) FEV1 increased by 8% (19%) (p less than 0.05) and daily mean peak flow (PEF) by 3% (10%) (p less than 0.01) over pretreatment values. Three patients had an increase in FEV1 of more than 30%, two of whom had sputum eosinophilia (p less than 0.05). The three were among the 13 patients with a reduced sGL5. The increase in FEV1 did not correlate with initial PC20 (r = 0.16), k (r = -0.12), or TLCO (r = -0.14). Thus measurements of bronchial responsiveness, lung distensibility, and TLCO did not predict corticosteroid response in patients with stable chronic airflow obstruction. Patients with sputum eosinophilia or reduced pulmonary conductance may be more likely to respond. [ABSTRACT FROM AUTHOR]

The pathological features in the lung in asbestosis and cryptogenic fibrosing alveolitis are similar. Patients with asbestosis, however, appear to have less severe impairment of transfer factor (TLCO) than those with fibrosing alveolitis for a given level of radiographic abnormality when assessed on the basis of the International Labour Organisation (ILO) profusion score. The impairment of lung function in the two disorders has been compared in more detail in 29 patients with asbestosis and 25 with fibrosing alveolitis, arterial oxygen desaturation during exercise being used to define the severity of the disorders. Arterial oxygen saturation (ear oximeter) and oxygen uptake were measured during incremental exercise on a cycle ergometer. TLCO (single breath technique) and total lung capacity (TLC, plethysmograph) were measured. Chest radiographs were graded for profusion according to the ILO international classification. Patients with asbestosis had significantly higher mean values for TLCO and TLC and lower mean profusion scores than those with fibrosing alveolitis. When stratified for the degree of arterial oxygen desaturation, however, no significant differences were found in TLCO, TLC, or profusion score between the two disorders. To the extent that arterial oxygen desaturation with exercise reflects the morphological severity of the disease, these results suggest that, for a given degree of interstitial lung disease, asbestosis and cryptogenic fibrosing alveolitis are functionally and radiologically similar. [ABSTRACT FROM PUBLISHER]

Anomalies in the ratio of transfer factor to effective alveolar volume as an indicator of pulmonary gas exchange in cases of asbestosis may be related to diffuse pleural thickening. To examine the effect of pleural disease on gas transfer the plain chest radiographs of patients with asbestosis were assessed by two observers for profusion of parenchymal opacities and extent of pleural disease and the results were related to lung function. In 30 cases of category 1 profusion of parenchymal abnormality (according to the ILO international classification of radiographs for pneumoconiosis) transfer factor was independent of the degree of pleural thickening. The ratio of transfer factor to effective alveolar volume correlated directly with the degree of pleural thickening as alveolar volume fell with increasing severity of pleural disease. The results indicate that correcting transfer factor for alveolar volume does not provide an accurate reflection of severity of diffuse parenchymal fibrosis in patients with asbestosis and even minor pleural disease. [ABSTRACT FROM AUTHOR]

We have reviewed 22 patients with benign asbestos pleural effusion seen over a 17-year period. The mean duration of exposure to asbestos was 5.5 years and the mean interval between exposure and presentation was 16.3 years. In five the effusion was asymptomatic. Fever was uncommon but in 15 of 21 patients the ESR was elevated. Leucocytosis was noted in seven of 20 patients. Autoantibodies were rarely detected. The pleural fluid was usually blood-stained and the volume aspirated was rarely larger than 500 ml. Pleural biopsies revealed established pleural fibrosis and/or inflammatory infiltration with fibrinous exudate and mesothelial and fibroblastic proliferation. A positive mantoux test was noted in eight of 12 patients but there was no other evidence of tuberculosis. The mean duration to spontaneous resolution of the effusion was 4.3 months. During a follow-up period of 28.1 years from initial exposure to asbestos (mean 22.8 years) and up to 17.2 years from initial presentation with a pleural effusion (mean 6.3 years) seven patients had a single recurrence and only one patient had multiple pleural effusions. Only three patients experienced persistent pleural pain. It was not possible to predict the likelihood of recurrence of an effusion or the persistence of pleural pain from the data at presentation. No patient subsequently developed mesothelioma or other neoplasm. [ABSTRACT FROM AUTHOR]

This retrospective study compares the pulmonary function of 24 coal workers with Caplan's syndrome with that of 36 subjects with non-rheumatoid progressive massive fibrosis (PMF). Allowing for differences in radiographical category, age, years worked underground, and smoking, obstruction to air flow as reflected in the one-second forced expiratory volume, the vital capacity, and the ratio of residual volume to total lung capacity, was significantly less in subjects with Caplan's syndrome. No significant differences in transfer factor were found. These findings may be explained by the different pathological features of the two entities. Selection bias does not appear to be responsible for the differences observed between the groups, but studies designed to eliminate this would be desirable. [ABSTRACT FROM AUTHOR]

Sixty-six subjects, mainly derived from various occupational groups and one-third of whom admitted to dyspnoea on exertion, have been grouped according to the appearance of their peripheral airways at bronchography with oily propyliodone. Eleven subjects showed marked peripheral pooling of radiographic contrast material, 22 showed mild or moderate pooling, and in 33 peripheral pools were absent. Pooling was not seen in non-smoking subjects. In the group of subjects without pooling, pulmonary function in non-smokers and subjects with a history of smoking was similar. Subjects with marked pooling had a significantly lower pulmonary diffusing capacity (transfer factor) and evidence of loss of pulmonary elastic recoil when compared with subjects with absent peripheral pooling. These results indicate that bronchographic peripheral pooling is associated with the physiological changes of panacinar pulmonary emphysema and suggest that a causal relationship may exist between the organic bronchiolar lesion of pooling and the peripheral parenchymal lesion of panacinar emphysema. [ABSTRACT FROM PUBLISHER]