[Functional diagnosis of pulmonary sarcoidosis]

Restrictive disturbances of ventilation of various degree and disorders in diffusing capacity of the lung have been reported as the most frequent disorders in pulmonary sarcoidosis. Recently, however, several authors have found the obstructive disorders of ventilation being present as well, especially in the second stage of disease, and pointed out a possibility of the airways being affected very early at the onset of disease. Present study shows the results of functional tests carried out in 70 patients with histologically verified pulmonary sarcoidosis at all three stages of the disease (classification by Würm). All of them were nonsmokers, aged 20 to 55 years, and had no symptoms of chronic bronchitis, asthma or emphysema, either in case history or clinical findings. They included spirometry, flow-volume loop, body-plethysmography, blood gas analyses at rest and after exercise and pulmonary diffusing capacity for carbon monoxide obtained by single-breath method. Results from the study show the obstructive disorders of ventilation to be dominant in the early stage, while restrictive disturbances dominate in the third stage in pulmonary sarcoidosis. Diffusing capacity of the lung should be measured in the early stage of the disease as well as in those more advanced because of a possibility that interstitial space is being affected, although there is no visible damage on a radiograph. Measurement of pulmonary diffusing capacity together with radiological findings provide a highly valuable data which is of great importance in monitoring the dynamics of this disease.