Abstract

Bronchoalveolar lavage was performed in eight patients with biopsy proved sarcoidosis and eight control subjects matched for age and smoking habit, three sequential 60 ml aliquots of sterile saline being used. Each aliquot was aspirated and analysed separately to determine total and differential cell counts. Cellular metabolic activity was stimulated with latex and measured by means of luminol enhanced chemiluminescence to assess neutrophil activity and lucigenin enhanced chemiluminescence to assess macrophage activity. In control subjects mean total cell counts were significantly greater in the second aspirate than in the first, but fell slightly in the third. Similarly, in the patients with sarcoidosis mean total cell counts increased from aspirate 1 to a maximum in aspirate 2, before falling again marginally in aspirate 3. The only significant difference in cell counts between patients with sarcoidosis and controls was an approximately threefold increase in total lymphocyte counts in the former in each of the three aspirates. Luminol chemiluminescence was similar in patients with sarcoidosis to that in controls in the first aspirate, but was significantly greater in the second and third aspirates. Lucigenin chemiluminescence was also significantly greater in the second and third aspirates only. Thus in patients with sarcoidosis lymphocyte numbers are increased in all three aspirates whereas cellular metabolic activity is increased to a greater extent in later aspirates, which may reflect events occurring in the periphery of the lung segment.