Indium-111 labelled granulocyte scanning to detect inflammation in the lungs of patients with chronic sputum expectoration.

Thirty eight patients with chronic sputum expectoration underwent indium-111 labelled granulocyte lung scanning and measurement of whole body loss of indium-111 labelled granulocytes. Twenty four patients had radiologically proved bronchiectasis and 14 had mucus hypersecretion without radiological evidence of bronchiectasis. None was having an acute exacerbation at the time of the scan. The median 24 hour volume of sputum expectorated was 17 (range 2-175) ml. The 24 hour volume of purulent sputum was 5 (0-142) ml; six patients expectorated mucoid sputum only. Twenty one of the 38 patients had a positive granulocyte lung scan. All nine patients expectorating more than 20 ml purulent sputum in 24 hours had positive lung scans and all had lost more than 19% of the indium-111 from the body after five to seven days. Of the six patients with mucoid sputum, only one had a positive scan and these subjects lost only 6-11% of the indium-111 in five to seven days. The percentage loss of indium-111 from the body correlated with 24 hour purulent sputum volume (r = 0.41, n = 38, p less than 0.001) and total elastolytic activity in 24 hour sputum (r = 0.54, n = 14, p less than 0.01). The loss of indium-111 was not related to the extent of bronchiectasis when purulent sputum volume was allowed for. Indium-111 labelled granulocyte scanning provides a sensitive and objective method for detecting inflammation in the lungs and should help to improve understanding of chronic bronchial sepsis and possibly treatment in selected cases.