PLASMA-PROTEIN LEAKAGE AND LOCAL SECRETION OF PROTEINS ASSESSED IN SPUTUM IN ASTHMA AND COPD - THE EFFECT OF INHALED CORTICOSTEROIDS

Asthma and chronic obstructive pulmonary disease (COPD) are characteri zed by chronic airway inflammation with cell infiltration, increased p lasma exudation and abnormal local secretion of proteins. We have anal ysed whether sputum differs in this respect between asthma (n = 9) and COPD (n = 9), and whether inflammatory markers in sputum are affected by treatment. In non-smoking asthma patients there was more plasma pr otein leakage, based on the relative coefficient of excretion Q alpha 2macroglobulin/QIgG (P = 0.03). There was less local secretion of sIgA and lactoferrin than in COPD (P < 0.05). Tryptase was slightly higher in sputum from asthma than from COPD (P < 0.05), whereas eosinophil c ationic protein and myeloperoxidase were similar, After treatment with glucocorticosteroids, there was a reduction in the Q alpha 2macroglob ulin/Qalbumin (P < 0.015), but no effect was seen on the levels of pro ducts from local cells. We conclude that sputum analysis is useful to study the local inflammatory process in asthma and COPD.