ACUTE LUNG INFLAMMATION - NEUTROPHIL ELASTASE VERSUS NEUTROPHILS IN THE BRONCHOALVEOLAR LAVAGE - NEUTROPHIL ELASTASE REFLECTS BETTER INFLAMMATORY INTENSITY

Objective: To test the hypothesis whether PMN-Elastase in bronchoalveo lar lavage fluid (BALF) could reflect neutrophil activity in the lower respiratory tract. Design: Prospectively, morphologic findings of acu te and chronic inflammation in the transbronchial lung biopsy specimen s were compared with the numbers of neutrophils in the BALF and the co ncentration of PMNElastase in the same. Setting: Ambulatory outpatient service of bronchology and respiratory physiopathology and intensive care unit of a communal hospital. Patients. 50 ambulatory outpatients and 10 critically ill patients of the ICU, presenting infiltrative lun g diseases. Interventions: Transbronchial lung biopsies and bronchoalv eolar lavage were performed through a fiberoptic bronchoscope. Venous blood samples were obtained after bronchoscopy. Measurements and resul ts. Biopsy specimens and cell count in the BALF were examined by light microscopy. PMN-Elastase and albumin were measured in the BALF-supern atant and in the plasma. C-reactive protein (CRP) and al proteinase in hibitor (a1-PI) were measured in the plasma. Intrapulmonary originatin g PMN-Elastase was calculated with reference to albumin. The results c oncerning acute inflammation obtained by transbronchial lung biopsy (T BLB) (n = 16) correlated better with the levels of PMN-Elastase in the BALF (n = 21) than with the neutrophil count (n = 28) (p < 0.5 versus p < 0.025 for chi2). The sensitivities and specificities of the above methods were respectively 76.9%, 100%, 100% and 100%, 95.2%, 63.1%. T he intrapulmonary originating PMN-Elastase was about 99.7% of the meas ured BALF-Elastase. Conclusion: The PMN-Elastase concentration in the BALF is a more accurate indicator of the inflammatory intensity in the alveolar structures than in the number of neutrophils. It may therefo re be useful to the clinician in his attempt to detect acute inflammat ion in the lower respiratory tract.