Determination of human neutrophil elastase in bronchoalveolar lavage fluid: homogeneous immunoactivation versus heterogeneous enzyme immunoassay.

Elastase mass concentrations of bronchoalveolar lavage fluid were determined by a homogeneous immunoactivation and a heterogeneous enzyme immunoassay. There was an excellent correlation between both assay systems (y = 1.0376 . x + 1.311; r = 0.9901; n = 43) indicating the suitability of the immunoactivation method for the determination of elastase concentrations in bronchoalveolar lavage fluid as a matrix. Furthermore, dilution of bronchoalveolar lavage fluid samples did not influence the elastase recovery of either assay system.