ELISA FOR DETERMINATION OF IMMUNOREACTIVE FREE ELASTASE AND ELASTASE IN COMPLEX WITH ALPHA-1-ANTITRYPSIN IN NASAL SECRETIONS WITH SINUSITIS

Sensitive double antibody sandwich ELISA methods was developed in order to quantify immunoreactive neutrophil elastase (NE) levels in nasal secretions with chronic sinusitis (CS). Microwell plate as a solid phase was coated with anti-NE antibody. Two different horseradish peroxidase (HRP) labelled antibodies used as the second antibody were anti-NE-HRP for measuring total (free + complexed) NE level and anti-alpha-1-antitrypsin (AT)-HRP for complexed NE level. Mean value of total NE was 31.0 +/- 20.7-mu-g/ml in nasal secretions from adult patients with CS, and the percentage of complexed NE in total NE was 33.7 +/- 21.4%. This sandwich ELISA is a useful method for measuring both total and complexed NE levels in nasal secretions.