Development and Clinical Evaluation of Immunoluminometric Assays for Lactoferrin and Elastase-cti-Proteinase Inhibitor Complexes in Body Fluids with Special References to Bronchoalveolar Lavage and Neonatal Sepsis

Dedicated to Professor H. G. Hansen on the occasion of his 65th birthday Summary: Immunpluimnometric assays for lactoferrin and elastase-cti-proteinase inhibitor complexes were developed using solid-phase methodology, which has already been published from this laboratory. The aim of the study was to develop ä rapid method to see whether elevated granulocyte activity was present in the lung, as for example in neonatal sepsis. The lactoferrin assay gave reliable results within 30 minutes, the elastase^ttt-proteinase inhibitor complexes, within 5 hours. The correlation between both analytes was good, so that the lactoferrin assay could replace the elastase-ar proteinase inhibitor assay in emergency cases. The lactoferrin assay was used for rapid answer, the elastase--pröteinase inhibitor complex assay for "fine " monitoring of the progress of the disease. Both assays could be used to measure concentrations in plasma or bronchoalveolar lavage using a 10 sample. Plasma for the elastase-aj-proteinase inhibitor complex determination had to be diluted 1:50 before being assayed. Only EDTA plasma was used in the assay, as either heparin plasma or serum resulted in granulocyte destruction, thus giving rise to elevated, and non-reproducible results. The results from bronchoalveolar lavage show an excellent correlation between elastase-dj-proteinase inhibitor complexes and lactoferrin. No interference was seen from lipaemic or icteric plasma samples. Results from haemolytic samples i. e. wher