Aspects of preanalytical variation of lactoferrin and elastase/α1-protease inhibitor complexes

A number of interesting applications of plasma elastase/α1-protease inhibitor complexes (ELA-PI) and lactoferrin (LAC) have recently been suggested. However, the clinical utility of these components often seems to be low. This might be improved by minimizing the preanalytical variation, if possible. Therefore, we have evaluated the influence of various aspects of sampling and handling conditions on the results obtained when measuring ELA-PI and LAC. Blood samples from both healthy persons as well as patients, who had undergone laparotomy the day before, were investigated. We confirmed the previous observations of higher concentrations of ELA-PI and LAC in serum compared to plasma. This was more pronounced in patients than in healthy adults. In EDTA-blood the most important change was seen in samples from patients when stored at room temperature. In this situation increases of LAC concentrations of 50% and 100% following 2 and 5h, respectively were found. This in vitro release of LAC was abolished when sam...