Plasmalactoferrin and the plasmalactoferrin/neutrophil ratio. A reassessment of normal values and of the clinical relevance.

In healthy subjects normal plasmalactoferrin (PLf) concentrations were found to be 0.206 +/- 0.06 mg/l in 49 men and 0.148 +/- 0.06 mg/l in 62 women. A highly significant correlation of PLf with the number of circulating neutrophils (PMN) and a PLf/PMN relationship suggesting proportionality was demonstrated. Among 73 patients absolute PLf concentrations were significantly increased in septicemia, cirrhosis of the liver and tumors with liver metastases, decreased in localized infection, tumors without liver involvement, iron deficiency and acute hepatitis B, and normal in acute myocardial infarction. The PLf/PMN ratio, on the other hand, was normal in liver cirrhosis, hepatitis B and in a part of the patients with septicemia and tumor disease with liver involvement. The ratio was increased in a part of the septicemic patients, and decreased in the remaining disease types. Positive PLf/PMN correlations were found in myocardial infarction, septicemia and liver cirrhosis, whereas a very close, negative correlation existed in acute hepatitis B. These findings are discussed on the basis of existing knowledge on lactoferrin physiology, the intravascular fate of PMN and the RES function.