Plasma lactoferrin reflects neutrophil activation in psoriasis.

We used a biotinylated antibody ELISA technique to measure plasma levels of lactoferrin (LF) and the LF content of peripheral blood PMN in 20 patients with psoriasis, 21 with eczema or other inflammatory skin conditions, 19 patients with malignant skin tumours and 20 healthy control individuals. In psoriasis, plasma LF levels were significantly increased compared with levels in the other skin conditions and in the healthy controls (P less than 0.01). Furthermore, in psoriasis the LF content of circulating PMN was decreased. These findings provide further evidence that in psoriasis systemic activation ('priming') of circulating PMN may take place.