Neopterin plasma levels in burn patients

Burn victims have severely depressed cellular immunity and despite careful hygiene, antibiotics and early surgical therapy the infection rate remains high. The assessment of plasma neopterin levels can be considered as an indirect measurement of macrophage function, because activation of macrophages is accompanied by the release of D-erythro-neopterin. The influence of burn trauma on neopterin levels was investigated to determine whether neopterin estimations might have a prognostic or diagnostic value. Twenty patients with a mean age of 36 +/- 16 years and a TBSA of 45.5 per cent +/- 23 were studied. During the whole hospital treatment daily blood samples were analysed for neopterin levels using radioimmunoassay. Starting from normal levels (9 +/- 1.6 nmol/l), neopterin content increased continuously until day 10 (30-40 nmol/l), then fluctuated around these high levels for several weeks. There were no differences between patients with TBSA less than 35 per cent or greater than 35 per cent, and between survivors and non-survivors. Burn injury caused a constant increase of plasma neopterin indicating an intact reaction by macrophages. It can be used as an additional parameter for the diagnosis of sepsis: high values being a sign of adequate reaction by macrophages, whereas low neopterin values in the presence of bacteraemia and clinical symptoms of sepsis show a deleterious impairment of immune functions.