Simple dipstick assay for semi-quantitative detection of neopterin in sera

Neopterin, a low-molecular-mass pteridine produced by macrophages, is closely associated with activation of the cellular immune system. Neopterin biosynthesis during inflammatory disease is primarily derived from interferon-activated monocytes/macrophages and neopterin concentrations may be significantly increased in a particular disease state compared to controls. A follow-up of serum neopterin concentrations during the course of an infectious disease could be useful for measuring the activity of the disease and the influence of treatment. We have developed a simple dipstick assay for the semi-quantitative detection of the neopterin concentration in the serum of patients during the course of an infectious disease. Assay performance was comparable to an ELISA, but there is no requirement for specialised equipment.