Abstract
Neopterin is regarded as an early biomarker of the cellular immune response. This low molecular mass compound belongs to the class of pteridine and is a metabolite of guanosine triphosphate, which is produced by the activated macrophages and dendritic cells after stimulation with gamma-interferon. An international group acknowledges the fact that the levels of serum neopterin can be used as a marker of the effect of exposure to silica and other occupational diseases. The determination of neopterin is an innovative tool for monitoring diseases associated with the activation of cell-mediated immunity.