Procalcitonin and Neopterin in Infectious Diseases

Abstract

SummaryProcalcitonin, a new inflammation parameter, has been shown to be markedly increased in patients with severe bacterial and parasitic infections, septic shock, and multiple organ failure. In contrast, in severe viral infections or inflammatory reactions of non-infectious origin (e.g. toxic acute respiratory distress syndrome or toxic pancreatitis) as well as in autoimmune disorders, there is little or moderate increase of procalcitonin serum levels. Therefore procalcitonin may be used for diHerential diagnosis of bacterial versus non-bacterial inflammation. Furthermore, procaicitonin correlates with the severity of infection and sepsis and it is considered to be a valid parameter t()r monitoring both the severity and the course of sepsis and multiple organ failure as well as the success of surgical ~lI1d intensin.' therapy in critically ill patients. Neopterin production is closely associated with activation of the celluLll' immune sYstem. High neopterin levels are found in several inflamlnatory diseases and certain malignancies. ~eopterin me~lsurements are usehll for monitoring allograft recipients to detect immunological c0111plicltions. In autoimmune diseases, neopterin concentrations reflect the extent and activity of disease . In intl-crious dise~lscs, ncopterin helps in the differential diagnosis of acute viral and bacterial infections and provides prognostic intc)rmarion in human immunodeficiency virus disease and in patients with rnultiple trauma and sepsis. In this article the clinical application of procalcitonin and neopterin in infectious diseases is reyiewed, and special emphasis is given to clinical simarions in " 'hich the combined determination of both par~1l11ctcrs, neoprerin and procalcitonin, is able to suppon ditkrential diagnosis.

Involvement of Cyclic Adenosine Monophosphate-Dependent Protein Kinase A and Pertussis Toxin-Sensitive G Proteins in the Migratory Response of Human CD14+ Mononuclear Cells to Katacalcin

“…More recently, intracellular antibody reaction against KC supported the notion that various types of leukocytes may contain PCT, suggesting that KC, CT, and N‐ProCT may be more widely distributed than originally thought (10) . Circulating levels of PCT are low in healthy subjects, but when elevated levels were found in patients with bacterial infections, PCT became an important protein in the detection and differential diagnosis of inflammatory states (11,12) . C cells in the thyroid are not believed to be the source of bacterial infection‐induced PCT; probable sites of PCT production during inflammation are pulmonary and intestinal neuroendocrine cells, (11) and because of the association between increased levels of PCT and leukocyte‐derived cytokines during sepsis, the possible expression of PCT in human blood leukocytes has been investigated.…”

“…Circulating levels of PCT are low in healthy subjects, but when elevated levels were found in patients with bacterial infections, PCT became an important protein in the detection and differential diagnosis of inflammatory states (11,12) . C cells in the thyroid are not believed to be the source of bacterial infection‐induced PCT; probable sites of PCT production during inflammation are pulmonary and intestinal neuroendocrine cells, (11) and because of the association between increased levels of PCT and leukocyte‐derived cytokines during sepsis, the possible expression of PCT in human blood leukocytes has been investigated. PCT and CT were found to be expressed in those cells and their synthesis was modulated by bacterial lipopolysaccharide and sepsis‐related cytokines (10,13) .…”

Clinical Usefulness of Determining the Concentration of Neopterin

“…However, the ratio of CRP: neopterin is helpful in differential diagnosis: if the ratio of CRP (mg/L) to a concentration of neopterin (nmol/L) is greater than 1, bacterial infection is probable, whereas a value below 1 is characteristic for the viral etiology (33). Thus, serum neopterin can be used as a differentiating, monitoring and forecasting parameter in viral infections (4, 17,18,26,[48][49][50].…”

“…It is assumed that the concentration of neopterin corresponds with activity and severity of autoimmune process (48).…”

Evaluation of clinical usefulness of serum neopterin determination in children with bacterial infections

“…First observations concerning increased secretion of neopterin in people with diagnosed viral infections were made by coworkers in 1979 (Wachter et al, 1979). A number of other studies indicates that determination of neopterin concentration is a useful parameter in differentiating between viral and bacterial infections (Fuchs, 1998;Wiedermann et al, 1999;Murr et al, 2002).…”