[Procalcitonin. A new marker for bacterial infection]

Procalcitonin is a polypeptide present in the plasma of healthy subjects in minimal levels (< 0.5 ng/ml). Serum procalcitonin is markedly increased a few hours after the administration of endotoxin to human volunteers and in invasive bacterial infection (sepsis, septic shock, meningitis). Procalcitonin is moderately increased in local bacterial infection (pneumonia pyelonephritis) and is unchanged in viral infections or bacterial colonization. Procalcitonin is increased in serious bacterial infections in neonates, children and adults and is currently the best diagnostic marker of severe bacterial infection, being better than leukocyte, interleukin or C-reactive protein counts. C-reactive protein levels can be normal in severe sepsis and some viral infections. We studied 54 children with sepsis in whom plasma procalcitonin levels showed a positive correlation with the vasoactive drugs necessary to maintain cardiovascular activity. The semiquantitative procalcitonin test is simple and easy to use at the bedside at any time and in any hospital as no instruments are required. Within 30 minutes, the test identifies the type of infection and whether antibiotics are indicated.