Procalcitonin: a new marker for diagnosis of acute rejection and bacterial infection in patients after heart and lung transplantation

Abstract

The aim of the study was to investigate the reliability of procalcitonin (PCT), a new potential marker for detection of bacterial, fungal and protozoal infections, in order to differentiate these from viral infections and early rejections in heart, heart-lung and lung transplanted patients. PCT is a propeptide of calcitonin with unknown origin which is not detectable in plasma of healthy subjects. It increases rapidly and significantly under severe microbial infections.

Methods: PCT plasma levels were measured using an immuno-luminescence assay. C-reactive protein and white blood cells were quantified to validate the PCT values.

Results: Increased levels of PCT were found in all transplant patients with bacterial, fungal and protozoal infections. The magnitude of the values were clearly associated with the severity of the infection. Trauma of operation or inflammatory events such as viral infections and rejections did not trigger PCT-production. The release of PCT did not depend on the type of pathogens even though Aspergillum resulted in the highest levels measured. Sensitivity, specificity and prognostic value of PCT for systemic infections were higher than of the other parameters investigated.

Conclusion: PCT is a highly specific analyte which shows significant diagnostic validities when nonviral infections are compared with rejection episodes. PCT discriminates between inflammatory events such as rejection or viral infections and nonviral-infections including bacterial, fungal and protozoal infections. The half-life of PCT is 24 h indicating clearly a competent antibiotic treatment. Unnecessary antibiotic therapy can be avoided due to the early exclusion of bacterial and fungal infections.