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

The aim of the study was to investigate the reliability of procalcitonin (P CT), a new potential marker for detection of bacterial, fungal and protozoa l infections, in order to differentiate these from viral infections and ear ly rejections in heart, heart-lung and lung transplanted patients. PCT is a propeptide of calcitonin with unknown origin which is not detectable in pl asma of healthy subjects. It increases rapidly and significantly under seve re microbial infections. Methods: PCT plasma levels were measured using an immune-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 we re clearly associated with the severity of the infection. Trauma of operati on or inflammatory events such as viral infections and rejections did not t rigger POT-production The release of PCT did not depend on the type of path ogens even though Aspergillum resulted in the highest levels measured. Sens itivity, specificity and prognostic value of PCT for systemic infections we re higher than of the other parameters investigated. Conclusion: PCT is a highly specific analyte which shows significant diagno stic Validities when nonviral infections are compared with rejection episod es. PCT discriminates between inflammatory events such as rejection or vira l infections and nonviral-infections including bacterial, fungal and protoz oal 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.