Background: Allograft infection after lung transplantation has a significant impact on the procedure outcome and could be a diagnostic challenge. Pneumocystis jirovecii is an opportunistic infection causing life-threatening pneumonia (PCP) in immunocompromised patients. Airway colonisation with Pseudomonas aeruginosa is common in lung transplant (LTx) recipients. The aim of the study was to compare a retrospective case review of Pneumocystis jiroveci and Pseudomonas aeruginosa infections in lung transplant's (LTx) recipients and compare them with serum procalcitonin concentrations (PCT).
Material/Methods: 15 LTx patients were retrospectively involved into the study (10 men and 5 women, mean age: 41.4±14.6 yr.). In 7 patients cysts of P. jiroveci were diagnosed (group J) and in 13 patients P. aeruginosa (group A) was isolated. In respiratory samples P. jiroveci was detected using indirectimmunofluorescence method and P. aeruginosa was isolated using routine microbiological methods. PCT was measured using immunoluminescence assay (ILMA; BRAHMS PCT LIA, Berlin, Germany).
Results: Average PCT value in group A was 0.30±0.21 and in group J was 0.88±0.43, the difference was not significant. In group A 3 patients (23.1%) had PCT value indicating moderate infection risk (PCT >0.5) and 1 patient (7.7%) high infection risk (PCT >2.0 and <10). In group J 3 patients (42.9%) had PCT value indicating moderate and 1 patient (14.3%) high infection risk.
Conclusions: Bronchial tree colonization with Pneumocystis jiroveci as well as
Pseudomonas aeruginosa infection/colonization are associated with moderate
procalcitonin increase suggesting general systemic response, also during colonization of only bronchi of the transplanted lung.

Keywords: Lung Transplantation