PROCALCITONIN AS A PROGNOSTIC MARKER IN TRANSPLANT PATIENTS HOSPITALIZED WITH SUSPECTED INFECTION IN A TERTIARY HOSPITAL

Infectious complications are frequent among solid organ and bone marrow transplant recipients. When uncontrolled, they can progress to sepsis and septic shock, a severe condition with mortality up to 70%. Early diagnosis in transplant patients is challenging due to immunosuppressive therapy, which masks clinical signs. Therefore, markers such as procalcitonin (PCT) have been studied to detect severe bacterial infections and anticipate interventions in high-risk patients. The aim of this study was to evaluate PCT as a prognostic marker in transplant patients with suspected bacterial infection and its association with progression to septic shock. Retrospective, quantitative cohort study including renal, liver, lung, heart, and bone marrow transplant recipients with PCT > 0.5 ng/mL, hospitalized in a tertiary transplant center between January 2020 and December 2022. Patients were followed for 14 days after PCT peak. After excluding cases with septic shock, recent trauma, anti-thymocyte globulin use, thyroid cancer, and non-bacterial infectious syndromes, 105 events remained for analysis. Of the 105 events, 72.4% occurred in men, with a mean age of 51.1 years and a mean Charlson comorbidity index of 5.2. Median PCT in the cohort was 2.2 ng/mL. Twenty-five patients (23.8%) progressed to septic shock, mostly male and kidney transplant recipients (52%). In this group, median PCT was 3.5 ng/mL, significantly higher than in the group with favorable outcomes (p = 0.01). The ROC curve showed an area under the curve of 0.669 (p < 0.05), with the best cutoff at 3.05 ng/mL (sensitivity 60%; specificity 73.8%). Comorbidities, age, and renal replacement therapy were not associated with progression to septic shock. Time since transplant (< 6 months) was also not statistically significant. PCT proved useful in predicting progression to septic shock in transplant patients. The lack of association with other clinical variables reinforces its relevance as a biomarker. Despite methodological limitations, the study highlights the importance of PCT as a prognostic tool and indicates the need for further studies.