Diagnostic value of procalcitonin in transplant patients receiving immunosuppressant drugs: A retrospective electronic medical record-based analysis

Objectives: To evaluate concentrations of procalcitonin (PCT) in transplant recipients receiving immunosuppressive therapy compared with nonimmunosuppressed patients. Methods: We analyzed a data set of 9,500 inpatient encounters to compare levels of PCT and other biomarkers of infection (C-reactive protein [CRP], WBC count, and absolute neutrophil count [ANC]) between immunosuppressed and nonimmunosuppressed cohorts. We also assessed the correlation between PCT and clinical variables in immunosuppressed patients. Results: Patients receiving immunosuppressive drugs had significantly higher levels of maximal and minimal PCT compared with the nonimmunosuppressed patients (P<.0001 and P=.0019, respectively). However, CRP levels, WBC count, and ANC were significantly lower in immunosuppressed patients compared with the nonimmunosuppressed patients (P=.0003, P<.0019, and P=.0001, respectively). Conclusions: Our results from real-world data demonstrated that PCT dynamics remain intact despite immunosuppressive therapy, in contrast to other biomarkers such as CRP, WBC, and ANC. In addition, higher PCT levels are associated with systemic infections and reflect disease severity.