Diagnostic value of serum procalcitonin and C-reactive protein for infections after allogeneic hematopoietic stem cell transplantation versus nontransplant setting

Objective Procalcitonin (PCT) has been increasingly used as a biomarker of infection. The purpose of this study was to evaluate its diagnostic value after hematopoietic stem cell transplantation (HSCT), where noninfectious febrile complications such as graft-versus-host disease frequently develop. Methods We retrospectively analyzed 144 febrile episodes (infections: 82, and noninfections: 62) in adult patients with hematological disorders, including 57 and 87 episodes in HSCT and non-HSCT patients, respectively. Results Of 57 febrile episodes in HSCT patients, 46 (86%) and 25 (44%) revealed positivity for C-reactive protein (CRP) and PCT, respectively. Among 87 febrile episodes in non-HSCT patients, 81 (93%) and 22 (25%) events showed positive results of CRP and PCT. Both of these biomarkers were associated with infectious episodes in univariate analysis. Multivariate analysis showed that a high cut-off level (>9.5 mg/dL) of CRP was a better indicator for infections than PCT in HSCT patients, while PCT positivity was more diagnostic for infections than any cutoff CRP level in non-HSCT patients. Conclusion It may be necessary to interpret the results of these biomarkers with different orders of priority in transplant versus nontransplant patients.