[Use of procalcitonin and C-reactive protein as infection markers in febrile neutropenic patients undergoing haematopoietic stem cell transplant]

Abstract

Introduction and objective: Neutropenia is a frequent sign in patients who are going to have a haematopoietic stem cell transplant (HSCT). Infection is an important complication in these patients, which is favoured by immunosuppression and the degree of neutropenia. This study aims to evaluate the diagnostic usefulness of procalcitonin (PCT) and C-reactive protein (CRP) in onco-haematological patients undergoing chemotherapy and HSCT to determine the origin of the fever.

Patients and methods: PCT and CRP values were measured in 30 episodes of febrile neutropenia: before starting chemotherapy, appearance of neutropenia, onset of fever, days 1, 2, 3 and 6 after the onset of fever, and when the febrile episode ended. The episodes were classified as 5 bacteraemia, 3 microbiologically documented infections, 10 clinical infections, and 12 fevers of unknown origin.

Results: The highest PCT mean values corresponded to the group of patients with bacteraemia. Statistically significant differences (P=.04) were found on the second day after the onset of fever. The cut-off point of 0.5ng/ml showed a sensitivity of 66% and a specificity of 75%. PCR results showed statistically significant differences on days 1, 2 and 3 after the onset of fever (P=.01, P=.003, and P=.002, respectively). The cut-off point of 7.5mg/L had a sensitivity of 88% and a specificity of 58%.

Conclusions: The combination of PCT and CRP is an insufficient method to detect bacterial infections and may not replace the proper clinical and microbiological diagnosis.

Keywords: C-reactive protein; Febrile neutropenia; Neutropenia febril; Procalcitonin; Procalcitonina; Proteína C reactiva.