Diagnostic value of PCR analysis of bacteria and fungi from blood in empiric-therapy-resistant febrile neutropenia

Abstract

This study aimed to assess the clinical utility of PCR for the analysis of bacteria and fungi from blood for the management of febrile neutropenic patients with hematologic malignancies. Using a PCR system able to detect a broad range of bacteria and fungi, we conducted a prospective pilot study of periodic analyses of blood from patients following intensive chemotherapy. When fever occurred, it was treated with empirical antibiotic therapy, basically without knowledge of the PCR results. In 23 febrile episodes during the neutropenic period, bacteria were detected by PCR in 11 cases, while the same species were identified by blood culture in 3 cases. In 10 out of 11 PCR-positive cases, fever could be managed by empirical therapy. In the empirical-therapy-resistant case, the identification of Stenotrophomonas maltophilia by PCR led to improvement of fever. No fungi were detected by PCR in febrile cases, while Aspergillus fumigatus was detected in one afebrile patient, several days before a clinical diagnosis was made. In subsequent sporadic PCR analyses in 15 cases of febrile neutropenia, bacteria were detected by both PCR and blood culture in 7 cases and by PCR alone in 6. Fungi were not detected. While fever was improved by empirical therapy in 12 out of the 13 PCR-positive cases, the identification of Pseudomonas aeruginosa by PCR in one therapy-resistant case contributed to the successful treatment of persistent fever. Our results indicate that PCR analysis of bacteria from blood provides essential information for managing empirical-therapy-resistant febrile neutropenia.

FIG. 1.

A case of empirical therapy-resistant PCR-positive febrile neutropenia. A 64-year-old female with acute myeloid leukemia (M2) had an episode of fever during the nadir period after consolidation chemotherapy. Empirical therapy with cefepime (FEP) and meropenem (MEM) was ineffective. Because PCR results disclosed that S. maltophilia had been detectable from the first day of fever, minocycline (MIN) was added to the therapy. Thereafter, her fever subsided and S. maltophilia became undetectable. BT, body temperature; CRP, C-reactive protein; N.A., not applicable.

FIG. 2.

A case of empirical-therapy-effective PCR-positive febrile neutropenia. A 24-year-old male with acute myelomonocytic leukemia (M5a) had an episode of fever during the nadir period of reinduction chemotherapy. Empirical therapy with cefepime (FEP) was effective. K. oxytoca had been PCR positive for more than 10 days from the first day of fever and became undetectable after therapy.