Empirical antimicrobial treatment for chemotherapy-induced febrile neutropenia

Stenotrophomonas maltophilia: emerging disease patterns and challenges for treatment

Stenotrophomonas maltophilia is a ubiquitous organism associated with opportunistic infections. In the immunocompromised host, increasing prevalence and severity of illness is observed, particularly opportunistic bloodstream infections and pneumonia syndromes. In this article, the classification and microbiology are outlined, together with clinical presentation, outcomes and management of infections due to S. maltophilia. Although virulence mechanisms and the genetic basis of antibiotic resistance have been identified, a role for standardized and uniform reporting of antibiotic sensitivity is not defined. Infections due to S. maltophilia have traditionally been treated with trimethoprim-sulfamethoxazole, ticarcillin-clavulanic acid, or fluoroquinolone agents. The use of combination therapies, newer fluoroquinolone agents and tetracycline derivatives is discussed. Finally, measures to prevent transmission of S. maltophilia within healthcare facilities are reported, especially in at-risk patient populations.

Evidence-based guidelines for empirical therapy of neutropenic fever in Korea

Neutrophils play an important role in immunological function. Neutropenic patients are vulnerable to infection, and except fever is present, inflammatory reactions are scarce in many cases. Additionally, because infections can worsen rapidly, early evaluation and treatments are especially important in febrile neutropenic patients. In cases in which febrile neutropenia is anticipated due to anticancer chemotherapy, antibiotic prophylaxis can be used, based on the risk of infection. Antifungal prophylaxis may also be considered if long-term neutropenia or mucosal damage is expected. When fever is observed in patients suspected to have neutropenia, an adequate physical examination and blood and sputum cultures should be performed. Initial antibiotics should be chosen by considering the risk of complications following the infection; if the risk is low, oral antibiotics can be used. For initial intravenous antibiotics, monotherapy with a broad-spectrum antibiotic or combination therapy with two antibiotics is recommended. At 3-5 days after beginning the initial antibiotic therapy, the condition of the patient is assessed again to determine whether the fever has subsided or symptoms have worsened. If the patient's condition has improved, intravenous antibiotics can be replaced with oral antibiotics; if the condition has deteriorated, a change of antibiotics or addition of antifungal agents should be considered. If the causative microorganism is identified, initial antimicrobial or antifungal agents should be changed accordingly. When the cause is not detected, the initial agents should continue to be used until the neutrophil count recovers.

Efficacy and safety of linezolid in immunocompromised children with cancer

BACKGROUND

The aim of this study was to determine the safety, tolerance and efficacy of linezolid for the treatment of infections from Gram-positive bacteria in immunocompromised children with cancer.

METHODS

This was a prospective non-comparative unblinded study in the Hematology/Oncology Unit over a two-year period, administering linezolid as monotherapy in children with cancer.

RESULTS

Seventeen children received linezolid (30 mg/kgr: 3 i.v. per day). Mean duration of linezolid administration was 12.2 days (range, 6-38 days), while the median age of the evaluable patients was 2.2 years (range, 6 months-11.2 years). Primary diagnosis was acute lymphoblastic leukemia (nine patients), brain tumor (three patients), multi-organ Langerhans cell histiocytosis (two patients), rhabdomyosarcoma, Burkitt's lymphoma and ovarian tumor (one patient each). All patients were in the midst of chemotherapy cycles. Ten out of 17 children had positive blood cultures (methicillin-resistant Staphylococcus aureus, four patients; vancomycin-resistant Enterococcus, three patients; penicillin-resistant Streptococcus pneumoniae, three patients), while seven of the 17 had fever and vancomycin-resistant Enterococcus in stool cultures. All patients were considered clinically cured after the end of the linezolid regimen (100% efficacy). The main adverse events were thrombocytopenia grade 1-3 and anemia grade 2-3 (four and two patients, respectively). Chemotherapy-induced myelotoxicity (six patients) was not worsened during linezolid therapy. No bleeding episodes were presented. Self-limited diarrhea grade 1-2 was presented in four patients (mean duration 2 days). The total adverse event rate was 23.5%; however, there was no premature cessation of linezolid in any patient.

CONCLUSIONS

Linezolid may be another effective and safe therapy to treat infections from resistant Gram-positive bacteria in immunocompromised children, even in young ages.

Antibiotic management of febrile neutropenia: current developments and future directions

Mortality due to febrile neutropenia has decreased since the concept of empiric therapy became standard care. However, infectious complications remain the most common adverse events of chemotherapy. bacterial epidemiology has changed during the past decades. There is currently an increasing trend in infections due to Gramnegative bacteria which have higher rates of resistance for a variety of reasons.The use of biomarkers for diagnosis remains a domain of further investigation. Since the patient population with febrile neutropenia is very heterogeneous, models of risk assessment have been developed with the most commonly used today being the mASCC score.Oral antibiotic treatment seems to be appropriate in low-risk patients. In moderate or high-risk patients monotherapy is the most common option. However, due to emerging resistance this could change by next year. Some new antibiotics have been developed, but experience in the treatment of neutropenic fever is limited. The use of antibiotics for prophylaxis remains controversial, although recent studies suggest a reduction in death from all causes.

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

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.

Predicting survival in adults with invasive aspergillosis during therapy for hematological malignancies or after hematopoietic stem cell transplantation: Single-center analysis and validation of the Seattle, French, and Strasbourg prognostic indexes

In this retrospective monocenter study, we analyzed the outcomes of 130 adult hematological patients who developed a proven (n = 23), probable (n = 71), and possible (n = 36) invasive aspergillosis (IA) in a 13-year period. Forty-nine patients (38%) were recipients of an allogeneic hematopoietic stem cell transplantation (AlloHSCT). The main goal of the study was the identification of prognostic factors for 4-month aspergillosis free survival (AFS) and overall survival (OS). IA was identified as the main cause of death in 27/49 recipients of an AlloHSCT (55%) and 28/81 nontransplanted patients (35%). Diagnosis of IA at or before 2000 had a negative impact in both 4-month AFS and 4-month OS in the entire group. In multivariate analysis performed separately for nontransplanted and allo-HSCT patients, five variables (excluding the year of diagnosis) decreased 4-month AFS: (i) impairment of one organ function (OF), (ii) impairment of two or more OFs (two points), (iii) disseminated IA, (iv) neutropenia lasting more than 10 days (non-AlloHSCT group only) or monocytopenia (<0.1 x 10(9)/l) [AlloHSCT group only], and (v) high-dose steroids (non-AlloHSCT group only) or an alternative donor (AlloHSCT group only). According to the number of adverse risk factors, three prognostic subgroups were defined in non-transplanted and alloHSCT patients with good (97% and 78% AFS), intermediate (73% and 32% AFS) and poor prognosis (20% and 11% AFS) of IA [P < 0.01]. In addition, we validated the French and Seattle prognostic indexes for allo-HSCT recipients and the Strasbourg model for all hematological patients with IA.

Expression of CD11b/CD18 adhesion molecules on circulating phagocytes-a novel aid to diagnose infection in patients with cancer

GOALS OF WORK

No blood marker available to date is useful for distinguishing infection-related from neoplasm-related fever. We evaluated the expression of the peripheral blood phagocyte CD11b/CD18 adhesion molecule complex for this purpose.

MATERIALS AND METHODS

Neutrophil and monocyte CD11b/CD18 expression was assessed in two cohorts of patients with advanced solid cancer (n = 120) and in healthy controls (n = 63). The cancer series included 89 patients with verified infection, 23 without infection, and eight with neoplastic fever. CD11b/CD18 expression was measured using flow cytometry, and serum C-reactive protein (CRP) concentration was determined with immunoturbidimetric assay.

RESULTS

Cancer patients with infection had higher blood neutrophil and monocyte CD11b/CD18 expression levels than patients with neoplastic fever, those with advanced cancer without infection, or healthy controls (p < 0.01 for all analyses). High CD11b/CD18 values were measured exclusively in individuals diagnosed with infection. Receiver-operating characteristic area under the curve (AUC) for neutrophil and monocyte CD11b/CD18 expression for the discrimination of infection from neoplastic fever was 0.80 (95% CI, 0.70 to 0.88), which was superior (p = 0.039 and p = 0.049, respectively) to serum CRP on admission (AUC 0.51, 0.40 to 0.62).

CONCLUSIONS

Peripheral blood phagocytic cell CD11b/CD18 expression is useful for making a differential diagnosis between infection and neoplasm-related fever in cancer patients.