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Background: The etiology of bacteremia in hematological patients with febrile neutropenia differs geographically and changes over time. Since efficient empirical antibiotic treatment depends on relevant knowledge of the bacterial panorama, the aim of this study was to describe the prevalence of bacteremia, the bacterial spectrum, and the resistance patterns of the isolates in this group today. Methods: In a cross-sectional study, routine blood cultures from febrile episodes occurring in adult patients with hematological disorders and neutropenia presenting to Karolinska University Hospital, Stockholm, Sweden during a 24-month period, were analyzed. Results: A total of 142 febrile neutropenic episodes occurring in 124 hematological patients were included in the study. Bacteremia was documented in 27% of the episodes, and of these, 58% were due to Gram-positive pathogens. The most common isolates were viridans streptococci, coagulase-negative staphylococci, and Escherichia coli. Low levels of antibiotic resistance were detected. The underlying diagnosis of non-Hodgkin's lymphoma (NHL) was independently negatively associated with documented bacteremia ( p < 0.01). Conclusions: The prevalence of bacteremia and the bacterial spectrum were consistent with recent Scandinavian reports. Substantially lower levels of antimicrobial resistance were registered compared to those found in other European centers. Patients with NHL were less likely to have documented bacteremia in this study. [ABSTRACT FROM AUTHOR]

This study was performed to analyse differences in T-cell proliferation induced by a latent virus, varicellae-zoster virus (VZV) and a non-latent virus, measles virus, in patients after allogeneic bone marrow transplantation (BMT). The lymphoproliferative response to measles antigen, VZV-antigen (VZV-ag), and phytohemagglutinin (PHA) was measured by 3H-thymidine incorporation, and interferon-γ (IFN-γ) and interleukin-10 (IL-10) analyses in supernatants after in vitro stimulation of peripheral blood mononuclear cells (PBMC) from 22 patients and 18 healthy controls. The cytokine levels were correlated with T-cell subsets by FACS analyses. At the antigen concentrations used, VZV-ag induced higher levels of IFN-γ (p<0.05) than did the measles antigen, whereas the levels of IL-10 were similar. Patients without a cell mediated immune (CMI) response to VZV-ag or measles antigen had lower CD4+T-cell counts than did controls (p<0.01 in both cases) and lower IFN-γ production after non-specific PHA stimulation (p<0.01). The IFN-γ and IL-10 levels after measles antigen stimulation correlated with the number of CD4+ T-cells (p<0.01 and p<0.05, respectively), and after VZV-ag mainly to the number of CD8+T-cells (p<0.01 and p<0.05, respectively). These results suggest that there is a difference in the types of T-cells that respond to VZV-ag and measles antigen stimulation, respectively. The impaired CMI response to viral antigens seen in many patients may be explained both by a low number of CD4+ T-cells and by a cell dysfunction. [ABSTRACT FROM AUTHOR]

Both CMV and fungal infections have been suggested to be causes of fever of unknown origin (FUO) in neutropenic patients. The aim of this prospective, blinded study was to use nucleic acid techniques for monitoring of 20 acute leukemia and 15 autologous stem cell transplant (SCT) patients. Blood samples were taken weekly and examined for fungal and CMV DNA by PCR and CMV mRNA by NASBA. 387 samples were analysed. Fungal DNA was detected in 9 samples. Four samples were positive for Aspergillus and 6 for Candida DNA (1 sample positive for both). Candida PCR was positive in 2 patients with FUO, 1 patient with a bacterial infection, 1 patient with fungaemia, and in 1 afebrile patient. Three patients had verified Candida infections. One was PCR positive and 2 were negative. Three patients with positive Aspergillus PCR had pneumonias and 1 patient had a FUO. CMV DNA was found in 19 samples from 15 CMV seropositive patients. CMV mRNA was detected in 1 sample. Two patients had infections possibly caused by CMV. No antiviral therapy was give and both recovered. PCR for Aspergillus might be helpful for the diagnosis of pneumonia while neither CMV nor Candida PCR conferred diagnostic benefits in this study.