Diagnosis and Antimicrobial Therapy of Lung Infiltrates in Febrile Neutropenic Cancer Patients

Pneumonia in the neutropenic cancer patient

PURPOSE OF REVIEW

Pneumonia is the leading cause of death among neutropenic cancer patients, particularly those with acute leukaemia. Even with empiric therapy, case fatality rates of neutropenic pneumonias remain unacceptably high. However, recent advances in the management of neutropenic pneumonia offer hope for improved outcomes in the cancer setting. This review summarizes recent literature regarding the clinical presentation, microbiologic trends, diagnostic advances and therapeutic recommendations for cancer-related neutropenic pneumonia.

RECENT FINDINGS

Although neutropenic patients acquire pathogens both in community and nosocomial settings, patients' obligate healthcare exposures result in the frequent identification of multidrug-resistant bacterial organisms on conventional culture-based assessment of respiratory secretions. Modern molecular techniques, including expanded use of galactomannan testing, have further facilitated identification of fungal pathogens, allowing for aggressive interventions that appear to improve patient outcomes. Multiple interested societies have issued updated guidelines for antibiotic therapy of suspected neutropenic pneumonia. The benefit of antibiotic medications may be further enhanced by agents that promote host responses to infection.

SUMMARY

Neutropenic cancer patients have numerous potential causes for pulmonary infiltrates and clinical deterioration, with lower respiratory tract infections among the most deadly. Early clinical suspicion, diagnosis and intervention for neutropenic pneumonia provide cancer patients' best hope for survival.

Utility of bronchoalveolar lavage fluid galactomannan alone or in combination with PCR for the diagnosis of invasive aspergillosis in adult hematology patients: a systematic review and meta-analysis

BACKGROUND

The clinical utility of bronchoalveolar lavage (BAL) fluid galactomannan (GM) for the early diagnosis of invasive aspergillosis (IA) varies widely across studies mainly due to heterogeneity of the studied populations.

METHODS

We conducted a systematic review and meta-analysis of 16 studies involving 783 adults with hematological malignancies to derive summary estimates of the overall accuracy of BAL-GM for diagnosing IA.

FINDINGS

Summary estimates of BAL-GM using an optical density (OD) index cutoff value of 1.5 for proven and probable IA were: sensitivity 0.92 (95% CI = 0.48-0.99), specificity 0.98 (95% CI = 0.78-1.00), positive likelihood ratio 53.7 (95% CI = 3.7-771.8), and negative likelihood ratio 0.08 (95% CI = 0.01-0.83). Comparing serum GM and Aspergillus PCR testing on BAL fluid, BAL-GM conferred greater sensitivity, but lower specificity than the serum GM test, and similar specificity as the PCR assay. The use of BAL-GM with serum GM or BAL-PCR tests increased the sensitivity moderately when a positive result was defined by either assay.

INTERPRETATION

GM quantification in BAL fluid at an OD index cutoff value of 1.5 has excellent sensitivity and specificity to assist clinical decision-making in confirming or excluding a diagnosis of IA when results are interpreted with clinical findings. Additional research investigating the effects of antifungal agents, optimal timing and processing of BAL sampling are needed to improve the diagnostic accuracy of BAL-GM testing.

Infektionen

Die Meldung und Erfassung von Infektionskrankheiten ist in Deutschland durch das Infektionsschutzgesetz (IfSG) geregelt. In §6 sind meldepflichtige Krankheiten nach gewissen Vorgaben geregelt.

Bis(methyl)gliotoxin proves to be a more stable and reliable marker for invasive aspergillosis than gliotoxin and suitable for use in diagnosis

The virulence factor gliotoxin (GT) and its inactive derivative, bis(methylthio)gliotoxin (bmGT), are produced by pathogens of the genus Aspergillus. Here we report the detection of GT and bmGT in serum of humans at risk of invasive aspergillosis (IA) as well as in cultures of fungal isolates derived from patients with proven infection with A. fumigatus. Although both compounds are readily recoverable from spiked human serum or plasma, only bmGT is retained in whole blood, indicating that bmGT may be the better marker for in vivo detection. Accordingly, bmGT was found more frequently than GT in samples from patients at risk of IA and incultures of clinical isolates of A. fumigatus. In some cases, bmGT was detected before mycologic evidence ofinfection was gained. Importantly, neither GT nor bmGT was found in serum from healthy donors or from neutropenic patients without any sign of infection. Thus, bmGT presence might provide a more reliable indicator of A. fumigatus infections than GT. Due to its simplicity and sensitivity, a diagnostic technology based on this test could be easily adopted in clinical laboratories to help in the diagnosis of this often fatal fungal infection.