Antimicrobial therapy as a part of the decontamination procedures for patients with acute leukemia

Effectiveness of antibacterial prophylaxis in children with acute leukemia: A report from a single institution over a 20-year period

BACKGROUND

Infection is the major cause of treatment-related mortality in childhood acute leukemia, mainly due to bacterial translocation across the intestinal mucosa. Only a few studies have reported the impact of different antibacterial prophylaxis treatments on digestive tract flora and infection-related mortality.

PROCEDURES

We performed a retrospective analysis of two different digestive tract decontamination modalities (selective or total digestive decontamination) in a large single-center series of 323 children during the induction treatment of acute leukemia between January 1995 and December 2014. We examined the impact of antibiotic prophylaxis and food regimen (sterile or selected) on the digestive tract flora during the period of antibacterial prophylaxis, on the frequency of bacteremia, and on antibiotic sensitivity.

RESULTS

Only one Gram-negative (Klebsiella pneumonia) translocation occurred in the SDD group. No infection-related death occurred. Extended-spectrum beta-lactamase (ESBL) bacteria were observed in seven of 170 (4%) patients in the SDD group. The faecal-flora total suppression and faecal-flora Gram-negative bacilli suppression was 67 and 77%, respectively, in the TDD group with sterile food, 0 and 58%, respectively, in the SDD group with sterile food, and 6 and 63%, respectively, in the SDD group with selective food.

CONCLUSIONS

This study gives a rationale not to use antibacterial prophylaxis systematically in children who receive induction treatment for acute leukemia; additionally, antibiotics should only be used in case of stool contamination by highly pathogenic bacteria with a high potential of translocation.

Antiproliferative and Apoptosis Triggering Potential of Paclitaxel-Based Targeted-Lipid Nanoparticles with Enhanced Cellular Internalization by Transferrin Receptors-a Study in Leukemia Cells

Leukemia is a typical blood cancer that is characterized by the numerous duplication and proliferation of white blood cells. The main aim of this study was to develop PTX-loaded multifunctional nanoparticles and target to leukemia cells. In this study, transferrin-decorated paclitaxel-loaded lipid nanoparticle (TPLN) was prepared with an aim to increase the chemotherapeutic efficacy in the leukemia cells. Results clearly showed the superior targeting potential of TPLN to the HL-60 cancer cells compared to that of the paclitaxel-loaded nanoparticles (PLN). To be specific, TPLN showed a significantly higher cytotoxic effect in the cancer cells compared to that of the PLN indicating the superior targeting efficiency of the Tf-decorated nanoparticle system. The IC50 value of TPLN was 0.45 μg/ml compared to 2.8 μg/ml for PLN. TPLN induced a most remarkable apoptosis of the cancer cells and much of the cells were distorted with huge presence of the apoptotic body formation. Importantly, TPLN showed a remarkable reduction in the viable cells proportion to ~ 65% with around ~ 30% apoptosis cells (early and late apoptosis). Overall, results clearly showed the targeting potential of ligand-conjugated lipid nanoparticle system to the leukemia cells that might pave the way for the successful cancer treatment.

Aptamer-Functionalized Fluorescent Silica Nanoparticles for Highly Sensitive Detection of Leukemia Cells

A simple, highly sensitive method to detect leukemia cells has been developed based on aptamer-modified fluorescent silica nanoparticles (FSNPs). In this strategy, the amine-labeled Sgc8 aptamer was conjugated to carboxyl-modified FSNPs via amide coupling between amino and carboxyl groups. Sensitivity and specificity of Sgc8-FSNPs were assessed using flow cytometry and fluorescence microscopy. These results showed that Sgc8-FSNPs detected leukemia cells with high sensitivity and specificity. Aptamer-modified FSNPs hold promise for sensitive and specific detection of leukemia cells. Changing the aptamer may allow the FSNPs to detect other types of cancer cells.

Host impairments in patients with neoplastic diseases

Healthy individuals possess an immune system comprising physical barriers, innate and acquired immunity as well as the indigenous microflora that populate the body surfaces. The immune system maintains constant vigilance over the body at the cellular level as well as at the interface between the host integument and the resident microflora. However, neoplastic diseases and their treatment often lead to impaired immunity resulting in an increased risk of infections due to viruses, bacteria, fungi, and protozoa. This chapter explores the various aspects of host impairment focusing on the components of immunity and the interplay between them to explain why it is that these patients succumb to infections per se. In so doing, we hope that the reader will be better equipped to understand the risks patients face so as to anticipate potential infectious complications and implement appropriate measures to help attain successful remission of the neoplastic diseases and maintain the best quality of life for the patient.

Reflections on gut decontamination in hematology

In Europe, but decontamination (GD) is largely used in the prophylaxis of bacterial infections in departments of oncohematology treating neutropenic patients, in particular those patients subject to profound (absolute neutrophil count (ANC) <100/mm3) and prolonged (>10 days) neutropenia, such as patients undergoing bone marrow allografting or induction chemotherapy for acute leukemia. Initially, treatment was in the form of non-absorbable antibiotics, but this has been partially superseded by quinolone-containing regimens, in particular in the centers participating in EORTC trials. In the last two EORTC trials comparing different regimens for the treatment of febrile neutropenia, 57-73% of the patients were receiving GD. A French epidemiologic study, performed prospectively and consecutively in 36 oncohematology centers, has recently shown that 45% of febrile neutropenic patients receive digestive decontamination (DD) at the onset of their first febrile episode. The value of GD has been the subject of much controversy. Numerous trials, some of which were controlled, were performed in neutropenic patients in the 1980s, prior to trials of GD in intensive care units, but did not lead to a consensus in the medical community of the value of GD. Moreover, GD is not, or is infrequently, used in the USA. Apart from trials involving the quinolones, very few studies have been published during the last 10 years. Despite this, policies have not changed greatly in the various centers. The CLIOH group has gathered the opinions of experts invited to a multidisciplinary meeting that took place in Paris in October 1996. The text that follows summarizes the reflections arising from this forum. It should be noted that this meeting was not designed to be a consensus conference, but rather to re-examine the correlation between the data in the literature and actual clinical practice and to highlight the main problems posed by DD in current oncohematology. The experts were separated into three working groups, each of which has drafted a report which appears in the text below.

Infection in acute leukemia patients receiving oral nonabsorable antibiotics

During a 20-month period all acute nonlymphocytic patients (87 patient trials) receiving cytotoxic chemotherapy were placed on an oral nonabsorbable antibiotic regimen consisting of gentamicin, vancomycin, and nystatin in addition to an intensive program of infection prevention aimed at reducing exogenously acquired and body-surface potential pathogens. Although side effects of anorexia, diarrhea, and nausea were common, gentamicin-vancomycin-nystatin was ingested 80% of the study time. Microbial growth in gingival and rectal cultures was substantially reduced. The incidence of bacteremias and other serious infections was low. Pseudomonas aeruginosa, other gram-negative bacilli, and Candida species caused few infections along the alimentary canal, whereas infections of the skin (especially Staphylococcus aureus) were not reduced compared with those occurring in former years. A total of the 104 acquired gram-negative bacilli were gentamicin resistant; 5 subsequently caused infection. Thus, despite certain definite drawbacks, the use of oral nonabsorbable antibiotics to suppress alimentary tract microbial flora in combination with other infection prevention techniques in granulocytopenic cancer patients has proven feasible and tolerable and has been associated with a low order of life-threatening infections.