A randomized trial on chlorhexidine dressings for the prevention of catheter-related bloodstream infections in neutropenic patients

BACKGROUND

Central venous catheter (CVC)-related bloodstream infections (CRBSI) are a frequent cause of morbidity and mortality in patients with chemotherapy-induced neutropenia. Chlorhexidine containing catheter securement dressings may prevent CRBSI.

PATIENTS AND METHODS

A multicenter randomized, controlled trial was conducted at 10 German hematology departments. We compared chlorhexidine-containing dressings with non-chlorhexidine control dressings in neutropenic patients. The primary end point was the incidence of definite CRBSI within the first 14 days (dCRBSI14) of CVC placement. Secondary end points included combined incidence of definite or probable CRBSI within 14 days (dpCRBSI14), overall (dpCRBSI), incidence of unscheduled dressing changes and adverse events.

RESULTS

From February 2012 to September 2014, 613 assessable patients were included in the study. The incidence of dCRBSI14 was 2.6% (8/307) in the chlorhexidine and 3.9% (12/306) in the control group (P = 0.375). Both dpCRBSI14 and dpCRBSI were significantly less frequent in the study group with dpCRBSI14 in 6.5% (20/307) of the chlorhexidine group when compared with 11% (34/306) in the control group (P = 0.047), and dpCRBSI in 10.4% (32/307) versus 17% (52/306), respectively (P = 0.019). The frequency of dressing intolerance with cutaneous and soft tissue abnormalities at the contact area was similar in both groups (12.4% and 11.8%; P = 0.901).

CONCLUSIONS

Although the trial failed its primary end point, the application of chlorhexidine containing catheter securement dressings reduces the incidence of definite or probable CRBSI in neutropenic patients.

CLINICAL TRIALS NUMBER

NCT01544686 (Clinicaltrials.gov).

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Reduced-toxicity conditioning with treosulfan, fludarabine and ATG as preparative regimen for allogeneic stem cell transplantation (alloSCT) in elderly patients with secondary acute myeloid leukemia (sAML) or myelodysplastic syndrome (MDS)

We investigated a dose-reduced conditioning regimen consisting of treosulfan and fludarabine followed by allogeneic stem cell transplantation (SCT) in 26 patients with secondary AML or MDS. Twenty patients were transplanted from matched or mismatched unrelated donors and six from HLA-identical sibling donors. The median age of the patients was 60 years (range, 44-70). None of the patients was eligible for a standard myeloablative preparative regimen. No graft-failure was observed, and leukocyte and platelet engraftment were observed after a median of 16 and 17 days, respectively. Acute graft-versus-host disease (GvHD) grade II-IV was seen in 23% and severe grade III GvHD in 12% of the patients. No patients experienced grade IV acute GvHD. Chronic GvHD was noted in 36% of the patients, which was extensive disease in 18%. The 2-year cumulative incidence of relapse was 21%. The relapse rate was higher in patients beyond CR1 or with intermediate two or high risk MDS (P = 0.02). The treatment-related mortality at day 100 was 28%. The 2-year estimated overall and disease-free survival was 36-34%, respectively. No difference in survival was seen between unrelated and related SCT.

[Tumor oxygenation in combined whole body hyperthermia and polychemotherapy. Studies exemplified by recurrent carcinoma of the mouth cavity]

BACKGROUND AND OBJECTIVE

Previous studies have reported synergistic effects of combined hyperthermia and chemotherapy and/or irradiation. The response to irradiation and chemotherapy of well-oxygenated and vascularized tumors generally is better than that of hypoxic tumors. Therefore, tumor oxygenation is recognized as an important predictive factor in the therapy of malignant tumors. In practice, the head and neck area remains outside of the hyperthermia chamber during whole-body hyperthermia. It was the aim of this study to evaluate if the head and neck region receives sufficient warmth and, if so, if tumor oxygenation increases accordingly.

PATIENTS/METHODS

Whole-body hyperthermia, as heat radiation (Enthermics Medical Systems RHS-7500), was applied to the narcotised 60-year-old male patient with a local recurrence tumor pT3 pN2b M0 squamous cell carcinoma of the oral cavity. Tumor oxygenation and temperature were measured by LICOX catheters via one-point measurement during the entire hyperthermia treatment (3.5 h). Parallelly, chemotherapy (ifosfamide/Carboplatin) was given in four cycles (one cycle/month).

RESULTS

With a latency of 10 min the increase of intratumoral temperature was comparable to temperatures achieved in the esophagus. The maximum intratumoral temperature was 41.8 degrees C. The average increase in tumor oxygenation was more than 100%. The clinical outcome in the case presented was a partial tumor remission (PR).

CONCLUSIONS

During combined whole-body hyperthermia and polychemotherapy, tumor oxygenation is also significantly improved in the head and neck area, despite the fact that the head and neck area remained outside the hyperthermia chamber. The intratumoral temperature was comparable to esophageal and rectal temperatures.

Reactive oxygen species as mediators of the transformed phenotype

Reactive oxygen species (ROS) are known to be involved in different pro- and anticarcinogenic mechanisms. However, their influence on the maintenance of the transformed phenotype has not been studied so far. Here we show that the anchorage-independent growth of transformed murine fibroblasts is inhibited by antioxidants and radical scavengers in a concentration-dependent and reversible manner. These agents also reduce TGF-beta-dependent stimulation of colony formation in soft agar, pointing to their specific interference with TGF-beta-triggered signal chains involved in the maintenance of the transformed state.

Fibroblasts transformed by chemical carcinogens are sensitive to intercellular induction of apoptosis: implications for the control of oncogenesis

The ability of neighbouring normal cells to inhibit proliferation of transformed cells is regarded as the classical mode of intercellular control of potential tumour cells. This mechanism, however, only controls the pool size of transformed cells, but does not impair their survival. We have recently shown that cells transformed by biological agents are subject to a novel control system: transforming growth factor beta (TGF-beta) induces normal cells to release factors that mediate apoptosis specifically in transformed cells. Here we show that cells transformed by chemical carcinogens are also subject to this dominant control mechanism. The number of foci induced by methylcholanthrene, N-methyl-N'-nitro-N-nitrosoguanidine or quercetin was significantly reduced when the cultures were treated with TGF-beta. Established lines of chemically transformed cells proved to be sensitive to induction of apoptosis by neighbouring normal cells in the presence of TGF-beta. This finding demonstrates that sensitivity to induction of apoptosis is a general feature of transformed cells, irrespective of the transforming agent. It is particularly relevant for chemical carcinogenesis. As transformed cells were shown to trigger induction of their own apoptosis, the acquisition of resistance to this process may be a central regulatory step in carcinogenesis in vitro and possibly also in vivo. This study may help to elucidate mechanisms that protect transformed cells at an early stage of tumour progression that has until now not been the focus of investigation.