996 resultados para amphotericin B


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Disseminated cryptococcal disease is typically seen in patients with HIV infection. We report here the evolution of a patient with disseminated cryptococcosis whose treatment failed after ten weeks of induction therapy with amphotericin B. This case illustrates the importance of careful initial evaluation, and close clinical follow-up of these patients who are at risk of developing other opportunistic infections and drug-related complications.

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Invasive fungal infections are frequent and severe complications in leukaemic patients with prolonged neutropaenia. Empirical antifungal therapy has become the standard of care in patients with persistent fever despite treatment with broad-spectrum antibiotics. For decades amphotericin B deoxycholate has been the sole option for empirical antifungal therapy. Recently, several new antifungal agents became available. The choice of the most appropriate drug should be guided by efficacy and safety criteria. The recommendations from the First European Conference on Infections in Leukaemia (ECIL-1) on empirical antifungal therapy in neutropaenic cancer patients with persistent fever have been developed by an expert panel after assessment of clinical practices in Europe and evidence-based review of the literature. Many antifungal regimens can now be recommended for empirical therapy in neutropaenic cancer patients. However, persistent fever lacks specificity for initiation of therapy. Development of empirical and pre-emptive strategies using new clinical parameters, laboratory markers and imaging techniques for early diagnosis of invasive mycoses are needed.

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OBJECTIVES: Caspofungin was evaluated as first-line monotherapy of invasive aspergillosis (IA) in patients with haematological malignancies and undergoing autologous transplants. METHODS: Adults with proven or probable IA, defined strictly according to EORTC-MSG criteria, were eligible. Those with possible IA were enrolled, but were not evaluable for efficacy unless upgraded to proven/probable disease within 7 days of registration based on investigations performed within 48 h after enrolment. Caspofungin dosage was 70 mg (day 1) followed by 50 mg/day. The primary endpoint was the proportion of patients with complete or partial response at the end of caspofungin therapy in the modified intention to treat (MITT) group; secondary endpoints were response and survival at day 84 and safety. RESULTS: In the MITT group (n = 61), 75% of patients had cancer not in remission (relapsing or refractory), 85% were neutropenic at enrolment and 49% had a Karnofsky score of < or =50. At end of treatment, 1 and 19 patients had complete and partial response, respectively [success rate 33% (20/61)], 9 (15%) achieved stabilization and 31 (51%) had disease progression. One patient was not evaluable. The 6 and 12 week survival rates were 66% (40/61) and 53% (32/60), respectively. Baseline characteristics associated with survival at day 84 were an underlying disease in remission (not relapsing or refractory) and Karnofsky score. Recovery from neutropenia at the end of treatment was also significantly associated with survival. No serious drug-related adverse events or discontinuations due to drug-related adverse events were observed. CONCLUSIONS: Caspofungin provided an observed response rate compatible with the null hypothesis of a true response rate of < or =35%. Underlying disease-related factors had a major impact on results.

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Invasive aspergillosis (IA) is a life-threatening infection due to Aspergillus fumigatus and other Aspergillus spp. Drugs targeting the fungal cell membrane (triazoles, amphotericin B) or cell wall (echinocandins) are currently the sole therapeutic options against IA. Their limited efficacy and the emergence of resistance warrant the identification of new antifungal targets. Histone deacetylases (HDACs) are enzymes responsible of the deacetylation of lysine residues of core histones, thus controlling chromatin remodeling and transcriptional activation. HDACs also control the acetylation and activation status of multiple non-histone proteins, including the heat shock protein 90 (Hsp90), an essential molecular chaperone for fungal virulence and antifungal resistance. This review provides an overview of the different HDACs in Aspergillus spp. as well as their respective contribution to total HDAC activity, fungal growth, stress responses, and virulence. The potential of HDAC inhibitors, currently under development for cancer therapy, as novel alternative antifungal agents against IA is discussed.

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PCR methods are reliable and suitable to in situ identify dermatophytes, yeasts and non dermatophyte moulds (NDM) in onychomycosis. Onychomycosis insensitive to standard treatment with topical agents as well as with oral terbinafine or itraconazole revealed Fusarium spp., Acremonium spp. and Aspergillus spp. as infectious agents. However, NDM onychomycosis could be efficiently cured using topical amphotericin B. In conclusion, correct fungal species identification is important in onychomycoses in order to prescribe adequate treatments since dermatophytes and moulds have different sensitivities to antifungal drugs.

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We evaluated isothermal microcalorimetry for real-time susceptibility testing of non-Aspergillus molds. MIC and minimal effective concentration (MEC) values of Mucorales (n = 4), Fusarium spp. (n = 4), and Scedosporium spp. (n = 4) were determined by microbroth dilution according to the Clinical Laboratory Standard Institute M38-A2 guidelines. Heat production of molds was measured at 37 °C in Sabouraud dextrose broth inoculated with 2.5 × 10(4) spores/mL in the presence of amphotericin B, voriconazole, posaconazole, caspofungin, and anidulafungin. As determined by microcalorimetry, amphotericin B was the most active agent against Mucorales (MHIC 0.06-0.125 μg/mL) and Fusarium spp. (MHIC 1-4 μg/mL), whereas voriconazole was the most active agent against Scedosporium spp. (MHIC 0.25 to 8 μg/mL). The percentage of agreement (within one 2-fold dilution) between the MHIC and MIC (or MEC) was 67%, 92%, 75%, and 83% for amphotericin B, voriconazole, posaconazole, and caspofungin, respectively. Microcalorimetry provides additional information on timing of antifungal activity, enabling further investigation of drug-mold and drug-drug interaction, and optimization of antifungal treatment.

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The use of antimycotic drugs in fungal infections is based on the concept that they suppress fungal growth by a direct killing effect. However, amphotericin and nystatin have been reported to also trigger interleukin-1β (IL-1β) secretion in monocytes but the molecular mechanism is unknown. Here we report that only the polyene macrolides amphotericin B, nystatin, and natamycin but none of the tested azole antimycotic drugs induce significant IL-1β secretion in-vitro in dendritic cells isolated from C57BL/6 mouse bone marrow. IL-1β release depended on Toll-like receptor-mediated induction of pro-IL-1β as well as the NLRP3 inflammasome, its adaptor ASC, and caspase-1 for enzymatic cleavage of pro-IL-1β into its mature form. All three drugs induced potassium efflux from the cells as a known mechanism for NLRP3 activation but the P2X7 receptor was not required for this process. Natamycin-induced IL-1β secretion also involved phagocytosis, as cathepsin activation as described for crystal-induced IL-1β release. Together, the polyene macrolides amphotericin B, nystatin, and natamycin trigger IL-1β secretion by causing potassium efflux from which activates the NLRP3-ASC-caspase-1. We conclude that beyond their effects on fungal growth, these antifungal drugs directly activate the host's innate immunity.

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This report discusses the present status of antifungal therapy and treatment options for candidaemia, considered by experts in the field in Europe. A conference of 26 experts from 13 European countries was held to discuss strategies for the treatment and prevention of invasive candidiasis, with the aim of providing a review on optimal management strategies. Published and unpublished comparative trials on antifungal therapy were analysed and discussed. Commonly asked questions about the management of candidaemia were selected, and possible responses to these questions were discussed. Panellists were then asked to respond to each question by using a touchpad answering system. After the initial conference, the viewpoint document has been reviewed and edited to include new insights and developments since the initial meeting. For many situations, consensus on treatment could not be reached, and the responses indicate that treatment is likely to be modified on a patient-to-patient basis, depending on factors such as degree of illness, prior exposure to azole antifungals, and the presence of potentially antifungal drug-resistant Candida species.

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Voriconazole is increasingly used as a first-line agent for empirical antifungal therapy of prolonged febrile neutropenia in paediatric cancer patients. We describe the case of a 9-year-old patient with stage IV Burkitt lymphoma, who developed pulmonary and splenic zygomycosis while receiving voriconazole for persistent febrile neutropenia. The causative agent, Absidia corymbifera, was identified by broad-range fungal PCR in a lung biopsy sample. The patient was successfully treated with a combination of partial resection of the left upper lobe and antifungal therapy with high-dose liposomal amphotericin B followed by oral itraconazole as demonstrated by resolving pulmonary infiltrates on serial high resolution CT scans. CONCLUSION: This case emphasises that the lack of in vitro activity of voriconazole against zygomycetes is clinically relevant. Failure of voriconazole in suspected fungal infection should be investigated for the possibility of zygomycosis. Broad-range polymerase chain reaction may be able to identify the causative organism when cultures remain sterile.

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Caspofungin at standard dose was evaluated as first-line monotherapy of mycologically documented probable/proven invasive aspergillosis (IA) (unmodified European Organisation for Research and Treatment of Cancer/Mycosis Study Group criteria) in allogeneic hematopoietic SCT patients. The primary efficacy end point was complete or partial response at end of caspofungin treatment. Response at week 12, survival and safety were additional end points. Enrollment was stopped prematurely because of low accrual, with 42 enrolled and 24 eligible, giving the study a power of 85%. Transplant was from unrelated donors in 16 patients; acute or chronic GVHD was present in 15. In all, 12 patients were neutropenic (<500/microl) at baseline, 10 received steroids and 16 calcineurin inhibitors or sirolimus. Median duration of caspofungin treatment was 24 days. At the end of caspofungin therapy, 10 (42%) patients had complete or partial response (95% confidence interval: 22-63%); 1 (4%) and 12 (50%) had stable and progressing disease, respectively; one was not evaluable. At week 12, eight patients (33%) had complete or partial response. Survival rates at week 6 and 12 were 79 and 50%, respectively. No patient had a drug-related serious adverse event or discontinued because of toxicity. Caspofungin first-line therapy was effective and well tolerated in allogeneic hematopoietic SCT patients with mycologically documented IA.

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The identification of clinical risk factors for AIDS in patients with preserved immune function is of significant interest. We examined whether patients with fungal infection (FI) and CD4 cell count >or=200/microl were at higher risk of disease progression in the era of cART. 11,009 EuroSIDA patients were followed from their first CD4 cell count >or=200/microl after 1 January 1997 until progression to any non-azoles/amphotericin B susceptible (AAS) AIDS disease, last visit or death. Initiation of antimycotic therapy (AMT) was used as a marker of FI and was modelled as a time-updated covariate using Poisson regression. After adjustment for current CD4 cell count, HIV-RNA, starting cART and diagnosis of AAS-AIDS, AMT was significantly associated with an increased incidence of non-AAS-AIDS (IRR=1.55, 95% CI 1.17-2.06, p=0.0024). Despite low incidence of AIDS in the cART era, FI in patients with a CD4 cell count >or=200/microl is associated with a 55% higher risk of non-AAS-AIDS (95% confidence interval 1.17-2.06, p=0.0024). These data suggest that patients with FI are more immune compromized than would be expected from their CD4 cell count alone. FI can be used as a clinical marker for disease progression and indirect indicator for initiation/changing cART in settings where laboratory facilities are limited.

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Objectives: Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS-I) suffer from chronic candidosis caused mainly by Candida albicans, and repeated courses of azole antifungals have led to the development of resistance in the APECED patient population in Finland. The aim of our study was to address whether the patients are persistently colonized with the same or genetically closely related strains, whether epidemic strains are present and which molecular mechanisms account for azole resistance. Methods: Sets of C. albicans (n?=?19) isolates from nine APECED patients reported with decreased susceptibility to fluconazole isolated up to 9 years apart were included. The strains were typed by multilocus sequence typing. CDR1/2, MDR1 and ERG11 mRNA expression was analysed by northern blotting and Cdr1, Cdr2 and Mdr1 protein expression by western blotting, and TAC1 and ERG11 genes were sequenced. Results: All seven patients with multiple C. albicans isolates analysed were persistently colonized with the same or a genetically closely related strain for a mean of 5 years. All patients were colonized with different strains and no epidemic strains were found. The major molecular mechanisms behind the azole resistance were mutations in TAC1 contributing to overexpression of CDR1 and CDR2. Six new TAC1 mutations were found, one of which (N740S) is likely to be a gain-of-function mutation. Most isolates were found to have gained multiple TAC1 and ERG11 point mutations. Conclusions: Despite clinically successful treatment leading to relief of symptoms, colonization by C. albicans strains is persistent within APECED patients. Microevolution and point mutations occur within strains, leading to the development of azole-resistant isolates.

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Approximately, twenty years ago, the Rare Cancer Network (RCN) was formed in Lausanne, Switzerland, to support the study of rare malignancies. The RCN has grown over the years and now includes 130 investigators from twenty-four nations on six continents. The network held its first international symposium in Nice, France, on March 21-22, 2014. The proceedings of that meeting are presented in two companion papers. This manuscript reviews the history of the growth of the RCN and contains the abstracts of fourteen oral presentations made at the meeting of prior RCN studies. From 1993 to 2014, 74 RCN studies have been initiated, of which 54 were completed, 10 are in progress or under analysis, and 9 were stopped due to poor accrual. Forty-four peer reviewed publications have been written on behalf of the RCN.

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OBJECTIVES: Invasive mould infections are associated with a high mortality rate and the emergence of MDR moulds is of particular concern. Calcineurin and its chaperone, the heat shock protein 90 (Hsp90), represent an important pathway for fungal virulence that can be targeted at different levels. We investigated the antifungal activity of compounds directly or indirectly targeting the Hsp90-calcineurin axis against different mould species. METHODS: The in vitro antifungal activity of the anticalcineurin drug FK506 (tacrolimus), the Hsp90 inhibitor geldanamycin, the lysine deacetylase inhibitor trichostatin A and the Hsp70 inhibitor pifithrin-μ was assessed by the standard broth dilution method against 62 clinical isolates of Aspergillus spp. and non-Aspergillus moulds (Mucoromycotina, Fusarium spp., Scedosporium spp., Purpureocillium/Paecilomyces spp. and Scopulariopsis spp.) RESULTS: FK506 had variable antifungal activity against different Aspergillus spp. and was particularly active against Mucor spp. Geldanamycin had moderate antifungal activity against Fusarium spp. and Paecilomyces variotii. Importantly, trichostatin A had good activity against the triazole-resistant Aspergillus ustus and the amphotericin B-resistant Aspergillus terreus as well as the MDR Scedosporium prolificans. Moreover, trichostatin A exhibited synergistic interactions with caspofungin against A. ustus and with geldanamycin against Rhizopus spp. for which none of the other agents showed activity. Pifithrin-μ exhibited little antifungal activity. CONCLUSIONS: Targeting the Hsp90-calcineurin axis at different levels resulted in distinct patterns of susceptibility among different fungal species. Lysine deacetylase inhibition may represent a promising novel antifungal strategy against emerging resistant moulds.