Alessia Carnelutti

Oxidative Stress Is Activated by Free Fatty Acids in Cultured Human Hepatocytes

BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is strongly associated to oxidative stress, metabolic syndrome, and cardiovascular risk. Hepatocytes overloaded with fatty acids (FA) could generate substances that interfere with endothelial function, providing a potential explanation for this association. We have investigated the response of cultured human hepatoblastoma cells (Hep-G2) that were exposed to FA by measuring markers of oxidative stress and thrombosis and expression of the insulin receptor. METHODS Hep-G2 cells were conditioned with a mixture of FA with or without N-acetyl-L-cysteine (NAC), glutathione (GSH), or adiponectin (ADN). After 7 days, we measured intracellular GSH (iGSH), nitric oxide (NO), malondialdehyde (MDA), and tissue plasminogen inhibitor-1 (PAI-1). Real-time polymerase chain reaction (PCR) was used to determine gene expression of inducible nitric oxide synthase (iNOS) and insulin receptor (INS-R). RESULTS Exposure to FA decreased iGSH and NO levels in Hep-G2 cells and increased MDA and PAI-1 production. Gene expression of iNOS and INS-R in Hep-G2 cells was decreased by exposure to FA. Co-incubation with NAC and GSH prevented the change of iNOS mRNA levels, but not of INS-R; co-incubation with ADN restored the gene expression of INS-R, but not of i-NOS. ADN prevented also the FA-induced increase in MDA in cultured human endothelial cells. CONCLUSION Exposure to FA activates oxidative stress and production of prothrombotic markers and decreases expression of insulin receptors in cultured human hepatocytes. These effects of FA are partially prevented by ADN and might contribute to the increased cardiovascular risk in patients with NAFLD and metabolic syndrome.

PNPLA3 I148M Polymorphism, Clinical Presentation, and Survival in Patients with Hepatocellular Carcinoma

Background & Aims Aim of this study was to evaluate whether the PNPLA3 I148M polymorphism, previously associated with hepatocellular carcinoma (HCC) risk, influences the clinical presentation of HCC and survival. Methods we considered 460 consecutive HCC patients referred to tertiary care centers in Northern Italy, 353 with follow-up data. Results Homozygosity for PNPLA3 148M at risk allele was enriched in HCC patients with alcoholic liver disease or nonalcoholic fatty liver disease (ALD&NAFLD: relative risk 5.9, 95% c.i. 3.5–9.9; other liver diseases: relative risk 1.9, 95% c.i. 1.1–3.4). In ALD&NAFLD patients, the PNPLA3 148M allele was associated with younger age, shorter history of cirrhosis, less advanced (Child A) cirrhosis at HCC diagnosis, and lower HCC differentiation grade (p<0.05). Homozygosity for PNPLA3 148M was associated with reduced survival in the overall series (p = 0.009), and with a higher number of HCC lesions at presentation (p = 0.007) and reduced survival in ALD&NAFLD patients (p = 0.003; median survival 30, 95% c.i. 20–39 vs. 45, 95% c.i. 38–52 months), but not in those with HCC related to other etiologies (p = 0.86; 48, 95% c.i. 32–64 vs. 55, 95% c.i. 43–67 months). At multivariate Cox regression analysis, homozygosity for PNPLA3 148M was the only negative predictor of survival in ALD&NAFLD patients (HR of death 1.57, 95% c.i. 1.12–2.78). Conclusions PNPLA3 148M is over-represented in ALD&NAFLD HCC patients, and is associated with occurrence at a less advanced stage of liver disease in ALD&NAFLD. In ALD&NAFLD, PNPLA3 148M is associated with more diffuse HCC at presentation, and with reduced survival.

Impact of new treatment options for hepatitis C virus infection in liver transplantation

Liver transplant candidates and recipients with hepatitis C virus (HCV)-related liver disease greatly benefit from an effective antiviral therapy. The achievement of a sustained virological response before transplantation can prevent the recurrence of post-transplant HCV disease that occurs universally and correlates with enhanced progression to graft cirrhosis. Previous standard-of-care regimens (e.g., pegylated-interferon plus ribavirin with or without first generation protease inhibitors, boceprevir and telaprevir) displayed suboptimal results and poor tolerance in liver transplant recipients. A new class of potent direct-acting antiviral agents (DAA) characterized by all-oral regimens with minimal side effects has been approved and included in the recent guidelines for the treatment of liver transplant recipients with recurrent HCV disease. Association of sofosbuvir with ribavirin and/or ledipasvir is recommended in liver transplant recipients and patients with decompensated cirrhosis. Other regimens include simeprevir, daclatasvir, and combination of other DAA. Possible interactions should be monitored, especially in coinfected human immunodeficiency virus/HCV patients receiving antiretrovirals.

New therapeutic options for skin and soft tissue infections

Purpose of review The occurrence of methicillin-resistance in Staphylococcus aureus, that represents the most frequent cause of complicated skin and soft tissue infections (cSSTIs) worldwide, is a major concern and has been associated with increased length of stay, health care costs, and overall mortality. Although vancomycin is still considered the standard therapy in this setting, limitations of its use in clinical practice are represented by a progressive increase in methicillin-resistant S. aureus (MRSA) minimum inhibitory concentrations, drug-related toxicity, and the lack of an oral formulation. New therapeutic options for MRSA cSSTIs have recently become available, with promising implications for the management of cSSTIs in clinical practice. Recent findings A number of new antimicrobials with activity against MRSA have been recently approved for the treatment of cSSTIs, and other agents are under investigation. We have reviewed the recent developments, with a specific focus on the possible advantages of new drugs for the management of cSSTIs into the everyday clinical practice. Summary The new approved drugs for the treatment of cSSTIs are expected to offer many advantages for the management of patients with suspected or confirmed MRSA cSSTIs. The most promising features of the new compounds include the availability of oral formulations, once-weekly intravenous regimens, and broad spectra of activity.

Invasive Candida Infections in Liver Transplant Recipients: Clinical Features and Risk Factors for Mortality

Background Invasive fungal infections remain a leading cause of morbidity and mortality among liver transplant recipients (LTRs). In this patient population, invasive Candida infections (ICIs) account for the large majority of cases. To date, only small studies and case-series analysing clinical presentation and risk factors for mortality in LTRs with ICIs are available. Methods We performed a retrospective multicenter multinational study in 10 centers in Europe and Brazil. All consecutive LTRs developing ICIs during the period January 2011 to December 2013 were included in the study. Results A total of 42 LTRs were included. Median age was 52.5 years, and 78.6% of patients were men. Viral hepatitis was the most common cause for liver transplantation (42.9%). Candidemia represented the majority of cases (24, 57.1%), followed by intra-abdominal candidiasis (18, 42.9%). Overall 30-day mortality was 23.8%, with higher mortality in patients with candidemia compared with intra-abdominal candidiasis (37.5% vs 5.6%, P = 0.02). Multivariate analysis showed candidemia to be a risk factor associated with mortality among LTRs presenting ICIs (odds ratio, 11.86; 95% confidence interval, 1.5-280; P = 0.01). Candida albicans represented the most common isolate (59.5%). High rates of antifungal resistances were found, with 16.7% and 4.8% of isolates displaying resistance to azoles and caspofungin, respectively. Conclusions Our study confirms the occurrence of high mortality rates in LTRs developing ICIs. Mortality rates varied according to the type of infection, with candidemia representing a risk factor for mortality. The high rates of antifungal resistance should be considered in the choice of the empiric antifungal regimen.

Patient specific risk stratification for antimicrobial resistance and possible treatment strategies in gram-negative bacterial infections

ABSTRACT Introduction: The isolation of multi-drug-resistant gram-negative (MDRGN) pathogens has progressively increased worldwide and has been associated with important delays in the prescription of an adequate antibiotic treatment, resulting in increased mortality rates. Patient’s stratification for MDRGN infections to optimize the prescription of an adequate empiric antimicrobial regimen is crucial. Areas covered: This article covers MDRGN epidemiology, with a specific focus on risk factors for harbouring infections sustained by extended-spectrum-Beta-lactamase (ESBL), carbapenem resistant Enterobacteriacae (CRE), MDR Pseudomonas aeruginosa and MDR Acinetobacter baumanii. Moreover, we will propose an algorithm for the choice of empiric treatment when a MDRGN infection is suspected. Expert commentary: Although in clinical practice, a patient’s stratification represents a challenge, whenever a MDRGN pathogen is suspected broad-spectrum, combination empiric treatment should be promptly started, looking for a balance between the prescription of an adequate empiric treatment and the risk of resistance selection.

Bloodstream infections in the Intensive Care Unit

ABSTRACT Bloodstream infections (BSIs) represent a common complication among critically ill patients and a leading cause of morbidity and mortality. The prompt initiation of an effective antibiotic therapy is necessary in order to reduce mortality and to improve clinical outcomes. However, the choice of the empiric antibiotic regimen is often challenging, due to the worldwide spread of multi-drug resistant (MDR) organisms with reduced susceptibility to the available broad-spectrum antimicrobials. New therapeutic strategies are 5 to improve the effectiveness of antibiotic treatment while minimizing the risk of resistance selection.

The role of methicillin-resistant Staphylococcus aureus in skin and soft tissue infections

Purpose of review Methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health issue worldwide over the last years. MRSA is frequently implicated in the development of skin and soft tissue infections, leading to significant increases in morbidity, mortality and overall healthcare costs. Recent findings In order to face the threat of MRSA, major changes in clinical management of skin and soft tissue infections are required. The identification of populations at risk for the acquisition of infections due to MRSA, together with the improvement of the diagnostic techniques, is paramount. Moreover, a number of new antimicrobials with activity against MRSA have been recently developed and approved for the treatment of skin and soft tissue infections, however, the use of the new drugs in the wide clinical practice remains limited. Summary We reviewed the current epidemiology of MRSA in skin and soft tissue infections, with particular focus on implications for clinical management. The potential role of new antibiotic options against MRSA infections is also discussed.

New therapeutic options for respiratory tract infections.

Purpose of review The progressive increase of respiratory tract infections caused by multidrug-resistant organisms (MDROs) has been associated with delays in the prescription of an adequate antibiotic treatment and increased mortality, representing a major concern in both community and hospital settings. When infections because of methicillin-resistant Staphylococcus aureus (MRSA) are suspected, vancomycin still represents the first choice, although its efficacy has been recently questioned in favor of new drugs, reported to provide better clinical outcomes. Moreover, few therapeutic options are currently available for the treatment of severe infections caused by Multidrug-resistant (MDR) Gram-negative pathogens, which are frequently resistant to all the available &bgr;-lactams, including carbapenems. We have reviewed the therapeutic options for the treatment of respiratory tract infections that have recently become available with promising implications for clinical practice, including ceftaroline, ceftrobiprole, tedizolid, telavancin, delafloxacin, eravacycline, and new &bgr;-lactams/&bgr;-lactamase inhibitors. Recent findings A number of new antimicrobials with activity against MDROs have been recently approved for the treatment of respiratory tract infections, and other agents are under investigation. Recent developments, with a specific focus on the possible advantages of new drugs for the management of respiratory tract infections caused by MDROs in everyday clinical practice are discussed. Summary Newly approved and investigational drugs for the treatment of respiratory tract infections are expected to offer many advantages for the management of patients with suspected or confirmed infections caused by MDROs. Most promising features among new compounds include the broad spectrum of activity against both MRSA and MDR Gram-negative bacteria, a limited risk of antimicrobial resistance, the availability of oral formulations, and a promising safety profile.

Intra-abdominal penetration and pharmacodynamic exposure to fluconazole in three liver transplant patients with deep-seated candidiasis

Institute of Clinical Pharmacology, Azienda OspedalieroUniversitaria Santa Maria della Misericordia, Udine, Italy; Department of Experimental and Clinical Medical Sciences, University of Udine, Udine, Italy; Clinic of Infectious Diseases, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia, Udine, Italy; Clinic of Internal Medicine-Liver Unit, Department of Experimental and Clinical Medical Sciences, University of Udine, Udine, Italy; Department of Medical and Biological Sciences, University of Udine, Udine, Italy