Application of CT contrast medium is not associated with an increased risk for acute kidney injury in patients with decompensated cirrhosis.

BACKGROUND: Acute kidney injury (AKI) is a frequent complication in patients with decompensated cirrhosis. Studies reported conflicting results regarding the nephrotoxic potential of iodinated contrast medium (CM) for computer tomography (CT). AIM: To investigate the impact of diagnostic CM application on kidney function in patients with decompensated cirrhosis. METHODS: First, we evaluated the impact of diagnostic CM-CT on AKI incidence in a cross-sectional approach. Second, we analysed 28-day AKI incidence post-CM-CT in patients with impaired kidney function (i.e., creatinine >133 µmoL/L). Third, we excluded all patients with relevant interventions besides CM-CT. All remaining patients were matched via propensity score matching (PPSM) and further analysed. Last, we validated the results in an independent dataset of prospectively collected registry data of 118 patients with decompensated cirrhosis. Here, plasma samples were analysed regarding neutrophil-gelatinase-associated-lipocalin (NGAL). RESULTS: Of the 611 included patients, 98 (16%) received CM-CT. CM-CT was not associated with AKI in the cross-sectional approach (CM-CT:8% vs. no CM-CT:15%; p = 0.08). Furthermore, CM-CT was not associated with higher 28-day AKI incidence among patients with impaired kidney function (HR:0.79; 95% CI 0.45-1.38; p = 0.40). The PPSM cohort revealed no association between CM-CT and AKI or severe AKI (HR:1.28, p = 0.45 and HR:1.62; p = 0.43). Moreover, CM-CT did not result in worsening of kidney function after CM application. In the validation cohort, CM-CT was also not linked to AKI (p = 0.85) and NGAL levels were not increased in those with CM-CT (CM-CT:309 ng/ml vs. No CM-CT:266 ng/ml, p = 0.35). CONCLUSION: Decompensated cirrhosis per se should not preclude diagnostic CM-CT.

Metamizole-Associated Risks in Decompensated Hepatic Cirrhosis.

BACKGROUND: Because of the increased risk of acute renal failure (ARF), the use of cyclooxygenase (COX) inhibitors is not recommended in patients with decompensated hepatic cirrhosis. Metamizole is not a classic COX inhibitor, but there are insufficient data to support its safe use. In this study, we investigate the effect of metamizole on the risk of ARF in these patients. METHODS: Metamizole use, ARF incidence, and patient mortality were examined in a large, retrospective, exploratory cohort and validated with data from a prospective registry. RESULTS: 523 patients were evaluated in the exploratory cohort. Metamizole use at baseline was documented in 110 cases (21%) and was independently associated with the development of ARF, severe (grade 3) ARF, and lower survival without liver transplantation at follow-up on day 28 (HR: 2.2, p < 0.001; HR: 2.8, p < 0.001; and HR: 2.6, p < 0.001, respectively). Interestingly, the risk of ARF depended on the dose of metamizole administered (HR: 1.038, p < 0.001). Compared to patients who were treated with opioids, the rate of ARF was higher in the metamizole group (49% vs. 79%, p = 0.014). An increased risk of ARF with metamizole use was also demonstrated in the independent validation cohort (p < 0.001). CONCLUSION: Metamizole therapy, especially at high doses, should only be used with a high level of caution in patients with decompensated cirrhosis.

Interdependent Impact of Lipoprotein Receptors and Lipid-Lowering Drugs on HCV Infectivity.

The HCV replication cycle is tightly associated with host lipid metabolism: Lipoprotein receptors SR-B1 and LDLr promote entry of HCV, replication is associated with the formation of lipid-rich membranous organelles and infectious particle assembly highjacks the very­low-density lipoprotein (VLDL) secretory pathway. Hence, medications that interfere with the lipid metabolism of the cell, such as statins, may affect HCV infection. Here, we study the interplay between lipoprotein receptors, lipid homeostasis, and HCV infection by genetic and pharmacological interventions. We found that individual ablation of the lipoprotein receptors SR­B1 and LDLr did not drastically affect HCV entry, replication, or infection, but double lipoprotein receptor knock-outs significantly reduced HCV infection. Furthermore, we could show that this effect was neither due to altered expression of additional HCV entry factors nor caused by changes in cellular cholesterol content. Strikingly, whereas lipid­lowering drugs such as simvastatin or fenofibrate did not affect HCV entry or infection of immortalized hepatoma cells expressing SR-B1 and/or LDLr or primary human hepatocytes, ablation of these receptors rendered cells more susceptible to these drugs. Finally, we observed no significant differences between statin users and control groups with regards to HCV viral load in a cohort of HCV infected patients before and during HCV antiviral treatment. Interestingly, statin treatment, which blocks the mevalonate pathway leading to decreased cholesterol levels, was associated with mild but appreciable lower levels of liver damage markers before HCV therapy. Overall, our findings confirm the role of lipid homeostasis in HCV infection and highlight the importance of the mevalonate pathway in the HCV replication cycle.

Frequency of Potential Drug-Drug Interactions in the Changing Field of HCV Therapy.

BACKGROUND: With the introduction of direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection, drug-drug interactions (DDIs) emerged as significant challenge. Since then, HCV therapy and the infected population have rapidly changed. So far, very limited data are available regarding the clinical relevance of DDIs when using most modern DAA regimens. We aimed to assess how the importance of DDIs has evolved over time. METHODS: From January 2014 to July 2018, 668 consecutive HCV patients were evaluated for their outpatient medication and assessed for DDIs with DAAs. Different time periods were defined based on market approval of key DAAs: A (01/2014-11/2014), B (11/2014-08/2016), and C (08/2016-07/2018). RESULTS: The frequency of patients with real-world DDIs was highest in period B (A: 37.1%, B: 49.6%, C: 38.8%). The recently approved DAAs (period C) theoretically showed a lower DDI risk profile. However, real-world DDIs were still comparable to period A, as HCV patients' characteristics changed (eg, age ≥75 years: A: 3.1%, B: 9.8%, C: 5.6%; polypharmacy/patients with ≥8 drugs: A: 11.1%, B: 15.2%, C: 17.2%). Furthermore, although DDIs via CYP 3A4 became less important for some modern regimens, other mechanisms like an altered pH value in the stomach, causing reduced bioavailability, evolved. Relevant DDIs most frequently occurred with proton pump inhibitors, metamizole, statins, and carvedilol. CONCLUSIONS: DDIs during antiviral treatment still affect about 40% of HCV patients. The lower DDI potential of modern DAA regimens is partly counteracted by changing patient characteristics. Therefore, DDIs should not be underestimated.

Treatment of Chronic Hepatitis C: Efficacy, Side Effects and Complications.

BACKGROUND: Chronic hepatitis C virus (HCV) infection can lead to liver cirrhosis and its complications. Viral eradication is essential to prevent disease progression and reduces liver-related mortality and morbidity. Since the availability of direct-acting antivirals (DAA), HCV treatment has changed significantly. Current treatment strategies for different groups of patients as well as potential risks and caveats will be discussed in this review. SUMMARY: Interferon-free (IFN-free) treatment not only shortens treatment duration, but also achieves high rates of viral clearance and is overall well tolerated. Genotype-restricted but also pangenotypic combinations are available. Usually two DAA of different drug classes are combined. For the majority of the patients, treatment duration ranges from 8 to 12 weeks. Liver and kidney function as well as prior treatment experience and potential drug-drug interactions influence substance choices and treatment duration. However, modern IFN-free treatment is not only safer, but also overall far more simplified and effective. Global HCV eradication might be an ambitious but not completely unrealistic goal to pursue. KEY MESSAGES: IFN-free antiviral treatment is safe and well tolerated. Patients can be treated almost independently of liver function or concomitant disease. Viral eradication is associated with reduced morbidity and mortality and better quality of life.

Fecal calprotectin is a useful screening parameter for hepatic encephalopathy and spontaneous bacterial peritonitis in cirrhosis.

OBJECTIVE: Bacterial translocation, causing intestinal inflammation, is one of the key mechanisms in the pathogenesis of hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP) The presence of fecal calprotectin quantitatively relates to intestinal neutrophil migration and is therefore considered as a marker of intestinal inflammation. We aimed to assess the role of fecal calprotectin concentrations (FCCs) in diagnosing the onset and severity of HE and SBP. METHODS: Sixty-one cirrhotics were prospectively included. Forty-two subjects served as controls. Several complications of cirrhosis were diagnosed by reference methods. Stool samples were collected for measuring FCCs. Patients revealing other causes of abnormal calprotectin results, e.g. gastrointestinal bleeding or inflammatory bowel disease were excluded. Multivariate analysis of cirrhosis-associated complications and their relation to FCCs was performed. RESULTS: Fecal calprotectin concentrations were higher in cirrhotics compared with controls (P<0.001). Among cirrhotics, FCCs were elevated dependent on the severity of liver disease as assessed by Child- and model for end-stage liver disease-scores. The corresponding correlation co-efficients by Spearman's were 0.577 (P<0.001) and 0.303 (P=0.018) respectively. A correlation emerged between elevated FCCs and HE grading as measured by West-Haven criteria and critical flicker frequency (both P<0.001; sensitivity=0.94 and 0.93, specificity=0.95 and 0.89 respectively) and SBP (P<0.02; sensitivity=0.71, specificity=0.79). FCCs were higher in cirrhotic subjects with additional extra-intestinal inflammation (P<0.01; sensitivity=0.65, specificity=0.8). The Pearsons correlation coefficients were 0.190 and 0.164 revealing no influence (P=0.142 and P=0.207) of laboratory parameters of systemic inflammation on FCCs in cirrhotic subgroup. CONCLUSIONS: Fecal calprotectin concentrations serve as a screening tool for HE and SBP. Assessment of FCCs may faciliate grading of HE-severity.