YKL-40 and transient elastography, a powerful team to assess hepatic fibrosis.

OBJECTIVE: Transient elastography (TE) is a non-invasive and accurate method for the diagnosis of severe hepatic fibrosis and cirrhosis (F = 3 and F = 4). However, the assessment of significant fibrosis (F = 2) by TE is impaired due to a high variation in the diagnostic accuracy. Within this study, we aim to compare the diagnostic value of TE and experimental biomarkers of liver fibrosis. MATERIAL AND METHODS: A total of 55 patients with chronic liver disease of different etiologies were included in the study. Among them, patients with HCV infection represented the largest cohort (n = 25). Liver fibrosis was evaluated according to the Desmet/Scheuer score. All patients received TE. Serum concentrations of YKL-40, hyaluronic acid (HA), Laminin, C-terminal procollagen I peptide, MMP-9, TIMP-1, TIMP-2 and MMP-9/TIMP-1 complex were determined by ELISA. RESULTS: In the total patient population, areas under the receiver operator characteristic curve (AUROC) for TE were 0.798 (F ≥ 2), 0.880 (F ≥ 3) and 1 (F = 4). Among the serum markers, highest diagnostic accuracies were calculated for YKL-40 for F ≥ 2 (0.792) and F ≥ 3 (0.914) and for YKL-40 and HA for F = 4 (both 0.936). In the subgroup of HCV patients, the following AUROCs for TE were calculated: 0.802 (F ≥ 2), 0.798 (F ≥ 3) and 0.998 (F = 4). YKL-40 exhibited the highest diagnostic accuracy of all biomarkers in the HCV population (0.880, 0.854 and 0.986, respectively). CONCLUSIONS: YKL-40 is a powerful fibrosis marker with high diagnostic accuracy, in particular in HCV-associated liver disease. Its determination may confirm and improve the diagnostic accuracy of TE especially in early stages of liver fibrosis.

Amiloride reduces portal hypertension in rat liver cirrhosis.

OBJECTIVE: This study aimed to investigate the effect of amiloride on portal hypertension. Amiloride is known to inhibit Na(+)/H(+) exchangers on activated hepatic stellate cells. METHODS: Liver cirrhosis in rats was induced by bile duct ligation (BDL) or thioacetamide (TAA) administration. The effects of zymosan for Kupffer cell (KC) activation or a thromboxane (TX) analogue (U46619) were tested in isolated perfused livers of cirrhotic rats and in vivo. Downstream mechanisms were investigated using Rho kinase inhibitor (Y-27632) or amiloride. Acute and chronic effects of amiloride and canrenoate on portal pressure were compared in perfused livers and in vivo. TXB(2) efflux was measured by ELISA. The phosphorylation state of moesin (p-moesin) as an indicator of Rho kinase activity and expression of the thromboxane synthase were assessed by western blot analyses. The activity of hepatic stellate cells was analysed by western blot and staining for alpha-smooth muscle actin (alpha-SMA). RESULTS: In BDL rats, KC activation via zymosan increased portal pressure. This was attenuated by the Rho kinase inhibitor Y-27632. Increased thromboxane efflux following zymosan infusion remained unaltered by Y-27632. The infusion of amiloride attenuated zymosan- and U46619-induced increases in portal perfusion pressure. In vivo, direct administration of amiloride, but not of canrenoate, lowered portal pressure. In TAA and BDL rats, treatment with amiloride for 3 days reduced basal portal pressure and KC-induced increases in portal pressure whereas canrenoate had no effect. In livers of amiloride-treated animals, the phosphorylation state of moesin and the number of alpha-SMA positive cells were reduced. CONCLUSIONS: Amiloride lowers portal pressure in rat liver cirrhosis by inhibition of intrahepatic vasocontraction. Therefore, patients with cirrhosis and portal hypertension may benefit from amiloride therapy.

Of rodents and humans: a light microscopic and ultrastructural study on cardiomyocytes in pulmonary veins.

Cardiomyocytes in pulmonary veins (PVs) have been reported in rodents and humans. In humans they were related to atrial arrhythmias, including atrial fibrillation (AF). To investigate histological similarities and differences in PV cardiomyocyte localization and distribution, we performed comparative light and electron microscopic studies on humans, rats and mice, and generated a transgenic mouse strain. Results on mice (C57BL/6 and BALBc) and rats (Wistar) revealed that cardiomyocytes regularly extend from the hilus along venous vessels into the lung tissue surrounding individual intrapulmonary veins of varying diameters (70-250 microm). The cardiomyocytes showed the ultrastructure of a normal working myocardium with intact intercalated discs and tightly packed contractile filaments. In both lung and hilus cardiomyocytes were localized either close to the basal lamina of the endothelium or separated from it by smooth muscle cells and/or collagen fibres. In humans (autopsies, n=20) extrapericardiac cardiomyocytes were only found in 23 out of 78 veins and showed an incomplete sleeve at the lung hilus. In addition, cardiomyocytes occurred significantly more often in right than in left veins, however, never in intrapulmonary veins. We discuss the hypothesis that the variance in distribution of PV cardiomyocytes in humans and rodents might reflect the difference in pathogenesis and development of AF.

Transcriptome based individualized therapy of refractory pediatric sarcomas: feasibility, tolerability and efficacy.

Survival rates of pediatric sarcoma patients stagnated during the last two decades, especially in adolescents and young adults (AYAs). Targeted therapies offer new options in refractory cases. Gene expression profiling provides a robust method to characterize the transcriptome of each patient's tumor and guide the choice of therapy. Twenty patients with refractory pediatric sarcomas (age 8-35 years) were assessed with array profiling: ten had Ewing sarcoma, five osteosarcoma, and five soft tissue sarcoma. Overexpressed genes and deregulated pathways were identified as actionable targets and an individualized combination of targeted therapies was recommended. Disease status, survival, adverse events (AEs), and quality of life (QOL) were assessed in patients receiving targeted therapy (TT) and compared to patients without targeted therapy (non TT). Actionable targets were identified in all analyzed biopsies. Targeted therapy was administered in nine patients, while eleven received no targeted therapy. No significant difference in risk factors between these two groups was detected. Overall survival (OS) and progression free survival (PFS) were significantly higher in the TT group (OS: P=0.0014, PFS: P=0.0011). Median OS was 8.83 versus 4.93 months and median PFS was 6.17 versus 1.6 months in TT versus non TT group, respectively. QOL did not differ at baseline as well as at four week intervals between the two groups. TT patients had less grade 1 AEs (P=0.009). The frequency of grade 2-4 AEs did not differ. Overall, expression based targeted therapy is a feasible and likely beneficial approach in patients with refractory pediatric sarcomas that warrants further study.

Kupffer cell activation by hydrogen peroxide: a new mechanism of portal pressure increase.

This study aimed to investigate the effects of reactive oxygen species on the hepatic macrophages, the Kupffer cells (KC), and to identify the relevant targets of vasoconstrictors involved in the regulation of intrahepatic microcirculation and therefore portal pressure. The effects of hydrogen peroxide (H2O2), xanthine/xanthine oxidase or a thromboxane (TX) analogue (U46619; 0.1 microM) were tested in sham-operated and fibrotic livers (bile duct ligation over 4 weeks) during isolated rat liver perfusion and in vivo with or without additional KC blockade (gadolinium chloride, 10 mg kg(-1) body weight, 48 and 24 h, i.p.). To investigate downstream mechanisms, a TXA2 antagonist (BM 13.177; 20 microM) or a Rho kinase inhibitor (Y27632; 10 microM) was infused additionally. TXB2 efflux was measured by enzyme-linked immunosorbent assay. The phosphorylation state of moesin (p-moesin), as indicator for Rho kinase activity, was assessed by Western blot analyses. Portal pressure was dose-dependently increased by H2O2 (maximum, 0.5 mM) and, to a lower extent, by xanthine/xanthine oxidase together with catalase. The portal pressure increase by H2O2 was attenuated by previous KC blockade. TXA2 efflux increased after H2O2 infusion and was reduced by KC blockade. The TXA2 antagonist counteracted the H2O2-induced increase in portal pressure. The Rho kinase inhibitor attenuated portal pressure increase after TXA2 analogue or H2O2 infusion. Hepatic levels of p-moesin were increased after H2O2 infusion. Reactive oxygen species increased portal pressure via stimulation of TXA2 production by KCs and a subsequent Rho kinase-dependent contraction of the intrahepatic vasculature. In conclusion, the KCs that are well known to produce H2O2 could also be activated by H2O2. This vicious cycle may best be interrupted at the earliest time point.