Cuantificación de la fibrosis hepática mediante biomarcadores de imagen

NIR-II imaging-guided diagnosis and evaluation of the therapeutic effect on acute alcoholic liver injury via a nanoprobe

Acute alcoholic liver injury (AALI) is hard to diagnose on account of no obvious clinical symptoms, and thereby it easily develops into serious liver diseases and threatens people's health. However, traditional methods for detecting AALI are far from satisfactory due to the low sensitivity, invasiveness and non-visualization, and the development of new techniques is in urgent demand. Near-infrared (NIR)-II fluorescence imaging has been widely studied in biochemistry and biomedicine. As the blood flow velocity of the liver is closely related to the progression of AALI, herein, a NIR-II fluorescent nanoprobe, NTPB-NPs, was applied to diagnose AALI by monitoring the fluorescence intensity changes in the liver caused by the variations of the blood flow velocity. More importantly, when medication was applied to alleviate the liver injury of AALI mice, NTPB-NPs could also track the therapeutic effect in situ. In this study, the relationship between hepatic vascular velocity and the progression of AALI was confirmed with NTPB-NPs via NIR-II imaging. To the best of our knowledge, this is the first time that a NIR-II fluorescence imaging technique has been used to diagnose AALI mice and evaluate the therapeutic effect on AALI mice. This study may also provide a potential NIR-II imaging agent for clinical research to improve the management of liver injury related diseases.

Quantitative evaluation of hepatic fibrosis by fibro Scan and Gd-EOB-DTPA-enhanced T1 mapping magnetic resonance imaging in chronic hepatitis B

PURPOSE

Studies have found that both FibroScan (FS) and Gd-EOB-DTPA-enhanced T1 mapping magnetic resonance imaging (Gd-MRI) could assess liver fibrosis (LF) with high effectiveness. The aim of this study is to compare their accuracy in the quantitative evaluation of LF in patients with chronic hepatitis B (CHB), and to explore the diagnostic accuracy of their combination.

METHODS

160 patients with CHB were included in this study. FS and Gd-MRI were performed within 3 months before the pathological LF staging, which was classified according to the Scheuer-Ludwig scale. The liver stiffness measurement (LSM) was obtained by FS. T1 mapping images of the liver before and 20 min after enhancement were obtained by Look-Locker Gd-MRI.

RESULTS

There were 45, 35, 31 and 49 patients with stage S1, S2, S3 and S4 LF, respectively. LSM increased and the reduction rate of T1 relaxation time of 20 min (rrT1_20min%) decreased with the severity of LF. The area under curve (AUC) of LSM, rrT1_20min% and LSM + rrT1_20min% for the diagnosis of ≥ S2 LF were 0.892, 0.811 and 0.900, respectively. The AUC for ≥ S3 LF was 0.883, 0.838 and 0.899, respectively. The AUC for S4 LF was 0.882, 0.894 and 0.928, respectively.

CONCLUSION

The diagnostic accuracy of FS is better than that of Gd-MRI in the evaluation of ≥ S2 stage LF. The combination of these two methods significantly improved the diagnostic efficiency in the evaluation of S4 stage LF.

Magnetic Resonance imaging analysis of liver fibrosis and inflammation: overwhelming gray zones restrict clinical use

Magnetic resonance (MR) identification and grading of subjects with liver fibrosis and inflammation represents a clinical challenge. MR elastography plays a well-defined role in fibrosis estimation, but its use is not widely available in clinical settings. Given that liver MR is becoming the reference standard for fat and iron quantitation, there is a need to clarify whether there is any role for MR imaging in the concomitant evaluation of fibrosis and inflammation in this setting. This review summarizes the diagnostic estimations of different MR imaging parameters obtained from conventional non-contrast-enhanced multiple b values diffusion-weighted acquisitions, variable flip angles T1 relaxation maps and STIR images. Although some derived parameters have shown a significant correlation to histological scores, a small magnitude of effect with wide overlap across severity grades is the rule. Contrary to fat and iron quantification, the low precision and reproducibility of MR imaging metrics limits its clinical relevance in fibrosis and inflammation assessment. In a sequential clinical approach combining different methodologies, MR imaging has no applicability for ruling-out and low accuracy for ruling-in advanced fibrosis. Thereby, MR elastography remains as the only image method with high diagnostic accuracy for the detection of advanced fibrosis. Until date, inflammation remains in a gray zone where biopsy cannot be replaced, and further investigations are needed. The present review offers an in-depth discuss of the MR imaging diagnostic performance for the evaluation of liver fibrosis and inflammation, highlighting the need for scientific improvements.

Celecoxib attenuates hepatocyte apoptosis by inhibiting endoplasmic reticulum stress in thioacetamide-induced cirrhotic rats

BACKGROUND

Endoplasmic reticulum (ER) stress is an important mechanism in the progression of chronic and acute liver diseases, especially in the progression and recovery of liver fibrosis. Excessive and long-term ER stress induces apoptosis. ER stress-induced apoptosis is considered to be an important pathway in the development of liver fibrosis. Cyclooxygenase-2 (COX-2) induction is also closely related to ER stress. In our previous studies, we showed that celecoxib, a COX-2 inhibitor, improves liver fibrosis and portal hypertension. However, the role and mechanism of celecoxib in alleviating liver fibrosis remain unclear.

AIM

To investigate whether celecoxib alleviates liver fibrosis by inhibiting hepatocyte apoptosis via the ER stress response.

METHODS

Cirrhosis was induced by intraperitoneal injections of thioacetamide (TAA) for 16 wk (injection dose is 200 mg/kg per 3 d for the first 8 wk and 100 mg /kg per 3 d after 8 wk). Thirty-six male Sprague-Dawley rats were randomly divided into three groups, namely, control group, TAA group, and TAA + celecoxib group. In the last 8 wk, TAA-induced cirrhotic rats received celecoxib (20 mg/kg/day) or the vehicle by gastric gavage. After 16 wk, the rats were sacrificed, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB) were detected. The hepatic fibrosis areas were evaluated by Sirius red staining and the degree of fibrosis was assessed by measuring the level of hydroxyproline. ER stress levels were evaluated by detecting the marker proteins glucose-regulated protein 78 (GRP78), CCAAT/enhancer binding protein homologous protein (CHOP), PKR-like ER protein kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 alpha (IRE1α). Apoptosis levels were evaluated by detecting caspase-12 and caspase-3.

RESULTS

The serum ALT and AST levels in the liver were significantly reduced by celecoxib; however, the serum ALB had no significant changes. Celecoxib significantly reduced the degree of liver fibrosis and the levels of hydroxyproline (-38% and -25.7%, respectively, P < 0.01). Celecoxib ameliorated ER stress by reducing the level of GRP78 compared to the TAA group (P < 0.05). Consistently, after celecoxib administration, the upregulation of TAA-induced hepatic apoptosis markers (caspase-12 and caspase-3) and CHOP were significantly inhibited. In addition, after celecoxib treatment, the expression of key molecules associated with ER stress (PERK, ATF6, and IRE1) was decreased (P < 0.05).

CONCLUSION

Therapeutic administration of celecoxib effectively reduces hepatic apoptosis in TAA-induced cirrhotic rats. The mechanism of action may be attributed to the suppression of CHOP expression, which subsequently inhibits ER stress.

Diffusion-weighted magnetic resonance imaging and micro-RNA in the diagnosis of hepatic fibrosis in chronic hepatitis C virus

BACKGROUND

Diffusion-weighted magnetic resonance imaging has shown promise in the detection and quantification of hepatic fibrosis. In addition, the liver has numerous endogenous micro-RNAs (miRs) that play important roles in the regulation of biological processes such as cell proliferation and hepatic fibrosis.

AIM

To assess diffusion-weighted magnetic resonance imaging and miRs in diagnosing and staging hepatic fibrosis in patients with chronic hepatitis C.

METHODS

This prospective study included 208 patients and 82 age- and sex-matched controls who underwent diffusion-weighted magnetic resonance imaging of the abdomen, miR profiling, and liver biopsy. Pathological scoring was classified according to the METAVIR scoring system. The apparent diffusion coefficient (ADC) and miR were calculated and correlated with pathological scoring.

RESULTS

The ADC value decreased significantly with the progression of fibrosis, from controls (F0) to patients with early fibrosis (F1 and F2) to those with late fibrosis (F3 and F4) (median 1.92, 1.53, and 1.25 × 10^-3 mm²/s, respectively) (P = 0.001). The cut-off ADC value used to differentiate patients from controls was 1.83 × 10^-3 mm²/s with an area under the curve (AUC) of 0.992. Combining ADC and miR-200b revealed the highest AUC (0.995) for differentiating patients from controls with an accuracy of 96.9%. The cut-off ADC used to differentiate early fibrosis from late fibrosis was 1.54 × 10^-3 mm²/s with an AUC of 0.866. The combination of ADC and miR-200b revealed the best AUC (0.925) for differentiating early fibrosis from late fibrosis with an accuracy of 80.2%. The ADC correlated with miR-200b (r = - 0.61, P = 0.001), miR-21 (r = - 0.62, P = 0.001), and miR-29 (r = 0.52, P = 0.001).

CONCLUSION

Combining ADC and miRs offers an alternative surrogate non-invasive diagnostic tool for diagnosing and staging hepatic fibrosis in patients with chronic hepatitis C.