Histopathologische Diagnose der nichtalkoholischen und alkoholischen Fettlebererkrankung: Konsensusbasierte Leitlinie der Stufe 2

Diagnostic Value of Ultrasound in Fatty Liver Disease

Hepatic steatosis is a commonly seen phenomenon in clinical practice and is the result of the accumulation of lipids in the hepatocytes. In most cases steatosis refers to nonalcoholic fatty liver disease (NAFLD), but it also occurs in other diseases of the liver parenchyma of a different etiology and is the result of the dysregulation of metabolic processes. Consequently, inflammatory processes can induce progressive fibrosis. Due to the high prevalence of fatty liver disease, a further increase in metabolic liver cirrhosis with corresponding complications can be expected in the near future. Due to its broad availability, ultrasound is particularly important, especially for the management of NAFLD. In addition to diagnosis and risk stratification, the monitoring of high-risk patients in NAFLD is becoming increasingly clinically important. Multimodality ultrasound includes B-mode and duplex methods, analysis of tissue stiffness (elastography), contrast-enhanced imaging (CEUS), and steatosis quantification. When using ultrasound in fatty liver disease, a standardized approach that takes into account the limitations of the method is essential.

[Histopathological diagnosis and differential diagnosis of nonalcoholic fatty liver disease]

Fatty liver disease is a rising problem worldwide, particularly due to metabolic syndrome. The current prevalence is 20-30%, but a further increase is expected whereby children will also be increasingly affected. The presence of fat in hepatocytes is known as steatosis or, in the case of nonalcoholic origin, nonalcoholic fatty liver (NAFL). It is basically reversible, but can progress to steatohepatitis (NASH) as an active and progressive form of fatty liver disease due to continuous cell damage. This leads to progressive liver fibrosis up to end-stage liver cirrhosis. The gold standard of diagnosis is liver biopsy, in which obesity, inflammation, and hepatocellular damage (hepatocellular ballooning) are assessed for the distinction between NAFL and NASH. The extent of fibrosis indicates the progress of the disease. Childhood and adult fatty liver diseases differ morphologically, particularly in the location and amount of fat, inflammation, and fibrosis. Alcoholic and nonalcoholic fatty liver disease/steatohepatitis cannot be reliably differentiated by histology. Clinical parameters must also be taken into consideration for the differential diagnosis of other diseases associated with fatty liver. The main therapeutic goal is to reduce insulin resistance, which can be achieved through weight loss and lifestyle changes. Recently, however, drug therapies have also become available as a promising therapeutic option.

Effect of weight loss induced by laparoscopic sleeve gastrectomy on liver histology and serum adipokine levels

BACKGROUND & AIM

Bariatric surgery is a valid treatment option for persons with non-alcoholic fatty liver disease. This study prospectively examined the impact of laparoscopic sleeve gastrectomy (LSG) on liver histopathology, and blood levels of adiponectin, leptin, resistin, and pre-B cell enhancing factor/Nampt/visfatin.

PATIENTS & METHODS

In 81 patients with non-alcoholic fatty liver disease who underwent LSG, paired liver biopsies and blood specimens were obtained before and 18 months after LSG. Differences between preoperative and 18 months postoperative data were tested by paired Student's t-test or Wilcoxon rank test as appropriate.

RESULTS

At follow up, there was a significant improvement in biochemical markers for glucose homeostasis, including fasting glucose, HbA1c, insulin levels, and homeostatic model assessment index. Postoperative liver function tests, namely serum alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transpeptidase level, showed a significant improvement compared to before weight loss. The number of patients who had definite, borderline, or no non-alcoholic steatohepatitis was 43 (53%), 27 (33%), and 11 (14%), respectively, at baseline, and 9 (11%), 32 (40%), and 40 (49%) at 18-month post-surgery follow up. A significant reduction in steatosis, liver fibrosis, lobular inflammation, and hepatocyte ballooning was observed in the postoperative biopsies (P < 0.001 each). In addition, at the follow-up assessment, there was a significant increase in serum adiponectin levels and significant decline in serum levels of leptin, resisitin, and pre-B cell enhancing factor/Nampt/visfatin.

CONCLUSION

Weight loss after sleeve gastrectomy was associated with a significant improvement in several metabolic parameters, liver enzyme levels, liver histopathology, and changes in serum adipokine levels towards antidiabetic and anti-inflammatory profiles.

Laparoscopic Sleeve Gastrectomy on the Horizon as a Promising Treatment Modality for NAFLD

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is viewed as the hepatic manifestation of the metabolic syndrome with hepatic fatty infiltration is the common liver pathology. NAFLD can lead to nonalcoholic steatohepatitis (NASH), liver cirrhosis, liver cell failure, and liver malignancy.The present work aims to prospectively study the histological changes that occur in NAFLD obese patients 1-year post-laparoscopic sleeve gastrectomy (LSG) based on standardized NAS (NAFLD activity score).

PATIENTS

This prospective study included 94 obese patients who underwent laparoscopic sleeve gastrectomy. Intraoperative wedge liver biopsy was taken from all patients with a follow-up liver biopsy at 12 months after the operation.

RESULTS

LSG produced a marked reduction in body weight with a mean reduction in BMI from 44.54 + 5.45 to 34.23 + 2.66 kg/m² at 12 months. There were statistically highly significant improvements regarding metabolic comorbidities, blood pressure, lipid profile, and HbA1C at 12-month post-LSG (P < 0.001). The current study showed a highly statistically significant improvement at 1-year post LSG regarding steatosis grade, hepatocyte ballooning, lobular inflammation as well as fibrosis stage (P < 0.001). Moreover, the present study showed that NAS score significantly decreased from 5.20 + 1.96 at baseline to 2.63 + 1.55 at 1-year follow-up (P < 0.001).

CONCLUSION

Our relatively large patient cohort shows a significant improvement of steatosis, steatohepatitis, and fibrosis at a 1-year follow-up. LSG can lead to resolution of NAFLD, and it may be in the near future another routine indication for bariatric surgery.

Ultrasound-Based Attenuation Imaging for the Non-Invasive Quantification of Liver Fat - A Pilot Study on Feasibility and Inter-Observer Variability

Attenuation imaging is a novel, ultrasound-based technique to objectively detect and quantify liver steatosis. In this study, we evaluated the performance and inter-observer variability of attenuation imaging and compared it to a known quantification method of liver fat, the hepatorenal index (HRI). Two observers measured attenuation coefficients (AC) in an attenuation phantom, 20 healthy volunteers and 27 patients scheduled for biopsy for suspected diffuse liver disease. Results were compared with the HRI and histological findings. Both observers were blinded to the results of the biopsy and the measurements of the other observer. Our results showed that patients with moderate (S2, 33-66%) and severe fatty infiltration of the liver (S3, >66%) showed significantly higher ACs in comparison to patients with a liver fat fraction of less than 33% (S0/1). There was no significant difference in AC-values of patients with fatty infiltration of less than 5% (S0) and 5-32% (S1). In the Receiver Operating Characteristic (ROC)-analysis, the area under the curve (AUC)-values for the detection of moderate and severe steatosis were excellent at 0.98. Cut-off values were 0.64 dB/cm/MHz for the detection of S2- and 0.68 dB/cm/MHz for the detection of S3-steatosis. The inter-observer agreement of attenuation imaging was very good with an intraclass correlation coefficient (ICC) of 0.92 in patient and 0.96 in phantom measurements. The ICC decreased with depth in the phantom measurements. In summary, attenuation imaging showed very good inter-observer agreement and is a promising tool for the detection and quantification of moderate and severe hepatic steatosis.

Histologic improvement of NAFLD in patients with obesity after bariatric surgery based on standardized NAS (NAFLD activity score)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Nonalcoholic steatohepatitis is the fastest growing cause for liver failure. Bariatric surgery represents a treatment option for NAFLD with an established effect on liver histology.

OBJECTIVES

We aimed to assess the impact of bariatric surgery on standardized liver histology using the NAFLD activity score.

SETTING

Retrospective comparison of metabolic data before and after bariatric surgery and comparison of sleeve gastrectomy and Roux-en-Y gastric bypass. The study was performed in an academic center, the university hospital Schleswig-Holstein in Kiel, Germany.

METHODS

Between 2009 and 2012, bariatric surgery was performed in 257 patients according to the national guidelines, and a liver biopsy was obtained in 150 of these patients during surgery. A follow-up biopsy was available in 53 of these patients at a median of 192 days. Liver histology was analyzed using the NAFLD activity score. In this subgroup of 53 patients an analysis of the metabolic improvement after bariatric surgery and a comparative analysis between the 2 different operative procedures was performed.

RESULTS

The study cohort showed improvement of preoperative pathologic liver histology findings after operative procedures took place. Both surgery methods improved the NAFLD activity score significantly, all improvement -2.0 (confidence interval -2.5 to -1.0; P < .001); Roux-en-Y gastric bypass, improvement -1.0 (confidence interval -2.0 to -.0; P = .038); sleeve gastrectomy, improvement -2.5 (confidence interval -3.5 to -1.5; P < .001). No differences were found with regard to histologic recovery between gastric bypass and sleeve gastrectomy (P = .22).

CONCLUSIONS

Bariatric surgery significantly improves NAFLD.

Age- and Gender Dependent Liver Fat Content in a Healthy Normal BMI Population as Quantified by Fat-Water Separating DIXON MR Imaging

OBJECTIVES

To establish age- and sex-dependent values of magnetic resonance (MR) liver fat-signal fraction (FSF) in healthy volunteers with normal body-mass index (BMI).

METHODS

2-point mDIXON sequences (repetition time/echo time, 4.2msec/1.2msec, 3.1msec) at 3.0 Tesla MR were acquired in 80 healthy volunteers with normal BMI (18.2 to 25.7 kg/m2) between 20 and 62 years (10 men/10 women per decade). FSF was measured in 5 liver segments (segment II, III, VI, VII, VIII) based on mean signal intensities in regions of interest placed on mDIXON-based water and fat images. Multivariate general linear models were used to test for significant differences between BMI-corrected FSF among age subgroups. Pearson and Spearman correlations between FSF and several body measures were calculated.

RESULTS

Mean FSF (%) ± standard deviations significantly differed between women (3.91 ± 1.10) and men (4.69 ± 1.38) and varied with age for women/men (p-value: 0.002/0.027): 3.05 ± 0.49/3.74 ± 0.60 (age group 20-29), 3.75 ± 0.66/4.99 ± 1.30 (30-39), 4.76 ± 1.16/5.25 ± 1.97 (40-49) and 4.09 ± 1.26/4.79 ± 0.93 (50-62). FSF differences among age subgroups were significant for women only (p = 0.003).

CONCLUSIONS

MR-based liver fat content is higher in men and peaks in the fifth decade for both genders.

[Update of the S3 guidelines for pancreatic cancer. What is new for pathologists?]

The S3 guidelines for pancreatic cancer were revised in 2013. Besides the oncological and palliative therapy modalities and surgical therapy, the guidelines for pathologists in topic 3 were updated. The modifications essentially concern the histopathological assessment of surgical specimens and in particular the circumferential resection margin and the R classification. In addition, the current recommendations were amended by recommendations concerning the pathohistological records, which should include the lymph node ratio in the future.

Effects of the compounds resveratrol, rutin, quercetin, and quercetin nanoemulsion on oxaliplatin-induced hepatotoxicity and neurotoxicity in mice

Oxaliplatin (OXA) is a platinum compound widely used in the treatment of some solid tumors, especially colorectal cancer. Despite its usefulness, oxaliplatin-associated neurotoxicity represents the main dose-limiting factor of this drug, and until now, there is no suitable treatment. Chemotherapy with oxaliplatin also increases the rate of developing hepatic damages with inflammatory activity, termed chemotherapy-associated steatohepatitis (CASH). In the present study, we aimed to compare the effects of a series of antioxidant compounds on simultaneous development of oxaliplatin-induced hepato- and neurotoxicity in mice. Mice BALB/c were treated with oxaliplatin for 6 weeks, 10 mg/kg, intraperitoneally, resulting in mechanical allodynia and hepatic steatosis. We administered the following antioxidant compounds--rutin (RT) (20 mg/kg), resveratrol (RVS) (100 mg/kg), quercetin (QT) (20 mg/kg), and quercetin nanoemulsion (NQT) (20 mg/kg)--daily by gavage to BALB/c, and N-acetylcysteine (NAC) was used as positive control. Treatments with RSV, RUT, or NQT were able to prevent mechanical allodynia when compared to the OXA group, and this effect was associated with decreased c-Fos immunopositivity in the lumbar spinal cord. Regarding the effects on steatohepatitis, RVS, QT, and NQT almost completely reversed the mean liver weight increase induced by OXA. In accordance with these previous data, histological evaluation indicated attenuation of all features of hepatic steatosis evaluated in RSV, RUT, QT, and NQT groups. These compounds were able to reduce the immunopositivity for the apoptosis marker caspase-3. On the other hand, only QT and NQT treatments were able to reduce neutrophil migration measured by myeloperoxidase (MPO) activity. These results suggest that the compounds tested, RSV, RUT, QT, and NQT, would be useful for the clinical treatment of neuro- and hepatoxicity induced by oxaliplatin.

[Chronic liver diseases--new therapy. Are biopsies necessary?]

Chronic liver disease can often reliably be assessed only by examination of biopsy material. In this article the possible indications for liver biopsy in viral hepatitis B and C, autoimmune liver disease, steatohepatitis and hereditary metabolic diseases are described. A biopsy may be useful in cases with unclear clinical or serological situations or with questionable chronicity and comorbidities. The assessment of biopsy material should be based on guideline-based classification systems. The value of biopsy diagnosis benefits from a close interdisciplinary clinical pathological cooperation.

Establishment of a standardized liver fibrosis model with different pathological stages in rats

Objective. To establish a standardized animal model for liver fibrosis with the same assessment criteria for liver fibrosis studies that have been established on a unified platform. Methods. The standardized liver fibrosis model was established using Sprague-Dawley (SD) rats that either received an intraperitoneal injection of carbon tetrachloride (CCl(4)) in small dosages or ingested an ethanol solution. Results. The definite corresponding rules among modeling of different weeks and corresponding serology indices as well as different pathological staging can be observed by modeling with small dosages and slow, individualized, and combined administrations. Conclusion. This method can be used for the standardized establishment of a liver fibrosis model in rats across 5 pathological stages, ranging from S0 to S4, with a high success rate (89.33%) and low death rate (17.3%) because of the application of multiple hypotoxic chemicals for modeling. We refer to the criteria of Histological Grading and Staging of Chronic Hepatitis for Fibrosis established by the 10th World Digestive Disease Academic Conference in Los Angeles in September 1994 (revised in November 2000).