CD14 upregulation as a distinct feature of non-alcoholic fatty liver disease after pancreatoduodenectomy

Are transmembrane 6 superfamily member 2 gene polymorphisms associated with steatohepatitis after pancreaticoduodenectomy?

Aim

After pancreaticoduodenectomy, 20-40% of patients develop steatotic liver disease (SLD), and steatohepatitis can be a problem. Although patatin-like phospholipase domain-containing 3 protein (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) polymorphisms are involved in SLD and steatohepatitis development, whether this is the case after pancreaticoduodenectomy is unclear.

Methods and Results

Forty-three patients with pancreatic cancer who underwent pancreaticoduodenectomy at our hospital between April 1, 2018, and March 31, 2021, were included. We extracted DNA from noncancerous areas of residual specimens after pancreaticoduodenectomy and determined PNPLA3 and TM6SF2 gene polymorphisms using real-time polymerase chain reaction. SLD was defined as a liver with an attenuation value of ≤40 HU or a liver-to-spleen ratio of ≤0.9 on computed tomography. We defined high hepatic fibrosis indexes (HFI) instead of steatohepatitis as a Fibrosis-4 index of ≥2.67 or nonalcoholic fatty liver disease fibrosis score of ≥0.675 in patients with SLD. The cumulative incidence of SLD (P = 0.299) and high HFI (P = 0.987) after pancreaticoduodenectomy were not significantly different between the PNPLA3 homozygous and minor allele groups. The incidences of high HFI at 1 year after pancreaticoduodenectomy were 16.8% and 27.0% in the TM6SF2 major homozygous and minor allele groups, respectively, with a significant difference in the cumulative incidence (P = 0.046).

Conclusion

The TM6SF2 minor allele may contribute to steatohepatitis development after pancreaticoduodenectomy.

Risk factors of developing nonalcoholic fatty liver disease after pancreatic resection: a systematic review and meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) occurs in 10% to 40% of patients after pancreatic resection. Pancreatic exocrine insufficiency (PEI) is thought to be closely associated with NAFLD; however, the mechanism of NAFLD is not clearly understood. We perform a systematic review and meta-analysis to better understand the risk factors of NAFLD.

METHODS

A systematic literature search was performed in the MEDLINE database. Studies focused on the risk factors associated with NAFLD in patients undergoing pancreatectomy. The odds ratios (ORs) denoting the association of risk factors with NAFLD after resection were curated.

RESULTS

Of 814 published articles, 26 studies met the inclusion criteria. Combined, these studies included clinical data on 4055 patients. The pooled incidence of NAFLD was 29% (23%-35%). Among the various risk factors analyzed, the following had a significant likelihood of NAFLD on forest plot analysis: female gender (OR, 2.44), pancreatic ductal adenocarcinoma (OR, 2.11), portal vein or superior mesenteric vein resection (OR, 1.99), dissection of nerve plexus around the superior mesenteric artery (OR, 1.93), and adjuvant chemotherapy (OR, 1.58). Only 2 studies investigated 2 different measurements of quantitative PEI, which could not be used for analysis. Owing to heterogeneity of studies, pancreatic remanent volume, which is considered a marker for PEI could not be evaluated. Pancreatic enzyme replacement therapy (PERT) was not associated with NAFLD.

CONCLUSION

Numerous factors are associated with NAFLD after pancreatectomy. Previous research shows that PEI may be associated with NAFLD; however, this could not be compared in our meta-analysis. Further research is required to study the role of PERT in NAFLD.

Development of de novo nonalcoholic fatty liver disease following pancreatectomy

De novo non-alcoholic fatty liver disease (NAFLD) after pancreatectomy is a recognized phenomenon; however, its pathophysiology is poorly understood. This study aimed to determine the incidence and identify peri-operative risk factors for the development of de novo NAFLD within various pancreatectomy groups. This single-center retrospective cohort study included patients who underwent pancreatectomy between 2000 and 2020. The incidence rate of de novo NAFLD and time to diagnosis were recorded across patients with malignant versus benign indications for pancreatectomy. The overall incidence of de novo NAFLD after pancreatectomy was 17.5% (24/136). Twenty-one percent (20/94) of patients with malignant indications for surgery developed NAFLD compared to 9.5% (4/42) with benign indications (P = .09). Time to development of hepatic steatosis in the malignant group was 26.4 months and was significantly shorter by an average of 6 months when compared to the benign group (32.8 months, P = .03). Higher pre-operative body mass index was associated with new-onset NAFLD (P = .03). Pre-operative body mass index is a significant predictor for de novo NAFLD and highlights a group that should be closely monitored post-operatively, especially after resections for pancreatic malignancy.

De novo non-alcoholic fatty liver disease after pancreatectomy: A systematic review

BACKGROUND

As operative techniques and mortality rates of pancreatectomy have improved, there has been a shift in focus to maintaining and improving the nutritional status of these patients as we continue to learn more about post-operative complications. Although pancreatic endocrine and exocrine insufficiencies are known complications of pancreatectomy, increased longevity of these patients has also led to a higher incidence of de novo fatty liver disease which differs from traditional fatty liver disease given the lack of metabolic syndrome.

AIM

To identify and summarize patterns and risk factors of post-pancreatectomy de novo fatty liver disease to guide future management.

METHODS

We performed a database search on PubMed selecting papers published between 2001 and 2022 in the English language. PubMed was last accessed 1 June 2022.

RESULTS

Various factors influence the development of de novo fatty liver including indication for surgery (benign vs malignant), type of pancreatectomy, amount of pancreas remnant, and peri-operative nutritional status. With an incidence rate up to 75%, de novo non-alcoholic fatty liver disease (NAFLD) can develop within 12 mo after pancreatectomy and various risk factors have been established including pancreatic resection line and remnant pancreas volume, peri-operative malnutrition and weight loss, pancreatic exocrine insufficiency (EPI), malignancy as the indication for surgery, and postmenopausal status.

CONCLUSION

Since majority of risk factors leads to EPI and malnutrition, peri-operative focus on nutrition and enzymes replacement is key in preventing and treating de novo NAFLD after pancreatectomy.

Cellular Mechanisms of Liver Fibrosis

The liver is a central organ in the human body, coordinating several key metabolic roles. The structure of the liver which consists of the distinctive arrangement of hepatocytes, hepatic sinusoids, the hepatic artery, portal vein and the central vein, is critical for its function. Due to its unique position in the human body, the liver interacts with components of circulation targeted for the rest of the body and in the process, it is exposed to a vast array of external agents such as dietary metabolites and compounds absorbed through the intestine, including alcohol and drugs, as well as pathogens. Some of these agents may result in injury to the cellular components of liver leading to the activation of the natural wound healing response of the body or fibrogenesis. Long-term injury to liver cells and consistent activation of the fibrogenic response can lead to liver fibrosis such as that seen in chronic alcoholics or clinically obese individuals. Unidentified fibrosis can evolve into more severe consequences over a period of time such as cirrhosis and hepatocellular carcinoma. It is well recognized now that in addition to external agents, genetic predisposition also plays a role in the development of liver fibrosis. An improved understanding of the cellular pathways of fibrosis can illuminate our understanding of this process, and uncover potential therapeutic targets. Here we summarized recent aspects in the understanding of relevant pathways, cellular and molecular drivers of hepatic fibrosis and discuss how this knowledge impact the therapy of respective disease.

Metformin Attenuates Ischemia-reperfusion Injury of Fatty Liver in Rats Through Inhibition of the TLR4/NF-κB Axis

Background

Donor organs for liver transplantation may often have fatty liver disease, which confers a higher sensitivity to ischemia/reperfusion injury. At present, there is no effective treatment for the condition. Evidence has suggested that metformin, the first-line medication for diabetes, has protective effects against many disorders. However, the potential role of metformin in ischemia/reperfusion injury in fatty liver disease remains unclear.

Aims

To examine the effect of metformin treatment during ischemia/reperfusion injury in fatty liver and determine the possible mechanisms.

Study Design

Animal experimentation.

Methods

Sprague-Dawley male rats were fed a high-fat diet (520 kcal/100 g) for 14 weeks and then were subjected to the orthotopic autologous liver transplantation model. Sections of liver tissue were stained with hematoxylin and eosin to visualize the damage. Blood and liver samples were used to analyze the related proteins and components involved in the inflammatory signaling pathway.

Results

We found that metformin significantly ameliorated the ischemia/reperfusion injury of the fatty liver through a reduction in alanine aminotransferase/aspartate aminotransferase concentrations in the serum and a decrease in dead cells, as shown by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (p<0.05). In addition, metformin significantly attenuated interleukin (IL)-6, IL-1β, and tumor necrosis factor-α production and increased the expression of active caspase-3 and Bax in the liver (p<0.05). Mechanistically, metformin suppressed the activation of toll-like receptor 4 (TLR4)/NF-κB signaling (p<0.05), resulting in a decreased inflammatory response and apoptosis.

Conclusion

Our findings demonstrated that metformin attenuated ischemia/reperfusion injury in fatty liver disease via the TLR4/NF-κB axis, suggesting that metformin could have potential therapeutic applications in ischemia/reperfusion injury associated with liver transplantation.

Clinical Characteristics and Risk Factors for the Development of Postoperative Hepatic Steatosis After Total Pancreatectomy

OBJECTIVES

The occurrence of hepatic steatosis after pancreatectomy is known to be associated with the remnant pancreatic function. However, other risk factors for hepatic steatosis after pancreatectomy remain unknown. The aims of this study were to identify other risk factors in addition to the remnant pancreatic function and elucidate the relationship between postoperative hepatic steatosis and pancreatic exocrine insufficiency in totally pancreatomized patients.

METHODS

Forty-three patients who underwent total pancreatectomy were analyzed. Hepatic steatosis was defined as the attenuation of unenhanced computed tomography values. Clinical findings and laboratory data were compared between patients with and without hepatic steatosis.

RESULTS

Sixteen (37.2%) patients developed hepatic steatosis after total pancreatectomy, with marked declines in the Controlling Nutritional Status score and body mass index. Multiple linear regression analysis revealed that the attenuation of computed tomography values was correlated with female sex (P = 0.002), early postoperative serum albumin levels (P = 0.003), and pancreatic enzyme replacement therapy with high-dose pancrelipase (P = 0.032).

CONCLUSIONS

Postoperative hepatic steatosis after pancreatectomy is associated with sex, malnutrition, and pancreatic exocrine insufficiency. High-dose pancreatic enzyme replacement therapy may have preventive effects on hepatic steatosis occurring after pancreatectomy.

Small intestinal bacterial overgrowth and toll-like receptor signaling in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is multifactorial. There is sparse literature on the role of small intestinal bacterial overgrowth (SIBO) and toll-like receptor (TLR) signaling in NAFLD. The present study evaluated the relationship of SIBO with expression of TLR signaling genes in patients with NAFLD.

METHODS

A total of 142 subjects composed of NAFLD (n = 60, mean age 38.7 ± 10.4 years), chronic viral hepatitis (CVH) (n = 32, mean age 39.5 ± 10.6 years), and healthy volunteers (n = 50, mean age 36.56 ± 4.2 years) were enrolled in the study. Duodenal fluid was taken endoscopically in 32 prospective patients with NAFLD for evaluation of SIBO. Hepatic mRNA expression of TLR4, CD14, TLR2, NF-κβ, and MD2 and protein expression of TLR4 and TLR2 were studied in 64 patients (NAFLD = 32, CVH = 32) by RT-PCR and immunohistochemistry, respectively. Serum levels of TNF-α, adiponectin, insulin, and endotoxins were also evaluated.

RESULTS

Small intestinal bacterial overgrowth was present in 12 (37.5%) out of 32 patients with NAFLD with Escherichia coli as the predominant bacterium. In comparison with those without SIBO, patients with SIBO had significantly higher endotoxin levels and higher CD14 mRNA, nuclear factor kappa beta mRNA, and TLR4 protein expression. Patients with NASH had significantly higher endotoxin levels and higher intensity of TLR4 protein expression in comparison with patients without NASH. Serum levels of TNF-α, endotoxins, and insulin were significantly higher and of adiponectin lower in NAFLD in comparison with CVH and healthy volunteers.

CONCLUSIONS

Our study provides the first direct evidence of role of SIBO and endotoxemia and its relation with TLR signaling genes and liver histology in patients with NAFLD.

Pathophysiology after pancreaticoduodenectomy

Pancreaticoduodenectomy (PD) will result in removal of important multiorgans in upper intestinal tract and subsequently secondary physiologic change. In the past, surgeons just focused on the safety of surgical procedure; however, PD is regarded as safe and widely applied to treatment of periampullary lesions. Practical issues after PD, such as, effect of duodenectomy, metabolic surgery-like effect, alignment effect of gastrointestinal continuity, and non-alcoholic fatty liver disease were summarized and discussed.

Risks of misinterpretation in the evaluation of the effect of fruit-based drinks in postprandial studies

It has been suggested that some fruit-based drinks (FBD) may delay the onset of postprandial stress, which is involved in the pathogenesis of many diseases. The majority of the studies, which have investigated the effects of FBD on postprandial stress, involved a placebo that was a drink with the same content in sugars or carbohydrates of the FBD, but without the bioactive antioxidant compounds. These studies were aimed more at evaluating the effect of the antioxidants rather than the effect of the FBD as a whole. Only 4 studies compared the effect of FBD with water as control and did not support the hypothesis that FBD could inhibit postprandial dysmetabolism, as well as the studies that compared the effect of orange juice and cola. Overall, the results suggest a complex relationship between postprandial dysmetabolism, inflammation, and oxidative stress. Furthermore, the inflammatory and oxidative stress markers need further analytical validation and normal ranges should be established in order to reach a firm conclusion. Finally, caution should be taken in the interpretation of the effect of FBD in postprandial studies and the reviewed results suggest that dietary recommendations should aim to limit rather than increase sugar-sweetened beverages consumption.

Paradoxical impact of the remnant pancreatic volume and infectious complications on the development of nonalcoholic fatty liver disease after pancreaticoduodenectomy

BACKGROUND

The aim of the present study was to evaluate perioperative risk factors for development of nonalcoholic fatty liver disease (NAFLD) after pancreaticoduodenectomy (PD), paying special attention to remnant pancreatic volume (RPV) and postoperative infection.

METHODS

We reviewed the charts of 110 patients who had been followed more than 6 months after PD. These patients were classified into the two groups according to RPV measured by CT volumetry at one month: large-volume group (LVG) (10 ml or more, n = 75) and small-volume group (SVG) (less than 10 ml, n = 35).

RESULTS

Nonalcoholic fatty liver disease developed in 44 (40.0%), being significantly higher in SVG than in LVG: 54.2% vs. 33.3% (P = 0.037). SVG was characterized as significantly higher incidence of pancreatic adenocarcinoma, while LVG was characterized as significantly higher incidences of soft pancreas, postoperative infection and pancreatic fistula. In LVG, the incidence of NAFLD was significantly higher in patients with suspicion of infection than in those without it: 45.2% vs. 18.1% (P = 0.014), while not different in SVG. By multivariate analysis, independent risk factor was determined as RPV and suspicion of infection in the whole patients, and in LVG it was suspicion of infection, while in SVG it was not identified.

CONCLUSION

After PD, RPV and status of postoperative infection paradoxically influenced the development of NAFLD.