Duodenal morphometry and small bowel permeability in children with portal hypertension

Intestinal Barrier Function in the Pathogenesis of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The mechanisms involved in NAFLD onset are complicated and multifactorial. Recent literature has indicated that altered intestinal barrier function is related to the occurrence and progression of liver disease. The intestinal barrier is important for absorbing nutrients and electrolytes and for defending against toxins and antigens in the enteric environment. Major mechanisms by which the intestinal barrier influences the development of NAFLD involve the altered epithelial layer, decreased intracellular junction integrity, and increased intestinal barrier permeability. Increased intestinal permeability leads to luminal dysbiosis and allows the translocation of pathogenic bacteria and metabolites into the liver, inducing inflammation, immune response, and hepatocyte injury in NAFLD. Although research has been directed to NAFLD in recent decades, the pathophysiological changes in NAFLD initiation and progression are still not completely understood, and the therapeutic targets remain limited. A deeper understanding on the correlation between NAFLD pathogenesis and intestinal barrier regulation must be attained. Therefore, in this review, the components of the intestinal barrier and their respective functions and disruptions during the progression of NAFLD are discussed.

Pediatric non-cirrhotic portal hypertension: Endoscopic outcome and perspectives from developing nations

Non-cirrhotic portal hypertension (NCPH) forms an important subset of portal hypertension in children. Variceal bleed and splenomegaly are their predominant presentation. Laboratory features show cytopenias (hypersplenism) and preserved hepatic synthetic functions. Repeated sessions of endoscopic variceal ligation or endoscopic sclerotherapy eradicate esophageal varices in almost all cases. After variceal eradication, there is an increased risk of other complications like secondary gastric varices, cholangiopathy, colopathy, growth failure, especially in extra-hepatic portal vein obstruction (EHPVO). Massive splenomegaly-related pain and early satiety cause poor quality of life (QoL). Meso-Rex bypass is the definitive therapy when the procedure is anatomically feasible in EHPVO. Other portosystemic shunt surgeries with splenectomy are indicated when patients present late and spleen-related issues predominate. Shunt surgeries prevent rebleed, improve growth and QoL. Non-cirrhotic portal fibrosis (NCPF) is a less common cause of portal hypertension in children in developing nations. Presentation in the second decade, massive splenomegaly and patent portal vein are discriminating features of NCPF. Shunt surgery is required in severe cases when endotherapy is insufficient for the varices. Congenital hepatic fibrosis (CHF) presents with firm palpable liver and splenomegaly. Ductal plate malformation forms the histological hallmark of CHF. CHF is commonly associated with Caroli’s disease, renal cysts, and syndromes associated with neurological defects. Isolated CHF has a favourable prognosis requiring endotherapy. Liver transplantation is required when there is decompensation or recurrent cholangitis, especially in Caroli’s syndrome. Combined liver-kidney transplantation is indicated when both liver and renal issues are present.

Gut Microbiome: A Potential Modifiable Risk Factor in Biliary Atresia

Biliary atresia (BA) is a fibro-obliterative condition of the biliary tree, presenting in infancy. The bilioenteric conduit formed at Kasai portoenterostomy (KPE), achieves restoration of bile flow in approximately 60% of infants. Even if the operation is successful, cirrhosis and its associated complications are, however, common. BA remains the leading cause for liver transplantation (LT) in children. Antibiotic, choleretic, and steroid therapy post-KPE have not convincingly reduced LT rates. Advances in molecular technology have enabled characterisation of the encoded genes of the gut microbiota (gut microbiome). The gut microbiome plays an important role in host metabolism, nutrition, and immune function, with alterations in its diversity and/or composition, known as dysbiosis, being described in disease states, including liver disease. Liver-gut microbiome exploration in adulthood largely focuses on nonalcoholic liver disease, cirrhosis (mainly alcohol- or viral-based aetiology) and cholestatic liver diseases (eg, primary sclerosing cholangitis), with microbial signatures correlating to disease severity. Investigation of the gut microbiota in BA had been limited to culture-based methodology, but molecular studies are emerging, and although in their infancy, highlight a potential pathogenic role for Enterobacteriaceae and Streptococcus, and a potential beneficial role for Bifidobacteria. Bacterial translocation, and the production of gut microbiome-derived metabolites, are key host-microbiome-mechanistic pathways in liver disease pathogenesis. Microbiome-targeted therapeutics for liver disease are in development, with faecal microbiota transplantation showing promise in cirrhosis. Could the gut microbiome be a novel modifiable risk factor in BA, reducing the need for LT?

Prevalence, nature, and predictors of colonic changes in children with extrahepatic portal vein obstruction

BACKGROUND AND AIMS

The medical literature on colonic changes in children with extrahepatic portal venous obstruction (EHPVO) is limited. We evaluated EHPVO children for prevalence, nature, and relation of colonic changes with disease duration, extent of splenoportal axis (SPA) thrombosis, portal hypertensive gastropathy (PHG), and esophageal varices (EVs). The correlation between histologic and endoscopic changes was studied.

METHODS

Subjects were evaluated by colonoscopy with ileoscopy and biopsy sampling, clinico-laboratory profiles, and SPA imaging. Colonic changes were classified as varices (rectal/colonic) and portal hypertensive colopathy (PHC; colitis-like or vascular lesions). Morphometric analysis of colonic biopsy specimens was performed.

RESULTS

Fifty-four children (median age, 12 years [range, 8-15]; hematochezia in 9 [16.6%]) were evaluated. Rectal and colonic varices were seen in 51 (94%) and 2 (3.7%) cases, respectively. Seventy-five percent of patients had PHC, and colitis-like lesions were more common than vascular lesions (36/40 vs 23/40; P = .001). Colopathy changes were pancolonic in 52.5%, left-sided in 42.5%, and right-sided in 5% of cases. Sixteen percent of patients (8/49) had ileal changes. Children with PHC had PHG more often (90% vs 57%; P = .01), more endotherapy sessions (mean 6 [range, 4-8] vs 2 [range, 1-4]; P = .03), and large EVs less often (12.5% vs 43%; P = .02) than those without colopathy. The extent of SPA thrombosis was similar in patients with and without PHC. The number of capillaries per crypt was higher in EHPVO than in control subjects. Morphometric changes had no correlation with endoscopy.

CONCLUSIONS

Most EHPVO children had colonic changes, and 16% had ileopathy. "Colitis-like" changes and left-side involvement were more common. Patients with PHG and eradicated EVs had a higher risk of PHC.