Pediatric liver transplantation: a North American perspective

Not only a small liver - The pathologist's perspective in the pediatric liver transplant setting

Pediatric liver transplantation represents a safe and long-lasting treatment option for various disease types, requiring the pathologist’s input. Indeed, an accurate and timely diagnosis is crucial in reporting and grading native liver diseases, evaluating donor liver eligibility and identifying signs of organ injury in the post-transplant follow-up. However, as the procedure is more frequently and widely performed, deceptive and unexplored histopathologic features have emerged with relevant consequences on patient management, particularly when dealing with long-term treatment and weaning of immunosuppression.

In this complex and challenging scenario, this review aims to depict the most relevant histopathologic conditions which could be encountered in pediatric liver transplantation. We will tackle the conditions representing the main indications for transplantation in childhood as well as the complications burdening the post-transplant phases, either immunologically (i.e., rejection) or non-immunologically mediated. Lastly, we hope to provide concise, yet significant, suggestions related to innovative pathology techniques in pediatric liver transplantation.

Early life high-fat diet exposure maintains glucose tolerance and insulin sensitivity with a fatty liver and small brain size in the adult offspring

Diet during pregnancy has long lasting consequences on the offspring, warranting a study on the impact of early exposure to a high fat diet on the adult offspring. We hypothesized that a prenatal n-6 enriched diet will have adverse metabolic outcomes on the adult offspring that may be reversed with a postnatal n-3 enriched diet. To test this hypothesis, we examined the adult offspring from three groups: (1) n-6 group: during gestation and lactation, dams consumed an n-6 polyunsaturated fatty acid enriched diet, (2) n-3 group: gestational n-6 diet was followed by an n-3 enriched diet during lactation, and (3) a control (CD) group that received standard diet throughout gestation and lactation. Offspring from all groups weaned to a control diet ad libitum. Beginning at postnatal day 2 (P < .03) and persisting at 360 days in males (P < .04), an increase in hypothalamic AgRP expression occurred in the n-6 and n-3 groups, with an increase in food intake (P = .01), and the n-3 group displaying lower body (P < .03) and brain (P < .05) weights. At 360 days, the n-6 and n-3 groups remained glucose tolerant and insulin sensitive, with increased phosphorylated-AMP-activated protein kinase (P < .05). n-6 group developed hepatic steatosis with reduced hepatic reflected as higher plasma microRNA-122 (P < .04) that targets pAMPK. We conclude that early life exposure to n-6 and n-3 led to hypothalamic AgRP-related higher food intake, with n-6 culminating in a fatty liver partially mitigated by postnatal n-3. While both diets preserved glucose tolerance and insulin sensitivity, postnatal n-3 displayed detrimental effects on the brain.