Reduced aluminum contamination decreases parenteral nutrition associated liver injury

Review of parenteral nutrition-associated liver disease

Parenteral nutrition has been widely used in patients whose gastrointestinal tract is anatomically or physiologically unavailable for sufficient food intake. It has been considered lifesaving but is not without adverse effects. It has been proven to cause liver injury through different mechanisms. We present a review of parenteral nutrition-associated liver disease.

Aluminum Exposure from Parenteral Nutrition: Early Bile Canaliculus Changes of the Hepatocyte

Background: Neonates on long-term parenteral nutrition (PN) may develop parenteral nutrition-associated liver disease (PNALD). Aluminum (Al) is a known contaminant of infant PN, and we hypothesize that it substantially contributes to PNALD. In this study, we aim to assess the impact of Al on hepatocytes in a piglet model. Methods: We conducted a randomized control trial using a Yucatan piglet PN model. Piglets, aged 3–6 days, were placed into two groups. The high Al group (n = 8) received PN with 63 µg/kg/day of Al, while the low Al group (n = 7) received PN with 24 µg/kg/day of Al. Serum samples for total bile acids (TBA) were collected over two weeks, and liver tissue was obtained at the end of the experiment. Bile canaliculus morphometry were studied by transmission electron microscopy (TEM) and ImageJ software analysis. Results: The canalicular space was smaller and the microvilli were shorter in the high Al group than in the low Al group. There was no difference in the TBA between the groups. Conclusions: Al causes structural changes in the hepatocytes despite unaltered serum bile acids. High Al in PN is associated with short microvilli, which could decrease the functional excretion area of the hepatocytes and impair bile flow.

Pediatric intestinal failure-associated liver disease

PURPOSE OF REVIEW

The goal of this review is to provide updates on the definition, pathophysiology, treatment, and prevention of intestinal failure-associated liver disease (IFALD) that are relevant to care of pediatric patients.

RECENT FINDINGS

Current literature emphasizes the multifactorial nature of IFALD. The pathogenesis is still largely unknown; however, molecular pathways have been identified. Key to these pathways are proinflammatory cytokines involved in hepatic inflammation and bile acids synthesis such as Toll-like receptor 4 and farnesoid X receptor, respectively. Research for prevention and treatment is aimed at alleviating risk factors associated with IFALD, principally those associated with parental nutrition. Multiple nutrients and amino acids are relevant to the development of IFALD, but lipid composition has been the primary focus. Lipid emulsions with a lower ratio of omega-6-to-omega-3 polyunsaturated fatty acids (FAs) appear to improve bile flow and decrease intrahepatic inflammation. Long-term consequences of these alternative lipid emulsions are yet to be determined.

SUMMARY

IFALD remains the greatest contributor of mortality in patients with intestinal failure. Many factors contribute to its development, namely, alterations in the gut microbiome, sepsis, and lack of enteral intake. Novel combinations of lipid formulations are promising alternatives to purely soy-based formulas to reduce cholestasis.

Parenteral Nutrition and Intestinal Failure

Severe short bowel syndrome (SBS) is a major cause of chronic (Type 3) intestinal failure (IF) where structural and functional changes contribute to malabsorption and risk of micronutrient deficiencies. Chronic IF may be reversible, depending on anatomy and intestinal adaptation, but most patients require long-term nutritional support, generally in the form of parenteral nutrition (PN). SBS management begins with dietary changes and pharmacologic therapies taking into account individual anatomy and physiology, but these are rarely sufficient to avoid PN. New hormonal therapies targeting intestinal adaptation hold promise. Surgical options for SBS including intestinal transplant are available, but have significant limitations. Home PN (HPN) is therefore the mainstay of treatment for severe SBS. HPN involves chronic administration of macronutrients, micronutrients, fluid, and electrolytes via central venous access in the patient's home. HPN requires careful clinical and biochemical monitoring. Main complications of HPN are related to venous access (infection, thrombosis) and metabolic complications including intestinal failure associated liver disease (IFALD). Although HPN significantly impacts quality of life, outcomes are generally good and survival is mostly determined by the underlying disease. As chronic intestinal failure is a rare disease, registries are a promising strategy for studying HPN patients to improve outcomes.

Effects of aluminum chloride on serum proteins, bilirubin, and hepatic trace elements in chickens

The aim of this study was to reveal the effects of aluminum chloride (AlCl3) on the hepatic metabolism function and trace elements’ distribution. Two hundred healthy male chickens (1 day old) were intraperitoneally administered with AlCl3 (0, 18.31, 27.47, and 36.62 mg kg−1 day−1 of Al3+) consecutively for 3 days. Then the chickens were allowed to rest for 1 day. The cycle lasted four days. The cycle was repeated 15 times (60 days). The contents of serum total protein (TP), albumin (ALB), total bilirubin (TBI), direct bilirubin (DBI), hepatic aluminum (Al), copper (Cu), iron (Fe), and zinc (Zn) were examined. The results showed that the contents of serum TP and ALB and hepatic Fe and Zn decreased and the contents of serum TBI and DBI and hepatic Al and Cu increased in the chickens with AlCl3. This indicates that chronic administration of AlCl3 impairs the hepatic metabolism function and disorders the hepatic trace elements’ distribution.

Pediatric parenteral nutrition-associated liver disease and cholestasis: Novel advances in pathomechanisms-based prevention and treatment

Parenteral nutrition constitutes a life-saving therapeutic tool in patients unable to ingest/absorb oral or enteral delivered nutrients. Liver function tests abnormalities are a common therapy-related complication, thus configuring the so-called Parenteral Nutrition Associated Liver Disease (PNALD) or cholestasis (PNAC). Although the damage is frequently mild, and resolves after discontinuation of parenteral nutrition, in some cases it progresses into cirrhotic changes, especially in neonates and infants. We present a literature review focusing on the pathogenetic mechanisms-driven prevention and therapies for the cases where parenteral nutrition cannot be discontinued. Ursodeoxycholic acid has been proposed in patients with cholestatic hepatopathy, but its efficacy needs to be better established. Little evidence is available on efficacy of anti-oxidants, antibiotics, probiotics and anti TNFα. Lipid emulsions based on fish oil with a high content of long-chain polyunsaturated fatty acids ω-3 appear effective both in decreasing intrahepatic inflammation and in improving biliary flow. Most recent promising variations such as soybean/MCT/olive/fish oil emulsion [third generation lipid emulsion (SMOFlipid)] are under investigation. In conclusion, we remark the emergence of a number of novel pathomechanisms underlying the severe liver impairment damage (PNALD and PNAC) in patients treated with parenteral nutrition. Only few traditional and innovative therapeutic strategies have hitherto been shown promising.

Aluminum contamination in parenteral products

PURPOSE OF REVIEW

In 1986, the US Food and Drug Administration issued an aluminum mandate in hopes of minimizing patient exposure to aluminum contaminates contained in parenteral nutrition additives. The purpose of this article is to revisit the status of aluminum contamination as it relates to parenteral nutrition and to survey the recent literature to determine if any new findings have emerged. A special emphasis will be placed on the complications associated with aluminum toxicity.

RECENT FINDINGS

In addition to metabolic bone disease, patients with aluminum toxicity are also prone to other complications such as neurodevelopmental delays and cholestasis. Other potentially serious consequences, including osteoporosis, growth failure, and dementia, can arise years after the initial exposure to aluminum, showing that preventing toxicity is imperative.

SUMMARY

Unlike the rapid response to eliminating aluminum toxicity in the dialysis patient population, similar successes have not been realized in patients receiving parenteral nutrition solutions. Product formulation changes have been slow to emerge from manufacturers. It remains the responsibility of healthcare practitioners to recognize the patient populations at risk for toxicity and act accordingly. Monitoring aluminum status and purchasing products known to possess the least amount of aluminum are two such approaches.

Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts

Abstract Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007) . Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of "total Al"assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al(+3) to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)(+2) and Al(H2O)6 (+3)] that after complexation with O2(•-), generate Al superoxides [Al(O2(•))](H2O5)](+2). Semireduced AlO2(•) radicals deplete mitochondrial Fe and promote generation of H2O2, O2 (•-) and OH(•). Thus, it is the Al(+3)-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer's disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances.

Plasma Aluminum Concentrations in Pediatric Patients Receiving Long-Term Parenteral Nutrition

BACKGROUND

Patients receiving long-term parenteral nutrition (PN) are at increased risk of aluminium (Al) toxicity because of bypass of the gastrointestinal tract during PN infusion. Complications of Al toxicity include metabolic bone disease (MBD), Al-associated encephalopathy in adults, and impaired neurological development in preterm infants. Unlike the United States, there are no regulations regarding Al content of large- and small-volume parenterals in Canada. We, therefore, aimed to present our data on plasma Al concentration and Al intake from our cohort of pediatric patients receiving long-term PN.

METHODS

Plasma Al concentration was retrospectively gathered from the patient charts of all 27 patients with intestinal failure (IF) receiving long-term PN at The Hospital for Sick Children, Toronto, Canada, and compared with age- and sex-matched controls recruited for comparison. In addition, Al concentration was measured in PN samples collected from 10 randomly selected patients with IF and used to determine their Al intake.

RESULTS

The plasma Al concentration of patients with IF receiving long-term PN was significantly higher than that of control participants (1195 ± 710 vs 142 ± 63 nmol/L; P < .0001). In the subgroup of 10 patients for whom Al intake from their PN solution was determined, mean ± SD Al intake from PN was 15.4 ± 15 µg/kg, 3 times the Food and Drug Administration upper recommended intake level, and Al intake was significantly related to plasma Al concentration (P = .02, r (2) = 0.52).

CONCLUSION

Pediatric patients receiving long-term PN for IF in Canada are at risk for Al toxicity.

Review and clinical update on parenteral nutrition-associated liver disease

Parenteral nutrition-associated liver disease (PNALD) is a complex disease that is diagnosed by clinical presentation, biochemical markers of liver injury, concurrent use of parenteral nutrition (PN), and negative workup for other causes of liver disease. Since the first case of PNALD was reported more than 30 years ago, clinicians have had few effective treatments for PNALD, and when disease progressed to liver cirrhosis, it was historically associated with poor outcomes. Within the past 5 years, there has been much excitement about new treatments for PNALD, including use of both parenteral and enteral ω-3 polyunsaturated long-chain fatty acids (ω-3 PUFA) as well as restricting dosing of ω-6 PUFA. Scientists are also interested in uncovering the mechanisms associated with liver injury seen in PNALD. This article reviews the recent literature relating to the pathophysiology and treatment of PNALD.