Alan L. Buchman

Parenteral nutrition is associated with intestinal morphologic and functional changes in humans

BACKGROUND Numerous animal studies have demonstrated intestinal villus atrophy occurs when luminal nutrition is withheld and total parenteral nutrition (TPN) is provided. Intestinal morphologic and functional changes have not been well studied in humans during TPN. METHODS Eight normal volunteers were hospitalized in the Clinical Research Center for 3 weeks. The subjects received TPN as an exclusive means of nutritional support for 14 days followed by 5 days of enteral refeeding with either a standard or a glutamine and arginine-supplemented formula. Endoscopic jejunal biopsies were taken before and after TPN and after enteral refeeding. Intestinal morphology was examined by light and transmission electron microscopy. Mucosa DNA, RNA, and protein concentrations were measured. Lactose breath hydrogen and intestinal permeability testing (urinary lactulose and mannitol excretion after an oral dose) were performed before and after TPN and after enteral refeeding. RESULTS Total mucosal thickness decreased after TPN (645 +/- 19 to 512 +/_ 19 microns, p = .003) and increased significantly towards baseline after enteral refeeding (575 +/- 19 microns, p = .04). The change was related solely to villus height; crypt depth was unaffected. Villus cell count decreased from 179 +/- 15 to 163 +/- 12 after TPN (p = .03) and increased after enteral refeeding to 176 +/- 21 (p = .06). Crypt cell count was unaffected by TPN or refeeding. A nonsignificant decrease in the mitotic index after TPN was seen. Intracellular edema developed during TPN and resolved with enteral refeeding. The urinary lactulose-mannitol ratio increased with TPN [0.06 +/- 0.03 to 0.11 +/- 0.05 after TPN and 0.14 +/_ 0.09 after short-term enteral refeeding (p = .05)], indicating increased intestinal permeability. The urinary lactulose-mannitol ratio was significantly greater after refeeding with standard formula than the free amino acid peptide formula with glutamine and arginine (0.20 +/- 0.05, vs 0.08 +/- 0.01, p = .05). No significant differences were noted in mucosal RNA, DNA, protein, DNA-protein or RNA-DNA rations or breath hydrogen after lactose ingestion after either TPN or enteral refeeding. No significant difference in plasma glutamine was found during TPN (462.7 +/ 38.7 vs 491.8 +/- 46.1 mumol/L) or after enteral refeeding (457.3 +/- 51.4 mumol/L). CONCLUSIONS Intestinal morphologic and functional changes occur in human for whom TPN is the sole nutritional source, although the findings in humans are substantially less significant than observed in animal models. The loss of mucosal structure may be sufficient to cause increased intestinal permeability, the clinical significance of which remains to be defined. Enteral nutrition is important in restoring and probably preventing morphologic intestinal changes associated with TPN, and a peptide and free amino acid-based formula supplemented with glutamine and arginine may have some added role. Our findings also suggest sepsis is associated with gut adaptation rather than degradation.

Teduglutide (ALX-0600), a dipeptidyl peptidase IV resistant glucagon-like peptide 2 analogue, improves intestinal function in short bowel syndrome patients

Background and aims: Glucagon-like peptide 2 (GLP-2) may improve intestinal absorption in short bowel syndrome (SBS) patients with an end jejunostomy. Teduglutide (ALX-0600), a dipeptidyl peptidase IV resistant GLP-2 analogue, prolongs the intestinotrophic properties of GLP-2 in animal models. The safety and effect of teduglutide were investigated in SBS patients with and without a colon in continuity. Methods: Teduglutide was given subcutaneously for 21 days once or twice daily to 16 SBS patients in the per protocol investigational group, 10 with end jejunostomy (doses of 0.03 (n = 2), 0.10 (n = 5), or 0.15 (n = 3) mg/kg/day), one with <50% colon in continuity (dose 0.03 mg/kg/day), and five with ≥50% colon in continuity (dose 0.10 mg/kg/day). Nutrient balance studies, D-xylose tests, and intestinal mucosa biopsies were performed at baseline, on the last three days of treatment, and after three weeks of follow up. Pre-study fasting native GLP-2 levels were determined for the five patients with ≥50% colon in continuity. Results: Pooled across groups and compared with baseline, teduglutide increased absolute (+743 (477) g/day; p<0.001) and relative (+22 (16)%; p<0.001) wet weight absorption, urine weight (+555 (485) g/day; p<0.001), and urine sodium excretion (+53 (40) mmol/day; p<0.001). Teduglutide decreased faecal wet weight (−711 (734) g/day; p = 0.001) and faecal energy excretion (−808 (1453) kJ/day (−193 (347) kcal/day); p = 0.040). In SBS patients with end jejunostomy, teduglutide significantly increased villus height (+38 (45)%; p = 0.030), crypt depth (+22 (18)%; p = 0.010), and mitotic index (+115 (108)%; p = 0.010). Crypt depth and mitotic index did not change in colonic biopsies from SBS patients with colon in continuity. The most common side effects were enlargement of the stoma nipple and mild lower leg oedema. The improvements in intestinal absorption and decreases in faecal excretion noted after treatment had reversed after the drug free follow up period. A controlled study with a more robust design is ongoing in order to determine the optimal dosage of teduglutide for SBS patients to achieve the maximal effect and utility of this drug in clinical practice. Conclusion: Teduglutide, at three dose levels for 21 days, was safe and well tolerated, intestinotrophic, and significantly increased intestinal wet weight absorption in SBS patients with an end jejunostomy or a colon in continuity.

Side effects of corticosteroid therapy.

Background Corticosteroids have been used for the treatment of inflammatory bowel disease since the late 1940s. Upwards of 80% of patients may respond acutely to treatment with these medications, although 20% or more may be refractory and others become dependent on corticosteroid use to suppress disease activity. Side effects in the acute situation are relatively minor, although significant side effects (e.g., psychosis) have been encountered; the long-term use of corticosteroids is more problematic. This creates a milieu for the potential for serious and irreversible problems. These side effects are discussed in detail. The side effects from corticosteroids emulate from exogenous hypercortisolism, which is similar to the clinical syndrome of Cushings disease. Study PubMed search for years 1966–2000, authors personal manuscript/abstract files, and citations of known references. Conclusion Short-term corticosteroid use is associated with generally mild side effects, including cutaneous effects, electrolyte abnormalities, hypertension, hyperglycemia, pancreatitis, hematologic, immunologic, and neuropsychologic effects, although occasionally, clinically significant side effects may occur. Long-term corticosteroid use may be associated with more serious sequale, including osteoporosis, aseptic joint necrosis, adrenal insufficiency, gastrointestinal, hepatic, and ophthalmologic effects, hyperlipidemia, growth suppression, and possible congenital malformations.

Preliminary evaluation of safety and activity of recombinant human interleukin 11 in patients with active Crohn's disease

BACKGROUND & AIMS Recombinant human interleukin 11 (rhIL-11) is a cytokine with thrombocytopoietic activity and anti-inflammatory and mucosal protective effects. The objectives of this study were to investigate the safety and tolerability of rhIL-11 in patients with Crohns disease and to explore the effects of dose and schedule on platelet count and Crohns disease activity. METHODS A multicenter, double-masked, placebo-controlled, dose-escalation study of 76 patients with active Crohns disease was performed. Patients were randomized to receive subcutaneous placebo or rhIL-11 at doses of 5, 16, or 40 microgram. kg-1. wk-1 given 2 or 5 times weekly for 3 weeks. Clinical and laboratory safety data were recorded, and disease activity was measured at each visit. RESULTS Subcutaneous injection of rhIL-11 generally was well tolerated. Significantly greater increases in platelet counts were found among patients receiving rhIL-11 40 microgram. kg-1. wk-1 as 2 or 5 weekly doses and 16 microgram. kg-1. week-1 as 5 weekly doses compared with patients receiving placebo (P < 0.05). Patients receiving 16 microgram. kg-1. wk-1 had the highest clinical response rates, with a response seen in 42% of patients (5/12) receiving 5 weekly doses and 33% of patients (4/12) receiving 2 weekly doses, compared with 7% of patients (1/15) receiving placebo. CONCLUSIONS Short-term treatment with rhIL-11 is well tolerated in patients with active Crohns disease. The thrombocytopoietic effect of rhIL-11 seems to be both dose and schedule dependent and may be minimized with retained clinical benefit in Crohns disease at 16 microgram. kg-1. wk-1 given in 2 equal doses.

Choline Deficiency Causes Reversible Hepatic Abnormalities in Patients Receiving Parenteral Nutrition: Proof of a Human Choline Requirement: A Placebo-Controlled Trial

BACKGROUND Previous studies have shown that plasma free choline concentrations are significantly decreased in many long-term home total parenteral nutrition (TPN) patients. Furthermore, low choline status has been associated with both hepatic morphologic and hepatic aminotransferase abnormalities. A preliminary pilot study suggested choline-supplemented TPN may be useful in reversal of these hepatic abnormalities. METHODS Fifteen patients (10 M, 5 F) who had required TPN for > or =80% of their nutritional needs were randomized to receive their usual TPN (n = 8), or TPN to which 2 g choline chloride had been added (n = 7) for 24 weeks. Baseline demographic data were similar between groups. Patients had CT scans of the liver and spleen, and blood for plasma free and phospholipid-bound choline, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, gamma glutamyl transferase (GGT), bilirubin, serum lipids, complete blood count (CBC), and chemistry profile obtained at baseline, and weeks 2, 4, 6, 12, 16, 20, 24, and 34. CT scans were analyzed for Hounsfield unit (HU) densities. RESULTS There were no significant differences in any measured parameters after 2 weeks. However, at 4 weeks, a significant difference in liver HU between groups was observed (13.3+/-5.0 HU [choline] vs 5.8+/-5.2 HU [placebo], p = .04). This significant trend continued through week 24. Recurrent hepatic steatosis and decreased HU were observed at week 34, 10 weeks after choline supplementation had been discontinued. A significant increase in the liver-spleen differential HU was also observed in the choline group (10.6+/-6.2 HU [choline] vs 1.3+/-3.3 HU [placebo], p = .01). Serum ALT decreased significantly (p = .01 to .05) in the choline group vs placebo at weeks 6,12, 20, and 24. Serum AST was significantly decreased in the choline group by week 24 (p = .02). The serum alkaline phosphatase was significantly reduced in the choline group at weeks 2, 12, 20, 24, and 34 (p = .02 to 0.07). Total bilirubin was normal in these patients and remained unchanged during the study. Serum GGT tended to decrease more in the choline group, but the greater decrease was not statistically significant. CONCLUSIONS Choline deficiency is a significant contributor to the development of TPN-associated liver disease. The data suggest choline is a required nutrient for long-term home TPN patients.

Nutritional and Metabolic Considerations in the Etiology of Nonalcoholic Steatohepatitis

The aim of this study was to determine if a relationship exists between nonalcoholic steatohepatitis (NASH) and serum levels of free fatty acids, choline deficiency, or celiac disease. Forty-seven patients with liver biopsy proven NASH were enrolled. Total serum free fatty acids and anti-endomysial antibodies were determined in all patients, while plasma free and phospholipid-bound choline were determined in 29 patients. Total serum free fatty acid concentration correlated significantly with female gender and serum albumin concentration. Patients with severe fibrosis on liver biopsy had significantly greater serum concentration of free fatty acids than patients without severe fibrosis. Plasma free and phospholipid-bound choline levels were normal and no significant correlation was found between the concentration of plasma free or phospholipid bound choline, and the severity of liver damage. Only one of the 47 patients with NASH had a positive titer for the anti-endomysial antibody. In conclusion, increased serum concentrations of free fatty acids were found in NASH and were associated with development of more severe liver disease. Neither choline deficiency nor celiac sprue by anti-endomysial antibody testing was associated with NASH.

Videocapsule Endoscopy versus Barium Contrast Studies for the Diagnosis of Crohn's Disease Recurrence Involving the Small Intestine

OBJECTIVES:Historically, suspected Crohns disease (CD) has been evaluated with small bowel follow-through (SBFT) or enteroclysis (equally accurate). This study was undertaken to determine the accuracy of videocapsule endoscopy (VCE) in the diagnosis of CD relative to SBFT and clinical/laboratory indices of CD activity. Previous investigations have used VCE for the diagnosis of suspected CD in patients presenting with a variety of gastrointestinal symptoms. This is the first study to evaluate the occurrence of active disease in patients with known CD.METHODS:Thirty subjects (22 female, 8 male, aged 36.9 ± 14.2 yr); all with prior CD diagnosis made on the basis of standard criteria (5.5 ± 6.5 yr prior to study), in whom recurrent CD was suspected based on abdominal pain, diarrhea, anemia, and/or arthralgias. Subjects were studied in a prospective, blinded evaluation of VCE versus SBFT. SBFT was performed first; those with stricture and proximal bowel dilation were excluded from further study. For SBFT, studies were graded as grade 0 (normal), grade 1 (minimal nodularity, ulcerations, normal luminal diameter, < 5 cm involved), grade 2 (more extensive ulcers, minimal luminal narrowing, 5–10 cm involved), or grade 3 (fistula, skip areas, extensive ulceration, >10 cm involved). VCE was performed within 1 wk of SBFT. Serum was obtained for ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein), stool was obtained for α-1 antitrypsin, and the Harvey Bradshaw index of CD severity was calculated. VCE (digitalized video) was graded as grade 0 (normal), grade 1 (erythema, isolated villi loss), grade 2 (erosion, no ulcer), or grade 3 (ulcers, spontaneous bleeding, and/or stricture).RESULTS:Twelve patients were excluded for small bowel obstruction. VCE and SBFT scores highly correlated (r = 0.65; p = 0.001). Active CD was visualized in 21 of 30 patients with videocapsule endoscopy and in 20 of 30 patients with SBFT. Complete agreement occurred in 13 of 30 studies; 13 of 17 studies differed by one grade. SBFT found mucosal disease in 20 of 30 patients and VCE found mucosal disease in 21 of 30 patients. VCE found mucosal disease in 6 patients (5 in grade 1, 1 in grade 3) with normal SBFT. SBFT showed CD in 5 patients (all grade 1) with normal VCE. Neither VCE nor SBFT scores correlated with biological or clinical indices. Patient satisfaction was superior for VCE.CONCLUSIONS:VCE and SBFT are complementary for the diagnosis of CD. SBFT may be required to detect strictures as the videocapsule may not pass. However, some strictures may also be missed with SBFT. VCE is less invasive, less time-consuming for the patient than SBFT, and avoids radiation exposure, although reading time is greater for the gastroenterologist than the radiologist. Given that patients with clinically suspected CD recurrence may not have active disease, unnecessary and potentially harmful empiric therapy is not warranted without imaging.

A.S.P.E.N. Position Paper: Recommendations for Changes in Commercially Available Parenteral Multivitamin and Multi–Trace Element Products

The parenteral multivitamin preparations that are commercially available in the United States (U.S.) meet the requirements for most patients who receive parenteral nutrition (PN). However, a separate parenteral vitamin D preparation (cholecalciferol or ergocalciferol) should be made available for treatment of patients with vitamin D deficiency unresponsive to oral vitamin D supplementation. Carnitine is commercially available and should be routinely added to neonatal PN formulations. Choline should also be routinely added to adult and pediatric PN formulations; however, a commercially available parenteral product needs to be developed. The parenteral multi-trace element (TE) preparations that are commercially available in the U.S. require significant modifications. Single-entity trace element products can be used to meet individual patient needs when the multiple-element products are inappropriate (see Summary/A.S.P.E.N. Recommendations section for details of these proposed modifications).

Lecithin increases plasma free choline and decreases hepatic steatosis in long-term total parenteral nutrition patients

Plasma-free choline levels have previously been found below normal in patients receiving long term parenteral nutrition (TPN). In a group of 15 patients receiving home TPN who had low plasma free choline levels (6.3 +/- 0.8 mmol/L), we found 50% had hepatic steatosis. These patients were given oral lecithin or placebo in a double-blind randomized trial for 6 weeks. Lecithin supplementation led to an increase in plasma free choline of 53.4% +/- 15.4% at 2 weeks (P = 0.04), which continued at 6 weeks. The placebo group had no change in plasma-free choline at 2 weeks, but a significant decrease of 25.4% +/- 7.1% (P = 0.01) at 6 weeks. A significant and progressive decrease in hepatic fat was indicated by increased liver-spleen CT Hounsfield units at 2 and 6 weeks (7.5 +/- 1.7 units, P = 0.02; 13.8 +/- 3.5 units, P = 0.03) in the lecithin supplemental group. Nonsignificant changes were seen in the placebo group. It was concluded that hepatic steatosis in many patients receiving long term TPN is caused by plasma-free choline deficiency and may be reversed with lecithin supplementation. Choline is a conditionally essential nutrient in this population.

Nutritional support in patients with chronic liver disease

Malnutrition is highly prevalent among patients with chronic liver disease and is nearly universal among patients awaiting liver transplantation. Malnutrition in patients with cirrhosis leads to increased morbidity and mortality rates. Furthermore, patients who are severely malnourished before transplant surgery have a higher rate of complications and a decreased overall survival rate after liver transplantation. In light of the high incidence of malnutrition among patients with chronic liver disease and the complications that result from malnutrition in these patients, it is essential to assess the nutritional status of all patients with liver disease, and to initiate treatment as indicated. This review addresses the etiologies of malnutrition, methods used to assess nutritional status, and appropriate treatment strategies.