Efficacy and Mechanisms of GLN Dipeptide in the SICU

Critical Illness Clinical Trial

— GLND  

Official title:

Phase III Study on the Efficacy of Glutamine Dipeptide-Supplemented Parenteral Nutrition in Surgical ICU Patients

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00248638
• Other study ID #: IRB00024944
• Secondary ID: U01DK069322DK693
• Status: Completed
• Phase: Phase 3
• First received: November 3, 2005
• Last updated: January 18, 2018
• Start date: September 2006
• Est. completion date: December 2012

Study information

• Verified date: January 2018
• Source: Emory University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Relative glutamine (GLN) deficiency may contribute to morbidity and mortality in surgical intensive care unit (SICU) patients. During critical illness, GLN utilization by the immune system, gut mucosa and other tissues exceeds endogenous production and plasma GLN concentrations decrease, which may contribute to cellular dysfunction and increase nosocomial infection risk and mortality. Conventional GLN-free parenteral nutrition (PN) has a limited impact on SICU outcomes and does not repair the GLN deficit. Recent pilot data show that GLN dipeptide-supplemented PN decreases nosocomial infections and improves clinical outcomes in SICU patients. The process of benefit is poorly understood, but animal and human data suggest that GLN treatment correlates with a) up-regulation of cytoprotective molecules in blood and tissues [e.g, GSH, specific heat shock proteins (HSPs) and GLN]; and b) improved epithelial barrier defenses and immune cell number and function. Properties of L-GLN limit provision in solution, but the GLN dipeptide alanyl-GLN (AG) confers stability and solubility in PN (AG-PN). Investigators propose a multicenter, double-blind, randomized, controlled phase III trial based on our pilot data to test the hypothesis that AG-PN improves clinical outcomes in SICU patients requiring PN after cardiac, vascular or colonic operations. Subjects will receive either standard GLN-free PN or isocaloric, isonitrogenous, AG-PN until enteral feeds are established. Specific Aim 1 is to determine whether AG-PN decreases hospital mortality, nosocomial infection and other important indices of morbidity. Specific Aim 2 is to obtain novel, mechanistically relevant observational data in the Aim 1 subjects on whether AG-PN a) increases serial blood levels of GSH, HSP-70 and -27, and GLN; b) decreases the presence in serum of the bacterial products flagellin and LPS and the adaptive immune response to these mediators; and c) improves key indices of innate/adaptive immunity. This study is designed to delineate the clinical benefit of a major new nutrition support strategy in high-risk SICU patients.

Description:

Overview: Relative deficiency of glutamine (GLN) appears to contribute to morbidity and mortality in surgical intensive care unit (SICU) patients, but conventional nutrition support does not repair this deficit. GLN requirements increase during critical illness when utilization by the immune system, gut mucosa and other tissues exceeds endogenous production. GLN depletion under these conditions may contribute to hospital morbidity and mortality. Conventional parenteral nutrition (PN) does not contain GLN and thus does not prevent GLN depletion in catabolic patients. However, a pilot study and other reports strongly suggest that GLN-supplemented PN improves metabolic and clinical outcomes in critically ill patients. Underlying mechanisms for GLN action are poorly understood, but may involve systemic upregulation of the cytoprotective molecules glutathione (GSH), specific heat shock proteins (HSP) and GLN itself, improved gut barrier defenses, and improved innate and/or adaptive immune function. Properties of L-GLN limit provision in PN, but the dipeptide alanyl-glutamine (AG) confers stability and solubility in PN solutions. The pilot study demonstrated a marked decrease in nosocomial infection, improved indices of organ function, and a possible decrease in hospital mortality in SICU patients receiving AG-supplemented PN (AG-PN) versus standard, GLN-free PN (STD-PN). Investigators propose a multi-center, double-blind, controlled, Phase III trial, based on a pilot study, that will determine the effect of parenteral GLN on important clinical outcomes in patients requiring SICU care and PN after cardiac, vascular or colonic surgery. Investigators also propose to obtain needed hypothesis-generating, descriptive data from the Aim 1 study subjects to inform subsequent, truly mechanistic studies of GLN action in animal and human models of surgical critical illness. Study subjects will be randomized on an intent-to-treat basis to receive AG-PN or isonitrogenous, isocaloric STD-PN until enteral feeding is established.

Hypotheses:

1. SICU patients receiving PN supplemented with GLN dipeptide (AG-PN) will demonstrate improved clinical outcomes compared to patients receiving STD-PN.

2. Administration of AG-PN in the Aim 1 study subjects: a) increases serial blood levels of specific cytoprotective molecules and improves systemic redox status; b) is associated with decreased serum positivity for the bacterial products flagellin and lipopolysaccharide ( LPS) and the adaptive immune response to these mediators; and c) improves key indices of innate/adaptive immunity.

Specific Aims:

Aim 1: To perform a Phase III randomized controlled trial (RCT) to determine whether AG-PN decreases hospital mortality, nosocomial infections, and other indices of hospital morbidity versus STD-PN in SICU patients. The study will test whether AG-PN: decreases hospital mortality and the incidence of nosocomial infection (primary endpoints) in SICU patients after cardiac, vascular or colonic surgery. We will also determine whether AG-PN decreases total hospital infections, bloodstream infections (BSI), infections due to Staphylococcus aureus or fungal species, the number of days patients require mechanical ventilation, the SICU and total hospital length of stay and the 6-month mortality rate (secondary endpoints).

Aim 2: To determine in the Aim 1 study subjects whether AG-PN: a) increases systemic blood concentrations of the cytoprotective molecules GSH, HSP-70, HSP-27 and GLN and improves systemic GSH and cysteine redox status; b) is associated with decreased serum positivity for the bacterial products flagellin and LPS and titers of anti-flagellin and anti-LPS immunoglobulin M (IgM), immunoglobulin A (IgA) and immunoglobulin G (IgG); and c) improves key indices of innate/adaptive immune cell function.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 150
• Est. completion date: December 2012
• Est. primary completion date: December 2012
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 90 Years

Eligibility

Inclusion criteria: 1) A signed informed consent is in place on the patient's chart; 2) The patient is at least 18 but not more than 90 years of age at time of surgery; 3) The patient has a body mass index (BMI) < 40 kg/m2 prior to surgery; 4) The patient currently requires SICU care and is within 14 days postoperative from one of the following open (non-laparoscopic) surgical procedures: coronary artery bypass graft(CABG), cardiac valve, vascular (non-neurosurgical), or esophageal gastrointestinal resection of esophagus, stomach, small bowel, colon and/or rectum), or operation to identify the source of peritonitis when there is evidence of a bowel perforation (with or without bowel resection); 5) The patient will require central venous PN for 7+ subsequent days after entry on a clinical basis?; 6) There is central venous access for administration of the study PN; and 7) The patient's primary physician(s) will allow the investigative team to manage the study PN and enteral feedings during the current hospitalization.

Exclusion Criteria: 1) The patient is pregnant; 2) The patient has clinical sepsis [defined as unstable blood pressure despite pressor support AND mean arterial pressure (MAP) < 60 mm Hg on at least 3 consecutive readings within a 3-hour period during the 24 hours prior to study entry; 3) a) The patient has a current malignancy requiring surgery as the GLND qualifying operation OR b) the patient is currently receiving an active regimen of chemotherapy and/or radiotherapy to treat a previously diagnosed malignancy†; 4) The patient has a history of seizures or pre-existing seizure disorder; 5) The patient has a current encephalopathy*; 6) The patient has a known history of cirrhosis OR a serum total bilirubin level = 10.0 mg/dL); 7) The patient has a history of chronic renal failure requiring dialysis, or has significant renal dysfunction (defined as serum creatinine > 2.5 mg/dL and is not receiving continuous renal replacement therapy (CRRT) or the patient requires acute hemodialysis postoperatively; 8) The patient has a concomitant burn or trauma injury; 9) The patient has previously undergone an organ transplantation;10) the patient has a history of HIV/AIDS; 11) The patient has received any investigational drug within 60 days prior to study entry; 12) The patient has received enteral or parenteral enteral feedings enriched in arginine and/or glutamine within 30 days prior to study entry; and 13) The patient is unable or unwilling to participate in study procedures such as longitudinal blood draws and out patient follow-up visits, etc.

*Encephalopathy for GLND can be diagnosed only in non-chemically sedated patients by the primary critical care physicians or neurologist consultants and is defined as either a comatose state OR severe abnormalities diagnosed by electroencephalogram (EEG), OR if all of the following criteria are met: a) patient goes to sleep but is arousable to verbal and painful stimuli; does not open eyes spontaneously (decreased level of consciousness); b) patient exhibits severe confusion or complete disorientation when aroused (disorientation); c) patient exhibits severe lethargy or bizarre behavior (behavioral dysfunction); and d) patient exhibits inability to cooperate, asterixis, ataxia, clonus, decortication, decerebration, seizures, or rigidity (severe neuromuscular dysfunction).

† Patients with malignant metastasis and terminal untreatable carcinoma will be excluded as per the operational definition agreed upon by the Data Safety and Monitoring Board (DSMB).

? Please note that the patient should be in the SICU at the initial PN hang time.

Related Conditions & MeSH terms

• Critical Illness

Intervention

Drug:
• Glutamine dipeptide with 15% Clinisol
Subjects randomized to AG-PN will receive PN containing 0.5 g/kg/day of L alanyl L GLN (AG) dipeptide (Dipeptiven 20%; Fresenius-Kabi) and 1.0 g/kg/day of 15% Clinisol (Baxter Inc., Deerfield, IL) AA solution (total = 1.5 g/kg/day, with AG replacing 1/3 of Clinisol AA). The amount of GLN dipeptide administered each day will be determined by daily PN volume intake data.
• 15% Clinisol
Subjects randomized to STD-PN will receive 1.5 g/kg/day of 15% Clinisol. The amount of Clinisol administered each day will be determined by daily PN volume intake data.

Locations

Country	Name	City	State
United States	Emory University	Atlanta	Georgia
United States	University of Colorado Health Sciences Center	Denver	Colorado
United States	University Of Wisconsin Hospital	Madison	Wisconsin
United States	Vanderbilt University	Nashville	Tennessee
United States	The Miriam Hospital/Brown University	Providence	Rhode Island

Sponsors (2)

Lead Sponsor	Collaborator
Emory University	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Hospital Mortality Rate	Number of participants who died during hospitalization.	Current Hospitalization (Up to 6 Months)
Primary	Percentage of Patients Who do Not Develop Hospital Infections	Subjects remaining infection-free during the hospitalization.	Current Hospitalization (Up to 6 Months)
Secondary	Mean Glutathione Level	Glutathione (GSH) levels will be measured in µM (micro moles) from baseline to day 28. Higher levels indicate a higher GSH presence.	Baseline, Day 3, Day 7, Day 14, Day 21, Day 28
Secondary	Mean Heat Shock Proteins Level, HSP70	Levels of the heat shock protein,HSP70, will be measured in ng/mL from baseline to day 28. Higher levels indicate a higher protein presence.	Baseline, Day 3, Day 7, Day 14, Day 21, Day 28
Secondary	Mean Heat Shock Proteins Level, HSP27	Levels of the heat shock protein, HSP27, will be measured in pg/mL from baseline to day 28. Higher levels indicate a higher protein presence.	Baseline, Day 3, Day 7, Day 14, Day 21, Day 28