From the Guidelines
Protein-losing enteropathy (protein enteropathy) is a condition characterized by excessive loss of protein through the gastrointestinal tract, often seen in patients with complex cardiac physiology, such as those with Fontan repairs, and can manifest as hypoalbuminemia, hepatic dysfunction, and exercise limitation. This condition is thought to be related to the obligatory elevation in central venous pressure and reduced cardiac output, leading to damage or inflammation of the intestinal lining, allowing proteins to leak from the bloodstream into the intestinal lumen where they are excreted 1. Key features of protein-losing enteropathy include:
- Excessive protein loss through the gastrointestinal tract
- Hypoalbuminemia
- Hepatic dysfunction
- Exercise limitation
- Lower extremity venous congestion Management of protein-losing enteropathy may involve medical therapies such as:
- Aldosterone antagonists
- Subcutaneous unfractionated heparin to stabilize the proteoglycan layer of the gut
- PAH therapies, including endothelin antagonists like bosentan, which has shown improved exercise capacity in patients with Fontan repairs 1
- Corticosteroids, specifically budesonide, for patients with hypoalbuminemia, which may have fewer systemic effects than other oral steroids, but requires close monitoring for signs of hypercortisolism 1
- Octreotide, which has limited anecdotal experience, but may be considered in certain cases 1 A combination of these therapies may be applied to achieve improved outcomes, as collective strategies have produced better results compared to historic controls 1. Regular monitoring of serum protein levels, particularly albumin, is essential to assess treatment effectiveness and disease progression. Prognosis varies widely depending on the underlying cause, with some cases resolving completely with treatment while others may require ongoing management.
From the Research
Definition and Causes of Protein-Losing Enteropathy
- Protein-losing enteropathy (PLE) is a rare syndrome of gastrointestinal protein loss that may complicate a variety of diseases 2.
- The primary causes of PLE can be divided into erosive gastrointestinal disorders, nonerosive gastrointestinal disorders, and disorders involving increased central venous pressure or mesenteric lymphatic obstruction 2.
- PLE describes a syndrome of excessive protein loss into the gastrointestinal tract, which may be due to a wide variety of etiologies 3.
- The disorders causing PLE can be divided into those due to protein loss from intestinal lymphatics, like primary intestinal lymphangiectasia or congenital heart disease, and those with protein loss due to an inflamed or abnormal mucosal surface 4.
Diagnosis of Protein-Losing Enteropathy
- The diagnosis of PLE should be considered in patients with hypoproteinemia after other causes, such as malnutrition, proteinuria, and impaired protein synthesis due to cirrhosis, have been excluded 2.
- The diagnosis is confirmed by increased fecal concentrations of alpha-1-antitrypsin 4, 5.
- The determination of fecal alpha-1 antitrypsin clearance is used to diagnose PLE 2, 6.
Treatment and Management of Protein-Losing Enteropathy
- Treatment of PLE targets the underlying disease but also includes dietary modification, supportive care, and maintenance of nutritional status 2.
- Medical nutrition therapy focused on restricting enteral long-chain triglycerides and thus intestinal chyle production is an integral component of treatment for children with PLE associated with lymphangiectasia 3.
- Supplemental calories may be provided with medium-chain triglycerides (MCT) in patients with ongoing active PLE or those who are on a fat-restricted diet 3.
- Treatment of PLE consists of nutrition state maintenance by using a high protein diet with supplement of fat-soluble vitamins, and in patients with lymphangiectasia, a low fat with medium chain triglycerides (MCT) diet should be prescribed 4.