Enteral protein loss syndromeK90.4

Acquired or congenital pathologically increased protein loss due to the passage of plasma proteins into the intestinal lumen. Edema formation occurs as a result of hypoproteinemia.

In enteral protein loss syndrome, the balance between passive transfer of proteins into the intestinal lumen and the necessary reabsorption is disturbed. The protein loss (physiologically 1-4 g/day) can then no longer be compensated for by increasing synthesis. The consequence is hypoproteinemia with the most clinically recognizable tendency to edema. The laboratory diagnosis protein deficiency is a leading symptom of exudative enteropathy, provided that kidney diseases with proteinuria, a hepatic synthesis deficiency and malnutrition can be excluded.

Causes are:

• Enteral lymphatic congestion: e.g. due to obstruction of the lymphatic drainage in the intestinal wall with consecutive increase of pressure in the lymphatic channels and increased protein release into the intestine. Typical examples are intestinal lymphangiectases (primarily as a congenital disorder or secondarily as a consequence of obturating processes in the lymphatic system (tumor, inflammation, radiation).
• Mechanical obstruction of the lymph vessels.
• Increased pressure in the lymphatic vessels: In connection with congenital heart and vessel defects, enteral protein loss can occur as a complication, e.g. after mustard surgery for haemodynamic correction of transposition of the large vessels. Furthermore as a complication of a fontan operation (Johnson JN et al. 2012). Especially the diastolic pressure increase in the right atrium is suspected to be the cause of PLE because it reduces the venous return to the right heart. This leads to a backflow of blood into both vena cava.
• Mucous membrane diseases with consecutive protein exudation:
• Eosinophilic gastroenteritis (Talley NJ et al. 2001): the release of mediators from eosinophilic granulocytes causes increased permeability of the intestinal wall. Eosinophilic gastroenteritis can be associated with a typical food allergy.
• Ménétrier's disease (hypertrophy of the gastric mucosa with hyperplasia of the superficial epithelium "giant folded stomach"): The loss of protein through the gastric mucosa causes hypalbuminuria in 60-70% of patients and edema in 30%.
• Hypersecretory gastropathies with mucosal hypertrophies: e.g. in polyposis coli or in Cronkhite-Canada syndrome (D12.6) a generalized gastrointestinal polyposis which can lead to diarrhea and sometimes threatening malnutrition. Characteristic are ectodermal changes occurring within a short time with alopecia and loss of nails on fingers and toes (Dageförde J 2006).
• Whipple's disease: a slowly progressive multisystemic disease caused by the bacterium Tropheryma whippelii with lymphangiectasia of the intestinal wall and extensive exudative enteropathy.

Diarrhoea/steatorrhoea, weight loss, malabsorption syndrome

Hypoproteinemic edema (this occurs with a serum albumin < 2.5g/dl)

Additional symptoms in primary intestinal lymphangiectasia (M.Wladmann = congenital malformation of the lymph vessels) with pleural effusions, ascites, lymphocytopenia.

Albumin↓↓, Immunglobuline↓, alpha-1 antitrypsin in the chair ↑,

Determination of alpha1-antitrypsin clearance over a period of 3 days: Remark: α1-Antitrypsin is a protease inhibitor, which is excreted into the intestine analogous to albumin. α1-Antitrypsin is largely protected against bacterial decomposition due to its antiproteolytic properties.

Compared to the simple α1-antitrypsin determination in stool, the α1-antitrypsin clearance does not show any significant advantages which would justify the increased technical effort (stool collection period of several days, parallel determination of the α1-antitrypsin serum concentration).

Medical history, clinic, α1-Antitrypsin determination in stool (Dinari G et al. 1984)

Imaging procedures (X-ray, CT)

Endoscopic-bioptical methods with histological examination of the mucosa

Hypoproteinemic edema of renal or hepatic origin

Treatment of the underlying disease.

Nutritional therapy with the aim of regaining a balanced protein balance or compensating for the protein loss that has occurred (Kasper H 2004). Primary measure is the increase of the protein intake by a high-protein diet (1.2-2.0 g protein/kgkgKG/day). This should also be low in fat in order to reduce lymph leakage and thus protein loss by lowering the lymph pressure. Replacement of long-chain triglycerides with medium-chain triglycerides (MCT products, e.g. Ceres® margarine).

Note: MCT fats are completely removed via the portal vein. Therefore they have no influence on the lymph pressure. When using MCT fats over a long period of time, care must be taken to ensure a sufficient supply of essential fatty acids. This can be achieved by the additional administration of a fat rich in linoleic acid. Gfls. a medicinal supplementation of the fat-soluble vitamins(A, D, E, K) is also necessary.

In addition, restriction of the sodium intake: this counteracts the frequent formation of edema.

1. Allenspach K et al (2017) Hypovitaminosis D is associated with negative outcome in dogs with protein losing enteropathy: a retrospective study of 43 cases. BMC Vet Res 13:96.
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3. Dageförde J (2006) The CronkhiteCanada Syndrome. Med World 57: 284-287
4. Dinari G et al (1984) Random fecal a1-antitrypsin excretion in children with intestinal disorders. Am J Dis Child 138: 971-973
5. Johnson JN et al (2012) Protein-losing enteropathy and the Fontan operation. Nutr Clin Pract 27:375-384.
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8. Kasper H (2004) Nutritional medicine and dietetics. 10th ed., Urban and Fischer, Munich, S. 561
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10. Talley NJ et al (2001) Eosinophilic Gastroenteritis: a clinicopathological study of the disease of the mucosa, musclelayer and subserosal tissues. Good 31: 54-58