Protein losing enteropathy refers to any condition of the

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

(e.g. damage to the gut wall) that results in a net loss of

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

from the body.

Signs and symptoms

The signs/symptoms of protein losing enteropathy are consistent with diarrhea, fever, and general abdominal discomfort. Swelling of the legs due to peripheral edema can also occur, however, if the PLE is related to a systemic disease such as

congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

constrictive pericarditis Constrictive pericarditis is a medical condition characterized by a thickened, fibrotic pericardium, limiting the heart's ability to function normally. In many cases, the condition continues to be difficult to diagnose and therefore benefits from ...

, then the symptoms could be of the primary disease development.

Causes

The causes of protein-losing enteropathy can include GI conditions (among other causes), like the following:

Mechanism

The pathophysiology of protein losing enteropathy is a result of plasma proteins loss, which enters GI tract ( lumen). PLE is a complication of a disorder, be it

lymphatic Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to ...

obstruction or mucosal injury. In ''pediatric protein losing enteropathy'' there are several changes in

epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

cells causing PLE by augmenting the rate of flow of proteins (serum). Congenital molecular abnormalities, or dysfunctional lymphatic drainage might cause epithelial matrix changes.

Proteoglycans Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to whic ...

, which are glycosaminoglycan chains attached to protein, directly causes PLE, as well as, augments inflammatory

cytokines Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

. Children who have congenital

glycosylation Glycosylation is the reaction in which a carbohydrate (or ' glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not al ...

defects usually have protein losing enteropathy.

Diagnosis

The diagnosis of protein losing enteropathy is made by excluding other causes of protein loss.

Endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

can be used to localize the cause of the protein loss in the bowel. Different methods include faecal excretion of

alpha 1-antitrypsin Alpha-1 antitrypsin or α1-antitrypsin (A1AT, α1AT, A1A, or AAT) is a protein belonging to the serpin superfamily. It is encoded in humans by the ''SERPINA1'' gene. A protease inhibitor, it is also known as alpha1–proteinase inhibitor (A1PI) ...

which is a marker of protein losing enteropathy, as well as, viral serologies which may be useful to detect PLE.

Treatment

Treatment for protein losing enteropathy depends upon the underlying condition, according to Rychik, et al this could mean treatment of

hypoproteinemia Hypoproteinemia is a condition where there is an abnormally low level of protein in the blood. There are several causes that all result in edema once serum protein levels fall below a certain threshold. Causes # Nutritional hypoproteinemia is due ...

or of the

intestinal mucosa The gastrointestinal wall of the gastrointestinal tract is made up of four layers of specialised tissue. From the inner cavity of the gut (the lumen) outwards, these are: # Mucosa # Submucosa # Muscular layer # Serosa or adventitia The mucosa is ...

. For causes related to the heart, treatment for PLE after the '' Fontan operation'' treatment must be equal to the level of hypoproteinemia present. Therefore, it is useful to categorize patients based on their serum

albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins ...

levels, if less than normal (typically less than 3.5 g/dL) but greater than 2.5 g/dL, this can be seen as a mild form of protein losing enteropathy. Symptomatic management of edema with

furosemide Furosemide is a loop diuretic medication used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It may also be used for the treatment of high blood pressure. It can be taken by injection into a vein or by mouth ...

(and aldactone) can provide relief for the individual with mild hypoproteinemia.

In animals

Dogs can also suffer from PLE. Because the proteins are lost from the intestine, these dogs have low levels of albumin in the blood. Chronic enteropathy is one of the possible reasons for PLE and it has been shown in a study that hypoalbuminaemia is a risk factor for negative outcome and the prognosis is guarded for these dogs. Gastrointestinal lymphoma and intestinal lymphangiectasia are other diseases that can cause protein losing enteropathy in dogs The Breed Lundehunds seem to be predisposed for PLE.

References

External links

{{Medicine Gastrointestinal tract disorders