Protein-Losing Enteropathy Workup

Updated: Aug 30, 2023
  • Author: Naeem Aslam, MD; Chief Editor: Burt Cagir, MD, FACS  more...
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Laboratory Studies

The most prominent laboratory abnormality is a decrease in serum albumin and globulin.

A gastrointestinal disorder should be considered the cause of hypoalbuminemia after malnutrition, nephrotic syndrome, and chronic liver disease are excluded. The diagnostic workup can then be focused on gastrointestinal causes. [28]

The presence of alpha1-antitrypsin in the stool is an important diagnostic clue because it is not normally absorbed or secreted into the bowel. [29]  In patients with hyperacidity syndromes, this study is not accurate because of the degradation of alpha1-antitrypsin in an environment where the pH is less than 3. Measuring stool volume and stool alpha1-antitrypsin concentration shows the plasma clearance (PC) of alpha1-antitrypsin. [29] The plasma clearance of alpha1-antitrypsin can be used to monitor response to therapy.

Alpha 1-AT PC = ((stool volume) x (stool alpha 1-AT)) / (serum alpha-1 AT)

Erythrocyte sedimentation rate and serum total cholesterol levels have reported to be significantly elevated in patients with lupus-related protein-losing enteropathy.{ref29)

Viral serologies may be helpful.

In a prospective study that evaluated the immunologic characteristics of patients with protein-losing enteropathy (PLE) following Fontan procedures and those without postoperative PLE, patients with postoperative PLE all had markedly low CD4 T cell counts compared to the control subjects. [30] Both groups had mildly decreased CD8 T cells and normal to slightly elevated natural killer and B cells.

Also see Alpha1-Antitrypsin Deficiency.


Imaging Studies

Radionuclide-labeled serum albumin can be administered intravenously, and stool can be collected as a measure of protein exudation into the gastrointestinal tract. [31]

Computed tomography scanning may suggest lymphatic obstruction. This needs to be confirmed with lymphangiography.

Chest radiography, echocardiography, and radionuclide scanning of the heart detect cardiac disease.

Erosive or ulcerative conditions are diagnosed using radiographic contrast studies or, when possible, endoscopy and mucosal biopsies.

T2-weighted magnetic resonance imaging shows promise in the evaluation of lymphatic abnormalities in patients following functional single-ventricle palliative surgery. [19] Lymphatic anomalies might play a role in protein-losing enteropathy in this setting.


Other Tests

Primary gastrointestinal tract disease can be detected by endoscopy and biopsy, barium radiography, stools for ova and parasites, and culture. Primary gastrointestinal tract disease can be suggested by fecal occult blood.

Perform a hydrogen breath test for bacterial overgrowth in the small intestine.



Findings on endoscopic studies are usually normal unless primary gastrointestinal disease (eg, ulcerative colitis, Crohn disease, Ménétrier disease, viral mucosal ulcerations) is present. [32]


Histologic Findings

Mucosal abnormalities can be observed with inflammatory (colitis) and infectious (viral tuberculosis) causes and in lymphatic obstruction (lymphangiectasia). [33, 34, 35]