Protein losing enteropathy: Difference between revisions

Jump to navigation Jump to search
Line 6: Line 6:


==Overview==  
==Overview==  
Protein losing enteropathy is the loss of plasma proteins from the gastrointestinal tract caused by an array of abnormalities
Protein losing [[enteropathy]] is the loss of plasma proteins from the gastrointestinal tract caused by an array of abnormalities


==Historical Perspective==
==Historical Perspective==
*[Disease name] was first discovered by [scientist name], a [nationality + occupation], in [year] during/following [event].
*[Disease name] was first discovered by [scientist name], a [nationality + occupation], in [year] during/following [event].
*In [year], [gene] mutations were first identified in the pathogenesis of [disease name].
*In [year], [gene] mutations were first identified in the pathogenesis of [disease name].
Line 14: Line 15:
   
   
==Classification==
==Classification==
*[Disease name] may be classified according to [classification method] into [number] subtypes/groups:
*[Disease name] may be classified according to [classification method] into [number] subtypes/groups:
:*[group1]
:*[group1]
:*[group2]
:*[group2]
:*[group3]
:*[group3]
*Other variants of [disease name] include [disease subtype 1], [disease subtype 2], and [disease subtype 3]
*Other variants of [disease name] include [disease subtype 1], [disease subtype 2], and [disease subtype 3]


==Pathophysiology==
==Pathophysiology==
Normally there is a balance between the synthesis and degradation of proteins maintained by a series of interconnected processes in the body. Any condition which disrupts the normal protein stasis where the loss of protein through the gastrointestinal tract exceeds the body’s ability to synthesize proteins failing to compensate for the loss leads to the development of a state of low serum protein called hypoproteinemia. <ref name="WaldmannWochner1969">{{cite journal|last1=Waldmann|first1=T.A.|last2=Wochner|first2=R.D.|last3=Strober|first3=W.|title=The role of the gastrointestinal tract in plasma protein metabolism|journal=The American Journal of Medicine|volume=46|issue=2|year=1969|pages=275–285|issn=00029343|doi=10.1016/0002-9343(69)90011-4}}</ref>
Normally there is a balance between the synthesis and degradation of [[proteins]] maintained by a series of interconnected processes in the body. Any condition which disrupts the normal protein [[stasis]] where the loss of protein through the [[gastrointestinal tract]] exceeds the body’s ability to synthesize proteins failing to compensate for the loss leads to the development of a state of low serum protein called [[hypoproteinemia]]. <ref name="WaldmannWochner1969">{{cite journal|last1=Waldmann|first1=T.A.|last2=Wochner|first2=R.D.|last3=Strober|first3=W.|title=The role of the gastrointestinal tract in plasma protein metabolism|journal=The American Journal of Medicine|volume=46|issue=2|year=1969|pages=275–285|issn=00029343|doi=10.1016/0002-9343(69)90011-4}}</ref>
*Primary gastrointestinal diseases such as inflammatory bowel disease and malignancies initiates a series of abnormal changes leading to the disruption of the protective mucosal layer of the gut resulting in inflammation, erosions and ulcerations of the normal mucosa leading to:
 
** Alteration in the mucosal lining of the gut.
*Primary [[gastrointestinal]] diseases such as [[inflammatory bowel disease]] and [[malignancies]] initiates a series of abnormal changes leading to the disruption of the protective [[mucosal layer]] of the gut resulting in [[inflammation]], [[erosions]] and [[ulcerations]] of the normal [[mucosa]] leading to:
** An increase in the permeability for the previously semi-permeable and non-permeable proteins, leading to excessive protein leakage through gastrointestinal tract.
**Alteration in the [[mucosal]] lining of the [[gut]].
** Decrease surface area for protein reabsorption leading to poor reabsorption.
**An increase in the permeability for the previously [[Semi-permeable membrane|semi-permeable]] and non-permeable [[proteins]], leading to excessive protein leakage through [[gastrointestinal tract]].
* Non-erosive gastrointestinal conditions such as connective tissue disorders and infectious diseases affecting the mucosa of the gastrointestinal tract causes the leakage of proteins into the lumen of gastrointestinal tract in a similar manner as erosive gastrointestinal diseases.
**Decrease surface area for protein reabsorption leading to poor reabsorption.
* Conditions leading to lymphatic obstruction such as lymphomas and other benign or malignant masses causes an increase in the pressure inside the lymphatic system which forces the lymph to leak out of the lymphatic vessels into the lumen of gastrointestinal tract leading to protein loss. <ref name="pmid30762910">{{cite journal| author=Craven MD, Washabau RJ| title=Comparative pathophysiology and management of protein-losing enteropathy. | journal=J Vet Intern Med | year= 2019 | volume= 33 | issue= 2 | pages= 383-402 | pmid=30762910 | doi=10.1111/jvim.15406 | pmc=6430879 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30762910  }} </ref>
*Non-erosive [[gastrointestinal]] conditions such as [[connective tissue disorders]] and [[infectious diseases]] affecting the [[mucosa]] of the [[gastrointestinal tract]] causes the leakage of [[proteins]] into the [[lumen]] of [[gastrointestinal tract]] in a similar manner as erosive [[gastrointestinal diseases]].
*Conditions leading to [[lymphatic obstruction]] such as [[lymphomas]] and other [[benign]] or [[malignant]] masses causes an increase in the pressure inside the [[lymphatic system]] which forces the [[lymph]] to leak out of the [[lymphatic vessels]] into the [[lumen]] of [[gastrointestinal tract]] leading to protein loss. <ref name="pmid30762910">{{cite journal| author=Craven MD, Washabau RJ| title=Comparative pathophysiology and management of protein-losing enteropathy. | journal=J Vet Intern Med | year= 2019 | volume= 33 | issue= 2 | pages= 383-402 | pmid=30762910 | doi=10.1111/jvim.15406 | pmc=6430879 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30762910  }} </ref>


==Causes==
==Causes==
Most cases of protein losing enteropathy are caused as a result of:
Most cases of [[protein]] losing [[enteropathy]] are caused as a result of:


#Primary [[gastrointestinal]] disorders
#Primary [[gastrointestinal]] disorders
#[[Lymphatic obstruction]]
#[[Lymphatic obstruction]]


=== Primary Gastrointestinal Diseases ===
===Primary Gastrointestinal Diseases===
<ref name="CravenWashabau2019">{{cite journal|last1=Craven|first1=Melanie D.|last2=Washabau|first2=Robert J.|title=Comparative pathophysiology and management of protein‐losing enteropathy|journal=Journal of Veterinary Internal Medicine|volume=33|issue=2|year=2019|pages=383–402|issn=0891-6640|doi=10.1111/jvim.15406}}</ref>
<ref name="CravenWashabau2019">{{cite journal|last1=Craven|first1=Melanie D.|last2=Washabau|first2=Robert J.|title=Comparative pathophysiology and management of protein‐losing enteropathy|journal=Journal of Veterinary Internal Medicine|volume=33|issue=2|year=2019|pages=383–402|issn=0891-6640|doi=10.1111/jvim.15406}}</ref>


=====Mucosal Erosions/Ulcerations=====
=====Mucosal Erosions/Ulcerations=====
Primary [[gastrointestinal]] diseases causing erosion or [[ulceration]] of the [[mucosa]] of the [[gut]] leading to fecal loss of proteins such as:<ref name="pmid30408010">{{cite journal| author=Akkelle BS, Tutar E, Sengul OK, Celikel CA, Ertem D| title=A Rare Complication of Giardiasis in Children: Protein-losing Enteropathy. | journal=Pediatr Infect Dis J | year= 2018 | volume= 37 | issue= 12 | pages= e345-e347 | pmid=30408010 | doi=10.1097/INF.0000000000002025 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30408010  }}</ref><ref name="pmid30834767">{{cite journal| author=Zubiaga Toro L, Ruiz-Tovar J, Castro MJ, Ortiz de Solórzano FJ, Luque de León E, Jiménez JM | display-authors=etal| title=Whipple disease after bariatric surgery: from malabsorption to malnutrition status. | journal=Nutr Hosp | year= 2019 | volume= 36 | issue= 1 | pages= 238-241 | pmid=30834767 | doi=10.20960/nh.02258 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30834767  }}</ref>
Primary [[gastrointestinal]] diseases causing erosion or [[ulceration]] of the [[mucosa]] of the [[gut]] leading to [[fecal]] loss of [[proteins]] such as:<ref name="pmid30408010">{{cite journal| author=Akkelle BS, Tutar E, Sengul OK, Celikel CA, Ertem D| title=A Rare Complication of Giardiasis in Children: Protein-losing Enteropathy. | journal=Pediatr Infect Dis J | year= 2018 | volume= 37 | issue= 12 | pages= e345-e347 | pmid=30408010 | doi=10.1097/INF.0000000000002025 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30408010  }}</ref><ref name="pmid30834767">{{cite journal| author=Zubiaga Toro L, Ruiz-Tovar J, Castro MJ, Ortiz de Solórzano FJ, Luque de León E, Jiménez JM | display-authors=etal| title=Whipple disease after bariatric surgery: from malabsorption to malnutrition status. | journal=Nutr Hosp | year= 2019 | volume= 36 | issue= 1 | pages= 238-241 | pmid=30834767 | doi=10.20960/nh.02258 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30834767  }}</ref>


*[[Inflammatory bowel diseases]] ([[Crohn disease]], [[Ulcerative colitis]])
*[[Inflammatory bowel diseases]] ([[Crohn disease]], [[Ulcerative colitis]])
*[[Malignancies]] involving the gut [[mucosa]]
*[[Malignancies]] involving the [[gut]] [[mucosa]]
*Graft vs. host disease
*[[Graft vs. host disease]]
*[[Esophageal]] and [[gastric]] erosions or [[Ulceration|ulcerations]]
*[[Esophageal]] and [[gastric]] erosions or [[Ulceration|ulcerations]]
*[[Carcinoid syndrome]]
*[[Carcinoid syndrome]]
*Bacterial infection with [[Clostridium difficile]] causing [[pseudomembranous colitis]]
*[[Bacterial infection]] with [[Clostridium difficile]] causing [[pseudomembranous colitis]]
*[[Parasitic]] infection with [[Giardia]]
*[[Parasitic]] infection with [[Giardia]]


Line 58: Line 63:


===Lymphatic Obstruction===
===Lymphatic Obstruction===
Conditions responsible for causing [[lymphatic]] obstruction leading to the leakage of [[lymph]] into the lumen of gut such as:
Conditions responsible for causing [[lymphatic]] obstruction leading to the leakage of [[lymph]] into the [[lumen]] of [[gut]] such as:


*[[Lymphoma]]
*[[Lymphoma]]
*[[Congenital]] or acquired lymphatic diseases
*[[Congenital]] or acquired [[lymphatic diseases]]
*Lymphatic [[filariasis]]
*Lymphatic [[filariasis]]
*[[Sarcoidosis]]
*[[Sarcoidosis]]
*Cardiovascular diseases: [[Congestive heart failure]], Restrictive [[pericarditis]]
*Cardiovascular diseases: [[Congestive heart failure]], Restrictive [[pericarditis]]
*Intestinal [[Tuberculosis]]
*[[Intestinal]] [[Tuberculosis]]
*[[Fortan surgical procedure]]
*[[Fortan surgical procedure]]
*[[Cirrhosis]] with [[portal hypertension]]
*[[Cirrhosis]] with [[portal hypertension]]
Line 126: Line 131:
Following the detection of abnormal amounts of alpha-1 antitrypsin in the stool, the following tests can be performed to detect the specific etiology for the protein loss into the gastrointestinal lumen.<ref name="LevittLevitt2017">{{cite journal|last1=Levitt|first1=David|last2=Levitt|first2=Michael|title=Protein losing enteropathy: comprehensive review of the mechanistic association with clinical and subclinical disease states|journal=Clinical and Experimental Gastroenterology|volume=Volume 10|year=2017|pages=147–168|issn=1178-7023|doi=10.2147/CEG.S136803}}</ref>
Following the detection of abnormal amounts of alpha-1 antitrypsin in the stool, the following tests can be performed to detect the specific etiology for the protein loss into the gastrointestinal lumen.<ref name="LevittLevitt2017">{{cite journal|last1=Levitt|first1=David|last2=Levitt|first2=Michael|title=Protein losing enteropathy: comprehensive review of the mechanistic association with clinical and subclinical disease states|journal=Clinical and Experimental Gastroenterology|volume=Volume 10|year=2017|pages=147–168|issn=1178-7023|doi=10.2147/CEG.S136803}}</ref>


*Administration of [[technetium-99]] labeled macromolecules such as [[albumin]]. Imaging is required to localize the primary site of protein leakage with no requirement for fecal collection. [[Scintigraphy]] is becoming popular in the diagnosis and localization of the site of protein leakage.  
*Administration of [[technetium-99]] labeled [[macromolecules]] such as [[albumin]]. [[Imaging]] is required to localize the primary site of [[protein]] leakage with no requirement for fecal collection. [[Scintigraphy]] is becoming popular in the diagnosis and localization of the site of protein leakage.  


*For the diagnosis of [[lymphatic obstruction]], computed tomography, lymphangiography or magnetic resonance imaging can be used.
*For the diagnosis of [[lymphatic obstruction]], [[computed tomography]], [[lymphangiography]] or [[magnetic resonance imaging]] can be used.


* [[Radiographic]] contrast studies and [[endoscopy]] can be performed to evaluate the [[ulcerative]] or erosive gastrointestinal causes of the protein loss.
* [[Radiographic]] contrast studies and [[endoscopy]] can be performed to evaluate the [[ulcerative]] or erosive [[gastrointestinal]] causes of the protein loss.


*For detecting cardiac diseases causing loss of protein, [[echocardiography]] or [[radionuclide]] scanning of the heart can be performed.
*For detecting [[cardiac]] diseases causing loss of protein, [[echocardiography]] or [[radionuclide]] scanning of the heart can be performed.


==='''Other tests:'''===
==='''Other tests:'''===
Line 138: Line 143:
*All patients should undergo basic laboratory tests such as complete blood test, [[Liver function tests|liver]] and [[renal function tests]].
*All patients should undergo basic laboratory tests such as complete blood test, [[Liver function tests|liver]] and [[renal function tests]].


*Work up for autoimmune diseases such as [[systemic lupus erythematosus]] should be ordered if there is a suspicion of [[connective tissue disorder]] causing protein loss in the gastrointestinal tract.
*Work up for [[autoimmune diseases]] such as [[systemic lupus erythematosus]] should be ordered if there is a suspicion of [[connective tissue disorder]] causing protein loss in the [[gastrointestinal tract]].


*[[Biopsy]] samples of the [[mucosa]] and stool cultures for [[ova]] and [[parasites]] should be performed if there is a suspicion of ulcerative or erosive gastrointestinal disease and parasitic infection, respectively.
*[[Biopsy]] samples of the [[mucosa]] and stool cultures for [[ova]] and [[parasites]] should be performed if there is a suspicion of ulcerative or erosive [[Gastrointestinal diseases|gastrointestinal disease]] and [[parasitic infection]], respectively.


==Treatment==
==Treatment==

Revision as of 07:12, 13 February 2021

WikiDoc Resources for Protein losing enteropathy

Articles

Most recent articles on Protein losing enteropathy

Most cited articles on Protein losing enteropathy

Review articles on Protein losing enteropathy

Articles on Protein losing enteropathy in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Protein losing enteropathy

Images of Protein losing enteropathy

Photos of Protein losing enteropathy

Podcasts & MP3s on Protein losing enteropathy

Videos on Protein losing enteropathy

Evidence Based Medicine

Cochrane Collaboration on Protein losing enteropathy

Bandolier on Protein losing enteropathy

TRIP on Protein losing enteropathy

Clinical Trials

Ongoing Trials on Protein losing enteropathy at Clinical Trials.gov

Trial results on Protein losing enteropathy

Clinical Trials on Protein losing enteropathy at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Protein losing enteropathy

NICE Guidance on Protein losing enteropathy

NHS PRODIGY Guidance

FDA on Protein losing enteropathy

CDC on Protein losing enteropathy

Books

Books on Protein losing enteropathy

News

Protein losing enteropathy in the news

Be alerted to news on Protein losing enteropathy

News trends on Protein losing enteropathy

Commentary

Blogs on Protein losing enteropathy

Definitions

Definitions of Protein losing enteropathy

Patient Resources / Community

Patient resources on Protein losing enteropathy

Discussion groups on Protein losing enteropathy

Patient Handouts on Protein losing enteropathy

Directions to Hospitals Treating Protein losing enteropathy

Risk calculators and risk factors for Protein losing enteropathy

Healthcare Provider Resources

Symptoms of Protein losing enteropathy

Causes & Risk Factors for Protein losing enteropathy

Diagnostic studies for Protein losing enteropathy

Treatment of Protein losing enteropathy

Continuing Medical Education (CME)

CME Programs on Protein losing enteropathy

International

Protein losing enteropathy en Espanol

Protein losing enteropathy en Francais

Business

Protein losing enteropathy in the Marketplace

Patents on Protein losing enteropathy

Experimental / Informatics

List of terms related to Protein losing enteropathy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

Synonyms and keywords: Protein loss, protein deficiency, GI protein loss, gastrointestinal protein loss, protein-losing gastroenteropathy, protein-losing gastroenteropathy, gastroenteropathy, gastric protein loss, helicobacter pylori, H pylori, giant hypertrophic gastropathy, menetrier disease, ménétrier, disease, loss of plasma proteins from the gastrointestinal tract, excessive leakage of plasma proteins into the lumen of the gastrointestinal tract, lymphatic obstruction, mucosal disease with erosions, ulcerations, swelling of the legs, peripheral edema, decreased plasma oncotic pressure

Overview

Protein losing enteropathy is the loss of plasma proteins from the gastrointestinal tract caused by an array of abnormalities

Historical Perspective

  • [Disease name] was first discovered by [scientist name], a [nationality + occupation], in [year] during/following [event].
  • In [year], [gene] mutations were first identified in the pathogenesis of [disease name].
  • In [year], the first [discovery] was developed by [scientist] to treat/diagnose [disease name].

Classification

  • [Disease name] may be classified according to [classification method] into [number] subtypes/groups:
  • [group1]
  • [group2]
  • [group3]
  • Other variants of [disease name] include [disease subtype 1], [disease subtype 2], and [disease subtype 3]

Pathophysiology

Normally there is a balance between the synthesis and degradation of proteins maintained by a series of interconnected processes in the body. Any condition which disrupts the normal protein stasis where the loss of protein through the gastrointestinal tract exceeds the body’s ability to synthesize proteins failing to compensate for the loss leads to the development of a state of low serum protein called hypoproteinemia. [1]

Causes

Most cases of protein losing enteropathy are caused as a result of:

  1. Primary gastrointestinal disorders
  2. Lymphatic obstruction

Primary Gastrointestinal Diseases

[3]

Mucosal Erosions/Ulcerations

Primary gastrointestinal diseases causing erosion or ulceration of the mucosa of the gut leading to fecal loss of proteins such as:[4][5]

Non-Erosive/Ulcerative Mucosal involvement

Lymphatic Obstruction

Conditions responsible for causing lymphatic obstruction leading to the leakage of lymph into the lumen of gut such as:

Complete Differential Diagnosis Of Underlying Causes

Diagnosis

As hypoproteinemia is the key factor in evaluating a patient for protein losing enteropathy, other common causes of hypoproteinemia such as nephrotic syndrome, impaired protein synthesis due to chronic liver disease and malnutrition must be excluded first.[10]

Laboratory Studies

As the most prominent laboratory finding is a decrease in serum concentration of albumin and globulin, the diagnostic work up protein losing enteropathy consist of quantitative measurements of Alpha-1 antitrypsin or 51Cr-albumin.[11]

  • Alpha-1 antitrypsin (A1AT) used as an endogenous marker is a sensitive and inexpensive laboratory test performed to diagnose protein losing enteropathy and has become the current standard for quantitating protein losing enteropathy.[12] Measurement of fecal volume and fecal loss of alpha-1 antitrypsin depicts the plasma concentration of alpha-1 antitrypsin as;

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

Gastrointestinal loss of alpha-1 antitrypsin is measured in feces and a clearance greater than 27mL/day is considered diagnostic for protein losing enteropathy.[13]

  • 51Cr-labeled albumin can also be measured followed by stool collection to determine the amount of protein loss into the gastrointestinal tract.

Imaging Studies

Following the detection of abnormal amounts of alpha-1 antitrypsin in the stool, the following tests can be performed to detect the specific etiology for the protein loss into the gastrointestinal lumen.[11]

Other tests:

Treatment

Treatment depends upon the underlying condition.

References

  1. Waldmann, T.A.; Wochner, R.D.; Strober, W. (1969). "The role of the gastrointestinal tract in plasma protein metabolism". The American Journal of Medicine. 46 (2): 275–285. doi:10.1016/0002-9343(69)90011-4. ISSN 0002-9343.
  2. Craven MD, Washabau RJ (2019). "Comparative pathophysiology and management of protein-losing enteropathy". J Vet Intern Med. 33 (2): 383–402. doi:10.1111/jvim.15406. PMC 6430879. PMID 30762910.
  3. Craven, Melanie D.; Washabau, Robert J. (2019). "Comparative pathophysiology and management of protein‐losing enteropathy". Journal of Veterinary Internal Medicine. 33 (2): 383–402. doi:10.1111/jvim.15406. ISSN 0891-6640.
  4. Akkelle BS, Tutar E, Sengul OK, Celikel CA, Ertem D (2018). "A Rare Complication of Giardiasis in Children: Protein-losing Enteropathy". Pediatr Infect Dis J. 37 (12): e345–e347. doi:10.1097/INF.0000000000002025. PMID 30408010.
  5. Zubiaga Toro L, Ruiz-Tovar J, Castro MJ, Ortiz de Solórzano FJ, Luque de León E, Jiménez JM; et al. (2019). "Whipple disease after bariatric surgery: from malabsorption to malnutrition status". Nutr Hosp. 36 (1): 238–241. doi:10.20960/nh.02258. PMID 30834767.
  6. Venkatesh, Balasubramanian; Gough, Jenny; Ralston, David R.; Muller, Michael; Pegg, Stuart (2004). "Protein losing enteropathy in critically ill adult patients with burns: a preliminary report". Intensive Care Medicine. 30 (1): 162–166. doi:10.1007/s00134-003-2050-2. ISSN 0342-4642.
  7. Furfaro F, Bezzio C, Maconi G (2015). "Protein-losing enteropathy in inflammatory bowel diseases". Minerva Gastroenterol Dietol. 61 (4): 261–5. PMID 26446687.
  8. Amiot A (2015). "[Protein-losing enteropathy]". Rev Med Interne. 36 (7): 467–73. doi:10.1016/j.revmed.2014.12.001. PMID 25618488.
  9. "StatPearls". 2020. PMID 31194423.
  10. Umar, Sarah B; DiBaise, John K (2010). "Protein-Losing Enteropathy: Case Illustrations and Clinical Review". American Journal of Gastroenterology. 105 (1): 43–49. doi:10.1038/ajg.2009.561. ISSN 0002-9270.
  11. 11.0 11.1 Levitt, David; Levitt, Michael (2017). "Protein losing enteropathy: comprehensive review of the mechanistic association with clinical and subclinical disease states". Clinical and Experimental Gastroenterology. Volume 10: 147–168. doi:10.2147/CEG.S136803. ISSN 1178-7023.
  12. Karbach U, Ewe K (1989). "Enteric protein loss in various gastrointestinal diseases determined by intestinal alpha 1-antitrypsin clearance". Z Gastroenterol. 27 (7): 362–5. PMID 2475983.
  13. Florent C, L'Hirondel C, Desmazures C, Aymes C, Bernier JJ (1981). "Intestinal clearance of alpha 1-antitrypsin. A sensitive method for the detection of protein-losing enteropathy". Gastroenterology. 81 (4): 777–80. PMID 6973500.