Celiac Disease

Study guide:

Definition:  

A condition of autoimmunity & malabsorption precipitated by gluten (found in wheat, barely, & rye) in individuals with genetic predisposition.

  • Also known as celiac sprue or gluten sensitive enteropathy. 

 

Epidemiology:

  •  1% prevalence in whites (common)

  • Occurs at any age:

    • Early (almost 2 years)– Most common once gluten is introduced.  

    • Late (third to fourth decades)– Third decade is most commonly associated with pregnancy.

High-risk groups/ associations:

  • Individuals with first degree relatives suffering of celiac disease

  • Type 1 diabetes mellitus (most common).

  • Autoimmune diseases (1° biliary cirrhosis & hashimoto thyroiditis).

  • Turner's & Down syndromes.

  •  Associated with increased risk of malignancy (T-cell lymphoma). 

Pathogenesis:

Clinical manifestations:

  • Those with adequate surface area remaining:

    • Pallor due to anemia

    • Osteoporosis

    • Dermatitis herpetiformis: rash on the surfaces ofbuttocks & extensorsthat is itchy, blistering & burning. figure (1).

 

  • Those with significant mucosal involvement:​

    • Streatorrhea (or even watery diarrhea)

    • Weight loss

    • Failure to thrive (infants) 

    • Water-soluble & fat-soluble vitamin deficiencies:

      • Usually vitamin K deficiency -> tendency to bleed.

      • Cobalamin deficiency (in 10%)

      • Other systemic findings: delayed puberty, infertility, miscarriages, seizure, depression, and osteoporosis. 

Figure 1: Dermatitis Heptiformis.

Diagnosis:

  • Serology (diagnostic antibodies):

    • Anti–tissue transglutaminase IgA/IgG antibodies.  

    • By ELISA- IgA is the most important- 98% sensitivity & specificity- Excellent screening test; screening test of choice.  

    • Antiendomysial (EMA) IgA antibodies:

      •  By indirect immunofluorescence- 100% sensitivity & specificity (more specific than anti-tTG)

      • Excellent for screening; screening test of choice.

    • Anti-deaminated gliadin IgA/IgG antibodies - 80% sensitivity, 85% specificity- Moderately hood screening test.

  • Endoscopic biopsy:

  • Hallmark of diagnosis: confirmatory test.

  • Characteristics:

    • Blunt/flattened/absent villi in proximal intestine; duodenum & jejunum -> decreased mucosal absorption. Figure (2).

    • Crypt hyperplasia.

    • Increased intraepithelial lymphocytes (it could be the only abnormal fining in biopsy).

  • HLA genotyping:

    • Useful in exclusion: those who lack DQ2 or DQ8 gene 

Figure 2: Blunted villi.

Diagnosis:

  • Serology (diagnostic antibodies):

    • Anti–tissue transglutaminase IgA/IgG antibodies.  

    • By ELISA- IgA is the most important- 98% sensitivity & specificity- Excellent screening test; screening test of choice.  

    • Antiendomysial (EMA) IgA antibodies:

      •  By indirect immunofluorescence- 100% sensitivity & specificity (more specific than anti-tTG)

      • Excellent for screening; screening test of choice.

    • Anti-deaminated gliadin IgA/IgG antibodies - 80% sensitivity, 85% specificity- Moderately hood screening test.

  • Endoscopic biopsy:

  • Hallmark of diagnosis: confirmatory test.

  • Characteristics:

    • Blunt/flattened/absent villi in proximal intestine; duodenum & jejunum -> decreased mucosal absorption. Figure (2).

    • Crypt hyperplasia.

    • Increased intraepithelial lymphocytes (it could be the only abnormal fining in biopsy).

  • HLA genotyping:

    • Useful in exclusion: those who lack DQ2 or DQ8 gene 

Treatment:

  • Lifelong gluten-free diet (oats are tolerated the most though).

  • Supplements for nutritional deficiencies: folic acid, B12, & calcium.

  • Steroids in refractory cases. 

Prognosis: 

  • 90% happen to experience symptomatic improvement in two weeks when following a gluten-free diet. 

References:

  • Kumar, Parveen J, and Michael L Clark. Kumar & Clark's Clinical Medicine. Print.

  • Howland, Richard D et al. Pharmacology. Philadelphia: Lippincott Williams & Wilkins, 2006. Print.

  • Hldemo.ebscohost.com,. '| Diabetes Mellitus Type 2 In Adults'. N.p., 2015. Web. 5 Nov. 2015.

  • Haas, L. et al. 'National Standards For Diabetes Self-Management Education And Support'. Diabetes Care 37.Supplement_1 (2013): S144-S153. Web. 5 Nov. 2015.

  • Hall, Justin, and Azra Premji. Toronto Notes For Medical Students, Inc. © 2015. 2015. Print.

  • Agabegi, Steven S, Elizabeth D Agabegi, and Adam C Ring. Step-Up To Medicine. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2013. Print.

  • Fischer, Conrad. Master The Boards. Print.

  • Perez, Mayra, Lindsay K Botsford, and Winston Liaw. Déjà Review. New York: McGraw-Hill Medical, 2011. Print.

  • (DM), Diabetes. 'Diabetes Mellitus (DM) - Endocrine And Metabolic Disorders'. Merck Manuals Professional Edition. N.p., 2015. Web. 5 Nov. 2015.

  • Emedicine.medscape.com,. 'Type 1 Diabetes Mellitus: Practice Essentials, Background, Pathophysiology'. N.p., 2015. Web. 5 Nov. 2015.

  • Al-Rubeaan, Khalid et al. 'Epidemiology Of Abnormal Glucose Metabolism In A Country Facing Its Epidemic: SAUDI-DM Study'. Journal of Diabetes 7.5 (2014): 622-632. Web.

  • Aljabri, KhalidS, SamiaA Bokhari, and KhalidA Alqurashi. 'Prevalence Of Diabetes Mellitus In A Saudi Community'. Annals of Saudi Medicine 31.1 (2011): 19. Web.

  • ProProfs,. 'DIABETIC FOOT'. N.p., 2015. Web. 5 Nov. 2015. (Figure1). 

 

First author:    Lama Al Luhidan


Second author:  Roaa Amer


Reviewed by:    Abdullah AlAsaad
                           Haifa Al Issa
                           Husam Al Tahan


Format Editor:  Adel Yasky 

                          Bayan Alzomaili

Audio recording:


Read by: Thekra AlGholaiqa


Directed by: Rana Alzahrani


Audio production: Bayan Alzomaili

 

 

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