Celiac disese | Anatomy2Medicine
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Celiac disese

    • Celiac disease
      • also known as celiac sprue or gluten-sensitive enteropathy (MCQ)
      • It is an immune-mediated enteropathy  (MCQ)
      • triggered by the ingestion of gluten-containing cereals, such as wheat, rye, or barley, in genetically predisposed individuals. (MCQ)
      • alcohol-soluble fraction of gluten, gliadin, contains most of the disease-producing components.

 

  • Pathophysiology :

 

        • Gluten is digested by luminal and brush-border enzymes into amino acids and peptides
        • α-gliadin peptide that is resistant to degradation by gastric, pancreatic, and small intestinal proteases
        • Some gliadin peptides induce epithelial cells to express IL-15 (MCQ)

 

  • IL-15 triggers activation and proliferation of CD8+ intraepithelial lymphocytes that are induced to express NKG2D, a natural killer cell marker. (MCQ)

 

        • These lymphocytes become cytotoxic and kill enterocytes with surface MIC-A, an HLA class I–like protein expressed in response to stress. (MCQ)
        • NKG2D is the receptor for MIC-A.

 

  • resulting epithelial damage may contribute to the process by which other gliadin peptides cross the epithelium to be deamidated by tissue transglutaminase. (MCQ)

 

        • Deamidated gliadin peptides are then able to interact with HLA-DQ2 or HLA-DQ8 on antigen-presenting cells and be presented to CD4+ T cells. (MCQ)
        • These T cells produce cytokines that contribute to tissue damage and the characteristic mucosal pathology.
      • almost all people with celiac disease carry the class II HLA-DQ2 or HLA-DQ8 allele. (MCQ)
      • Celiac disease show association with (MCQ)

 

  • type 1 diabetes, thyroiditis ,Sjögren syndrome
  • ataxia, autism, depression , some forms of epilepsy
  • IgA nephropathy, Down syndrome, and Turner syndrome.
  • Biopsy

 

        • Why the specimens are taken  from the second portion of the duodenum or proximal jejunum(MCQ)
          • they are exposed to the highest concentrations of dietary gluten
        • Biopsy is generally diagnostic in celiac disease
        • Histopathology (MCQ)

 

  • increased numbers of intraepithelial CD8+ T lymphocytes (intraepithelial lymphocytosis)
  • crypt hyperplasia (MCQ)
  • villous atrophy (MCQ)
  • This loss of mucosal and brush-border surface area probably accounts for the malabsorption.

 

        • increased numbers of plasma cells, mast cells, and eosinophils, especially within the upper part of the lamina propria. (MCQ)

 

  • Clinical Features

 

    • presents most commonly between the ages of 30 and 60
    • Symptomatic adult celiac disease is often associated with anemia, chronic diarrhea, bloating, or chronic fatigue.
    • celiac disease is detected two- to threefold more commonly in women, perhaps because monthly menstrual bleeding increases the demand for iron and vitamins and accentuates the effects of impaired absorption. (MCQ)
    • Pediatric celiac disease,

 

  • classic symptoms

 

          • disease typically begins between ages of 6 and 24 months, after introduction of gluten to the diet (MCQ)
          • includes irritability, abdominal distention, anorexia, chronic diarrhea, failure to thrive, weight loss, or muscle wasting

 

  • nonclassic symptoms

 

          • present at older ages
          • with complaints of abdominal pain, nausea, vomiting, bloating, or constipation.
        • Common extra-intestinal complaints include (MCQ)

 

  • arthritis or joint pain
  • seizure disorders
  • aphthous stomatitis
  • iron deficiency anemia
  • pubertal delay,
  • short stature
  • Dermatitis herpetiformis (MCQ)

 

      • characteristic itchy, blistering skin lesion
      • incidence of lymphocytic gastritis and lymphocytic colitis is also increased.

 

  • only treatment currently available is a gluten-free diet

 

    • long-term complications

 

  • anemia, female infertility
  • osteoporosis, and cancer

 

  • Noninvasive serologic tests
      • most sensitive tests are the presence of (MCQ)
        • IgA antibodies to tissue transglutaminase
        • IgA or IgG antibodies to deamidated gliadin.
      • Anti-endomysial antibodies (MCQ)
        • highly specific but less sensitive than other antibodies.
        • In cases with negative IgA tests, IgA deficiency, which is more common in celiac patients, should be ruled out.
        • If IgA deficiency is present, titers of IgG antibodies to tissue transglutaminase and deamidated gliadin should be measured.
  • The absence of HLA-DQ2 or HLA-DQ8 is useful for its high negative predictive value, but the presence of these alleles is not helpful in confirming the diagnosis.
  • Individuals with celiac disease have a higher than normal rate of malignancy
      • most common cancer is enteropathy-associated T-cell lymphoma (MCQ)
      • Small intestinal adenocarcinoma is also more frequent
  • When do you consider development of cancer in Whipples disease
      • when symptoms such as abdominal pain, diarrhea, and weight loss develop despite a strict gluten-free diet, cancer or refractory sprue, in which the response to a gluten-free diet is lost, must be considered

 

  • Tropical sprue
  • a malabsorption syndrome
  • Histologic changes of tropical sprue  vs celiac disease(MCQ)
    • total villous atrophy is uncommon
    • tropical sprue tends to involve the distal small bowel
    • folate or vitamin B12 deficiencies are more common in tropical sprue  
  • Malabsorption
    • Cause -overgrowth of aerobic enteric bacteria has been documented
    • broad-spectrum antibiotics usually effect rapid recovery.