Page 420 - Concise Pathology for Exam Preparation ( PDFDrive )

14 The Oral Cavity and Gastrointestinal Tract 405

• Oedema due to protein deficiency
• Dermatitis, mucositis and hyperkeratosis due to vitamin A, zinc, essential fatty acids and
niacin deficiency
• Osteopenia and tetany due to defective calcium absorption
• Amenorrhea, impotence and infertility from generalized malnutrition
• Hyperparathyroidism due to protracted calcium and vitamin deficiency

Q. Differentiate between celiac (nontropical) sprue and environmental
or tropical enteropathy.
Ans. Differences between celiac and tropical sprue are listed in Table 14.4.

TABLE 14.4. Differences between celiac and tropical sprue
Environmental or tropical enterop-
Features Celiac sprue athy (tropical sprue)
Other names Gluten-sensitive enteropathy, nontropical Post-infectious sprue; may occur in
sprue epidemic or endemic forms
Pathogenesis Immune-mediated disease due to sensitiv- Infectious disease. Occurs exclusively
ity to gluten and related proteins (water in patients living in or visiting the
insoluble gliadin) present in wheat, oat, tropics. No specific causal agent im-
barley and rye. No organism implicated. plicated. Enterotoxigenic bacterial
Gladden peptides induce secretion of IL (cyclospora and E. coli) overgrowth
15 which activates CD81 intraepithelial is found
lymphocytes. These lymphocytes ex-
press NKG2D, a natural killer cell
marker and receptor for MHC class I
polypeptide-related sequence (MIC-A).
Epithelial cells which express surface
MIC are recognized and attacked by
NKG2D expressing lymphocytes.
Genetic predisposition HLA (DQ2 and DQ8) association ac- None
counts for almost half of the genetic
component of celiac disease. The re-
maining genetic factors include poly-
morphisms of immune regulatory
genes like IL-2 and IL-21
Distribution Affects mainly the proximal part of small Affects the distal small bowel
intestine (higher gluten exposure than
distal part)
Associated clinical con- Dermatitis herpetiformis and neurological Frequent folate or vitamin B 12 defi-
ditions disorders ciency (due to involvement of distal
small bowel) leading to atypical en-
largement of nuclei of epithelial cells
(megaloblastic change)
Secondary malignancy Intestinal lymphoma, small intestinal ad- No such predisposition
enocarcinoma and oesophageal squa-
mous cell carcinoma
Treatment Gluten-restricted diet Broad-spectrum antibiotics

Q. Enumerate the morphologic features of celiac sprue.
Ans. Morphological Features
• Diffuse enteritis with atrophy or total loss of villi.
• Vacuolar degeneration of surface epithelium, loss of microvilli and increased number of
intraepithelial CD81 T lymphocytes.
• In an attempt to maintain mucosal thickness, crypts become hyperplastic, elongated
and tortuous and also show increased mitotic figures.

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