malabsorptive disorders of the intestine are categorized within this lecture into three categories: disorders related to insufficient digestive elements (such as lactase insufficiency), tropical sprue, celiac sprue. tropical sprue afflicts those who visit certain tropical countries and is thought to be related to infection by an unknown organism perhaps associated with an underlying nutritional deficiency. tropical sprue begins as foul, bulky stools characteristic of fat malabsorption, then progresses to systemic manifestations of malabsorption: weight loss, weakness, glossitis, stomatitis, cheilosis, hyperpigmentation, dry skin. a CBC might show megaloblastic anemia and a chem screen might show decreased levels of serum protein, calcium, phosphorous, cholesterol, prothrombin, HCl, but normal pancreatic function. decreased urine and serum levels in the D-xylose test is also used to diagnose tropical sprue.
gluten enteropathy is a general condition that involves a reactivity to gluten that afflicts up to 1/3 of the US population. of this subset, 5% have a more serious condition called celiacs which results in inflammation of the intestinal lining that leads to villous atrophy and malabsorption. traditionally a disease that afflicted young children, celiacs is now more commonly diagnosed in mid age adults- in particular those from western european, indian, south american, north african countries. there have been some hereditary factors identified such as certain allelles that are present in celiacs patients in the HLA-DQ2 and DQ1 genes, but for the most part the etiological mechanisms are unclear. celiacs patients might present with diarrhea / constipation, abdominal distention (in infants and children due to oncotic pressure changes resulting from low albumin levels), anemia / fatigue, hair loss, aphthous ulcers, dermatitis herpetiformis. lab tests of celiacs patients might show anemia of various types with an increased RDW, AST alkaline phosphatase with low albumin / plasma protein levels. other tests that can be performed are biopsy after gluten ingestion, and testing for IgA to gliadin, endomysial, tissue transglutaminase. two severe complications of celiacs that might arise are malignancy and osteoporosis.
the third major malabsorptive disorder that we learned about is lactase deficiency, the enzyme that digests lactose into glucose and galactose. this disorder is widespread and affects about 3/4 of the world's population, with a higher prevalence in native american, asian, and african american races. lactase deficiency can be congenital (very rare), primary (due to an inherent lack of production), or secondary (due to an acute illness or injury such as gastroenteritis or chemotherapy). it might result in a range of symptoms, from mild abdominal discomfort to severe diarrhea upon lactose ingestion. lactase deficiency is best diagnosed with the hydrogen breath test, which would measure abnormally high levels of hydrogen in the breath after ingestion of lactose. another method is simply to eliminate lactose from the diet and observe for change of symptoms.
questions
tropical sprue...
1. what is the etiology of tropical sprue?
2. what is the first stage of symptoms for tropical sprue?
3. what is the second stage of symptoms for tropical sprue?
4. what does a PE for tropical sprue patients reveal?
5. a CBC for tropical sprue patients might show...
6. what would stool analysis for a tropical sprue patient show?
7. what would a chem screen for a tropical sprue patient show?
8. what is the D-xylose absorption test?
gluten enteropathy and celiacs disease...
9. what is celiacs disease?
10. what is the difference between gluten enteropathy and celiacs?
11. why do babies with celiacs have big bellies?
12. what are the factors that increase susceptibility to a negative reaction with gliadin?
13. what are regions of the world associated with celiacs?
14. what percentage of americans have gluten enteropathy?
15. what percentage of americans have celiacs?
16. what are the symptoms of celiacs for infants?
17. what are the symptoms of celiacs for children?
18. what are the symptoms of celiacs for adults?
19. what percentage of patients with dermatitis herpetiformis has celiacs?
20. what will lab tests show for a celiacs patient?
21. what are the histological findings for a celiacs patient?
22. what is the definitive diagnosis for celiacs disease?
23. what are the IgA tests used to diagnose celiacs?
24. how specific is the diagnostic finding of tissue transglutaminase IgG?
25. what are some diseases associated with celiacs?
26. what are two important complications associated with celiacs?
lactase deficiency...
27. what is lactose intolerance?
28. how much of the world's population has lactase deficiency?
29. what are the different types of lactose intolerance?
30. what are two factors that can cause secondary lactose intolerance?
31. what are the signs and symptoms of lactase deficiency?
32. what is the lab test that can diagnose lactase deficiency?
33. what is another method for diagnosing lactase deficiency?
answers
1. idiopathic, or nutritional deficiency, infection.
2. bulky, pale, foul stools from fat malabsorption.
3. weight loss, flatulence, cramps, pallor, weakness, irritability.
4. signs of vitamin deficiency:
glossitis, stomatitis, cheilosis, hyperpigmentation, dry skin, abdominal distention, tenderness, edema, weight loss.
5. megaloblastic anemia.
6. fat malabsorption.
7. decreased:
serum protein
calcium
phosphorous
cholesterol
prothrombin
HCl
...and normal pancreatic function
[pcpcphp]
8. a test in which 25mg D-xylose is ingested orally, followed by 5 hour urine level measurement and 1 hour serum level measurement.
9. an immune related inflammation of the intestines related to gliadin which leads to loss of vili and malabsorption.
10. gluten enteropathy is a broader term than celiacs, referring to any condition that reacts to gliadin.
11. low albumin levels lead to changes in oncotic pressure which causes fluid to leak out into tissues.
12. some hereditary factors have been identified such as HLA-DQ2 and DQ1 genes, but precise mechanism is basically unknown.
13. western europe, india, south america, north africa,
14. 30%.
15. about 1/133.
16. diarrhea
abdominal distention
failure to thrive
anorexia, vomiting
psychomotor impairment
[diarrhea, distention, thrive, anorexia, impairement] [the infant's diarrhea impaired his intended to thrive on anorexia]
17. diarrhea / constipation
anemia
loss of appetite
secondary dentition
may have abdominal distention
[basically same as infants + secondary dentition?]
18. diarrhea / constipation
anemia / fatigue
dyspepsia / abdominal pain / weight loss
hair loss
aphthous ulcers
dermatitis herpetiformis
angular chelitis
cardiomyopathy
osteoporosis
weakness
[dad had a cow]
19. 75-90%.
20. anemia / increased RDW
increased AST, alkaline phosphatase
low albumin / plasma protein, cholesterol
21. villous atrophy is the characteristic finding.
22. ingest gluten and do a biospy.
23. anti gliadin IgA, anti endomysial IgA, anti tissue transglutaminase IgA
24. 100% specific.
25. type 1 diabetes, autoimmune thyroid disease
26. osteoporosis and malignancy (enteropathy associated t cell lymphoma)
27. a deficiency in lactase in the brush border resulting in an inability to digest lactose.
28. approximately 75%.
29. congenital (very rare), primary (due to inherent lactase production deficit), secondary (acute illness or injury)
30. acute gastroenteritis and chemotherapy.
31. ranges from minor abdominal discomfort to severe diarrhea in response to lactose, nausea
32. hydrogen breath test: measuring hydrogen breath levels after lactose ingestion.
33. eliminating lactose containing foods from the diet and observing change in symptoms.
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