Met: PBL 1 (Coeliac Disease)

Question 1

What is haematocrit?

Answer 1

Ratio of erythrocytes to total blood volume

Question 2

What is mean corpuscular volume (MCV)?

Answer 2

The average volume of red blood cells

Question 3

What is ferritin?

Answer 3

Protein which stores iron in the tissues

Question 4

What is folate?

Answer 4

A B vitamin vital in the synthesis of fatty acids

Question 5

What is the role of alkaline phosphatase?

Answer 5

Dephosphorylates molecules

Question 6

What is the role of zonulin?

Answer 6

Acts to disassemble the actin filament associated with tight junctions; enteric bacteria and gliadin are the most potent stimulators

Question 7

What is a low haemoglobin level indicative of?

Answer 7

Anaemia

Question 8

What is a low haematocrit level indicative of?

Answer 8

Few red blood cells in the blood volume and therefore anaemia

Question 9

What are low ferritin levels indicative of?

Answer 9

Iron-deficiency as this protein is involved in the storage of iron

Question 10

What is a high MCV indicative of?

Answer 10

Macrocytic anaemia - implicated in folate or B12 deficiency anaemia

Question 11

Why may someone with coeliac disease have a low serum calcium level?

Answer 11

Unable to absorb enough calcium in the small intestine due to the absence of villi (blunting)

Question 12

What is the consequence of being unable to absorb enough calcium (as implicated in coeliac disease)?

Answer 12

Bones will be undergoing degradation to increase serum calcium levels, and if there is insufficient calcium to facilitate calcium deposition by osteoblasts then bone will be gradually degraded leading to weak bones as seen in Rickets/Osteomalacia

Question 13

What is the relationship between serum phosphate and serum calcium?

Answer 13

As one rises, the other one falls

Question 14

What is the role of serum phosphate?

Answer 14

Controls osteocytes and osteoblast’s apoptosis so is regulatory in the process of bone degradation

Question 15

What symptoms may low folate levels cause?

Answer 15

Fatigue, depression, pins and needles

Question 16

What may high levels of alkaline phosphatase indicate?

Answer 16

Bone disease as this enzyme is produced by bone in response

Question 17

Why may albumin levels bee checked in cases of anaemia?

Answer 17

Albumin is involved in carrying molecules in the blood, and this is to ensure that the liver is functioning effectively as it produces these molecules

Question 18

Why are total IgA antibody levels assessed in coeliac disease diagnosis?

Answer 18

Some individuals have an IgA deficiency and therefore have IgG antibodies to gliadin instead, and therefore by ensuring they have IgA antibodies before prevents a false-negative test

Question 19

What antibodies are present in coeliac disease?

Answer 19

Anti-endomysium and IgA anti-tTG antibodies

Question 20

What is osteomalacia?

Answer 20

Softening of the bones in adults due to defective bone mineralisation, commonly caused by insufficient calcium (Ca2+) absorption in the small intestine

Question 21

Why is a biopsy taken to confirm the diagnosis of coeliac disease?

Answer 21

To ensure that there is nothing else going on and that dietary changes will resolve the issue alone

Question 22

What would you see histologically in a jejunal biopsy of someone with coeliac disease?

Answer 22

Flattening/blunting of mucosal surface, many lymphocytes in lamina propria, sparse brush border and cuboidal rather than columnar epithelia, crypt hyperplasia

Question 23

Why may an individual not be diagnosed with coeliac disease until far later on in their life?

Answer 23

If they only have mild coeliac disease whereby their body can still absorb most of the nutrients so have no immediate side effects/symptoms, however, there are complications that arise from this untreated malabsorption such as osteomalacia

Question 24

Name and briefly describe the 3 structures making up the intestinal mucosa

Answer 24

Simple columnar epithelia - at the surface of the lumen with microvilli
Lamina propria - loose connective tissue (areolar CT)
Muscularis mucosae - layer of deep smooth muscle beneath

Question 25

What is the main gluten component that is destructive to the small intestinal mucosa?

Answer 25

Alpha-gliadin

Question 26

How would the duodenum appear in endoscopy in a coeliac patient?

Answer 26

There will be reduced duodenal folds

Question 27

What is the treatment of coeliac disease?

Answer 27

Gluten free diet; free from rye, barley and wheat

Question 28

What bacteria causes Whipple’s disease?

Answer 28

Trophyeryma whipplei

Question 29

What are the symptoms of Whipple’s disease?

Answer 29

Diarrhoea, steatorrhea, abdominal pain, joint pain

Question 30

How is Whipple’s disease diagnosed?

Answer 30

By duodenal biopsy which shows PAS positive macrophages in the lamina propria OR endoscopy would reveal pale, yellow, shaggy mucosa