C - Coeliac Flashcards
typical presentation for coeliac
tiredness, muscle aches, weight loss
+/- GI symptoms
TATT bloods
FBC
U&Es
LFTs
Glucose
what type of anaemia is seen in coeliac
microcytic, hypochromic
3 causes of microcytic anaemia
iron deficiency
thalassaemia trait
anaemia of chronic disease
what things are you looking at on a blood film
cell types
number of each cell type
morphology of cells - ie shape
inclusions
colour (RBCs)
what does a poikilocyte RBC indicate
iron deficiency
what does anisopoikilocytosis
variation in shape and size
what does anisopoikilocytosis on blood film indicate
iron deficiency
what is basophilic stippling
aggregated ribosomal material of basophils
what causes basophilic stippling
beta thalassaemia trait
lead poisoning
alcoholism
sideroblastic anaemia
what does a hypersegmented neutrophil indicate
megaloblastic anaemia (impaired DNA synthesis)
what causes hypersegmented neutrophils / megaloblastic anaemia
b12 deficiency
folate deficiency
drugs
what do target cells indicate
iron deficiency
thalassaemia
hyposplenism
liver disease
what are target cells aka
codocytes
what is the SA:vol ratio like in target cells
high SA:vol ratio
what are howell jolly bodies
nuclear remnants in RBC
what do howell jolly bodies look like
dark dot in RBC
what do howell jolly bodies indicate
hyposplenism
causes of iron deficiency
blood loss
poor diet
malabsorption
combination of any of these
causes of megaloblastic change
b12 deficiency
folate deficiency
poor diet
pernicious anaemia
causes of hyposplenism
absent spleen
- trauma
- therapeutic
poor functioning spleen
- SLE
- IBD
- coeliac
- sickle cell
what is the biochem of coealic
low Ca
high ALP, normal LFTs
low vit D
high PTH
low Ca
high ALP, normal LFTs
low vit D
high PTH
what is this also the biochem of
secondary hyperparathyroidism (vitamin D deficiency)
why is ALP high in coeliac
secondary hyperparathyroidism due to low vit D causes chronic low Ca –> osteoclasts take Ca from bone to maintain blood levels –> chronic bone loss
DDx of coeliac
Crohns
stress
lesser:
menorrhagia
pancreatic disease
lymphoma
what blood levels would be different in crohns and coeliac
coealiac = low iron, b12, folate, fat, ca
crohns = low b12, bile salts
Ix for coeliac
CRP, ESR
anti TTg and anti e
upper GI endoscopy / duodenal biopsy
foecal calprotectin
what HLA do 90% of coeliacs have
HLA DQ2
how is pathogenicity of crohns and coeliac different
crohns is autoinflam
coeliac is autoimmune (therefore has auto ABs)
what is coeliac
abnormal immune response to gluten
what component of gluten causes the issue in coeliac
gliadin
how are gliadin peptides broken down
deaminated by TTG
what cell mediates the damage done in coeliac & how
gamma delta T cells expressing IEL
–> damaging duodenal epithelial cells
what type of ABs are anti TTG / anti e
IgA ABs
how specific are anti TTG
95%
what can cause a false negative with anti TTG ABs
if the patient is IgA deficient, the AB will be negative as they’re anti TTG ABs
when are the anti TTG ABs gone in coeliac
when gluten is avoided
if the ABs come back positive, do you still need OGD? why / why not?
YES - need a baseline and need to confirm diagnosis
gold standard diagnosis of coeliac
duodenal biopsy
what is the normal villi:crypt ratio
4:1
how many lymphocytes does a normal duodenal villus have per 100 epithelial cells
<20
where should the duodenal biopsy be taken from in the duodenum & why
2nd part of duodenum
- first contains Brunner’s gland which can distort the architecture
what is characteristic of coeliac on biopsy (3)
villous atrophy
crypt hyperplasia
>25 lymphocytes / 100 epithelial cells
what other diseases look like coeliac on biopsy
Sprue
enteropathy
Giardia
how can a pt have coeliac but have normal biopsy
if they’re currently on a gluten free diet
what can’t you eat if you’re on a gluten free diet
wheat
barely
rye
some oats
additives !!
what are the long term complications of coeliac
lymphoma !!
malabsorption
osteoporosis / osteomalacia
epilepsy
hyposplenism
cerebral calcification
why do coeliacs need ongoing monitoring
ensuring adherence to diet
what Ix are done for ongoing monitoring in coeliac
haem: FBC, iron, B12, folate, PT
biochem: Ca, PO43, LFT, U&E
anti TTG and anti e
DEXA of hip and spine every 3-5yrs
what can cause a persistent anti TTG AB+ in coeliac
not adherence to diet
LYMPHOMA
if coeliac is undiagnosed, what complications are they at risk of
low vit D, B12, folate, iron, K
++++ malignancy risk
2x mortality risk
associated conditions with coeliac
dermatitis herpetiformis
T1DM
AI thyroid disease
Down’s
all other AIDs
what is the prevelance of dermatitis herpetiformis in coeliac
100%
where is dermatitis herpetiformis
elbows
what % of coeliacs have T1DM
7%
when should you consider coeliac tests (4)
iron def anaemia
chronic diarrhoea
recurrent mouth ulcers
IBS
