Week 7 Malabsorption Flashcards
Can try to fill this in if you have time but kinda fucked
Definition of coeliac disease
Chronic autoimmune-mediated gluten-sensitive enteropathy
Cause of coeliac disease
Caused by exposure to cereal prolamins in genetically susceptible individuals
To get it you have to be genetically susceptible AND have exposure.
Key takeaway for testing coeliac?
Many patients are asymptomatic, present with symptoms similar to IBS, or at the lower end of mal absorption.
So testing threshold should be very low, particularly in caucasians, those with autoimmune disease or FH of coeliac disease
Common deficiency in Coeliac?
Iron deficiency
Coeliac accounts for 5% of iron deficiency referals
How is coeliac diagnosed?
Requires ongoing gluten exposure
>2 slices of bread or 4 digestives/day for 4 weeks.
Serology:
TTG IgA now most widely used
98% sensitive; 90% specific
IgA deficiency
Endoscopy and duodenal biopsy:
4 x D2 biopsies and 2 x D1 biopsies
Histological diagnosis – modified Marsh criteria
Duodenal intraepithelial lymphocytosis (>25 IELs/100 enterocytes),
crypt hyperplasia, and villous atrophy
What is the key histological sign of coeliac disease?
- crypt hyperplasia
- villous atrophy
What does HLA testing tell you for coeliac?
Negative diagnosis only.
It doesn’t confirm coeliac because HLA gene is common.
However without HLA gene it is impossible to have coeliac
Coeliac presentation
GI:
* Chronic or intermittent diarrhoea, bloating, weight loss, fatigue, failure to thrive, lactose intolerance
* Any unexplained persistent GI symptoms
Extra-GI:
* Signs of specific micronutrient deficiencies
* Coeliac accounts for 5% of IDA referrals
* Neurological symptoms, particularly ataxia
* Dermatitis herpetiformis
* Raised liver enzymes
* Subfertility
* Metabolic bone disease
Coeliac treatment
Gluten free diet and annual review
What is refractory coeliac disease? WHat are the subtypes? How is it treated?
Refractory coeliac disease (RCD) is a rare complication of coeliac disease where symptoms persist or return despite a strict gluten-free diet.
RCD is diagnosed when other causes of ongoing symptoms are ruled out such as other GI problems.
It is split into subtypes RCD1 & RCD2 based on the characteristic and T cells involved
It is treated by steroid immunosupression
What has a worse prognosis RCD1 or RCD2?
RCD1 - 90% 5y survival rate
RCD2 - 50% 5y survival rate
What is Tropical Sprue?
An infectious enteropathy causing malabsorption.
Affects the whole small bowel and often follows a trip to the tropics.
Histology is similar to coeliac with villous atrophy however villous atrophy is often less severe than in coeliac and rarely flat.
What whipples disease?
Who is susceptible?
Whipple’s is a multisystem inflammatory condition caused by Tropheryma whipplei infection.
Middle aged men, farmers, HLA B27
As well as GI presents with cardiac, MSK and neuro symptoms.
Treatment with antibiotics
What is Giardiasis?
What is the treatment?
Giardia infection is an intestinal infection marked by stomach cramps, bloating, nausea and bouts of watery diarrhea.
Flagellated protozoan infection
Treatment with Metronidazole
What is SIBO?
Small intestine bacterial overgrowth.
Normally the small bowel has less bacteria than the colon and small intestine is gram -ve and colon gram +ve.
In SIBO this balance is lost
What causes SIBO?
Stasis:
* Blind loop/post-UGI Surgery
* Stricture
* Diverticulum
* Dysmotility -
Opioids, diabetes, systemic sclerosis, parkinson’s
Systemic imunodeficiency
Local mucosal disease
- Coeliac, Crohn’s, NSAIDs etc
PPI
PEI
What is a diagnosis of SIBO?
- Quantitative culture of jejunal fluid is the gold standard (> 10^3/mL is abnormal)
- Not widely available
- Glucose/Hydrogen breath test more practical
Rise of >20ppm hydrogen from baseline considered positive
False positive and negatives are common.
Treatment of SIBO?
Treatment
Rifaxamin 550mg TDS for 10-14 days
Diagnosis of malabsorption due to pancreatic exocrine insufficiency?
FE1
History - pacreatitis, surgery, type 1 diabetes etc.
Pancreatic imaging -> can confirm or at worse exclude malignancy
What is an FE1 test?
fecal elastase-1 test
non-invasive method used to assess the function of the pancreas, specifically its exocrine function
Management of pancreatic exocrine insufficiency?
PERT - pancreatic enzyme replacement therepy
Dietician
Smoking/ alcohol cessation
Take-home from malabsorption lecture
Without weight loss resist excessive investigations
With weight loss go ham
Easier to test causes than test for malabsorption directly
Seek a dietician
Rule out colorectal cancer
What is autoimmune enteropathy?
Autoimmune enteropathy (AIE) is a rare, chronic intestinal disorder where the immune system mistakenly attacks the lining of the small intestine, leading to severe diarrhea and malabsorption
