Gastroenterology Flashcards
Coeliac disease Primary biliary cholangitis & Primary sclerosing cholangitis
What are the Dukes Staging System for Bowel Cancer?
Dukes A – tumour confined to bowel wall
Dukes B – tumour has gone through wall but not into nodes
Dukes C – tumour involving regional nodes
Dukes D – distant metastases are present
Dukes stage histologically affects prognosis – i.e. 90% alive at 5 years Dukes A, reducing to 10% for Dukes D.
Definition - Coeliac disease
Autoimmune condition - immune reaction caused by the exposure to gluten.
Leads to inflammation of the D2 small bowel (jejunum)
Where is the inflammation of the coeliac disease?
Jejunum - epithelial cells of intestine. Atrophy of intestinal villi and hypertrophy of crypt cells
When does coeliac normally present?
Early chlidhood but can present at any stage
What are the 3 main autoantibodies involved? (qhat is 3rd)
Anti-TTG & Anti- EMA (gliadin) & endomysium
Class: IgA.
Relate to disease activity - rise and fall depending on how active disease is.
(Deaminated gliadin peptide - less commonly found)
What is the main complication of coeliac?
think: which cells affected
Atrophy of intestinal villi
Effect: malabsorption of nutrients
How can coeliac patients present?
Low threshold needed for suspected cases. Many can be asymptomatic
Failure to thrive as children diarrhoeas fatigue weight loss mouth ulcers anaemia secondary to iron, B12 & folate deficient Dermatitis Herpetiformis
Coeliac disease: associated skin manifestation - location and characteristics
Dermatitis Herpetiformis
a pruritic, vesicular skin rash caused by IgA deposition in the papillary dermis.
Locations: trunk, elbows and knees
Rare neurological symptoms of coeliac disease
peripheral neuropathy
cerebellar ataxia
epilepsy
Which metabolic condition is coeliac closely associated with?
T1DM. All new diagnosis will undergo coeliac screen.
2 genes associated with Coeliac
HLA DQ2 (most common) HLA DQ8
How would IgA deficiency affect coeliac diagnosis? What instead?
Anti-TTG & Anti-EMA & endomysium- IgA. If deficient, false negative finding.
All immunoglobulin screen required for all patients.
IgG antibody tests instead (Anti-TTG & Anti-EMA) or endoscopy + biopsy
Expected histological findings - Coeliac biopsy
Atrophy of intestinal villi
Hypertrophy of crypt cells
Intraepithelial lymphocytic infiltration
Diagnosis of Coeliac Disease?
What is patient requirement for investigations?
All investigations must be done while patient is on gluten diet - to detect antibodies and
Test IgA levels -> Anti-TTG antibodies test
Endoscopy with intestinal biopsy
Complications - Coeliac disease (auto-immune conditions)
All autoimmune disease.
T1DM, thyroid disease, Autoimmune hepatitis, Primary biliary sclerosis, Primary sclerosing cholangitis
Complications - UNTREATED coeliac disease
Vitamin D deficiency & anaemia (quick manifestation)
Osteoporosis
ulcerative jejunitis
enteropathy associated T-cell lymphoma (lymphoma of small intestine - EATL)
non-Hodgkin’s lymphoma
Treatment - Coeliac disease
Lifelong gluten-free diet (curative)
If ingest gluten - relapse of disease
What is the underlying pathogenesis of PSC & PBC?
Cholestatic liver disease
What are the differences between Primary sclerosing cholangitis and Primary biliary cholangitis/cirrhosis?
Location: intrahepatic & extra hepatic bile duct vs intrahepatic ONLY
Autoimmune: immune mediated vs true autoimmune disease
USDA
What are the differences between Primary sclerosing cholangitis and Primary biliary cholangitis/cirrhosis?
Location: intrahepatic & extra hepatic bile duct vs intrahepatic ONLY
Autoimmune: immune mediated vs true autoimmune disease
USDA efficacy: can improve blood results but no proof to prolong progression of disease vs can improve prognosis
What is the imaging finding for PSC? What is the gold standard imaging for diagnosis
MRCP - Beads on a string appearance
Definiton - PSC
Chronic, progressive condition characterised by the inflammation and scarring of the intrahepatic and extrahepatic bile ducts
Leading to harden and strictures (narrowing) leading to bile obstruction
Prevalance - PSC
Rare - 6/100,00 (under-diagnosis),
Male: female 2:1,
Age peak 30-40,
80% associated with IBD (UC)
Pathophysiology - PSC
Immune mediated (not true autoimmune), Genetic predisposition (HLA B2 (more common) & HLA D3), Disruption of biliary epithelial (iliac bacterial translocation leading to inflammation)
Chronic cycle of inflammation leading to more scarring -> cirrosis
Prognosis & Complications - PSC
Average survival - 15 years from diagnosis. Cirrhosis of biliary duct
Complications: cholangiocarcinoma (poor prognosis), hepatocellular carcinoma, gallbladder cancer, colorectal cancer & pancreatic cancer
Presentation - PSC
50% asymptomatic at diagnosis.
Fatigue, fever, diarrhoea, non-specific upper abdominal pain, High bilirubin (jaundice, pruritus), fat soluble vitamin deficiency (ADEK), cirrhosis
Diagnosis - PSC
Lab markers: ALP, AST/ALT, Auto- antibodies - Anti-smooth muscle & anti-nuclear antibodies, pANCA (80% of patients)
Gold standard: MRCP (bead on the string)
Treatment - PSC
No definitive treatment
- Liver transplants (high recurrence rate),
- UDCA - limited effect on improving survival/ symptoms.
- Cholestyramine (bile acid sequestrants) - relief pruritus.
- Immunosupressants/ antifribrotics (cyclosporine, tacrolimus & methotrexate) - no significant improvement