Intestinal disorders Flashcards
Pancreas : Name the different cells found in the pancreas and their function?
The pancreas consists of
1. Alpha cells : produce glucagon
2. Beta cells : produce insulin
3. Acinar cells : produce digestive enzymes into the duodenum to help break down macromolecules.
* Acinar cells manufacture inactive form of enzymes called proenzymes or zymogens
* Zymogens are activated by trypsin a pancreatic enzymes whose inactive form in trypsinogen
Pancreatitis : Definition
Sudden inflammation and haemorrhaging of the pancreas due to destruction by its own digestive enzymes.
Pancreatitis : Pathophysiology
- Acinar cells : produce digestive enzymes into the duodenum to help break down macromolecules.
- Acinar cells manufacture inactive form of enzymes called proenzymes or zymogens
- Zymogens are activated by trypsin a pancreatic enzymes whose inactive form in trypsinogen
- Trypsinogen is activated into trypsin by enteropeptidase enzyme which is found in the duodenum
- If trypsinogen or other digestive enzymes become activated whilst still in the pancreas - they can break down pancreatic tissue resulting in pancreatitis
Pancreatitis : Risk factors
Alcohol abuse -
1. Increases zymogen secretion and reduces fluid and bicarbonate release from epithelial cells
2. Making pancreatic fluid very viscous which blocks the pancreatic duct,
3. Increases pressure - damages acinar cells which release zymogens which then can get into contact with digestive enzymes thus becoming pre maturing activated.
Gall stone blockage of the pancreatic duct -
1. Increase in pressure and damage to acinar cells resulting in hydrolysis of the digestive enzymes and hence the pancreatic tissue
Pancreatitis : Causes
G E T S M A S H E D
-Gallstone, Ethanol, Trauma, Steroids, Mumps, Autoimmune, Scorpion venom, High cholesterol/Hypercalcaemia, hypothermia, ERCP, Drugs
Pancreatitis : Precipitant drugs
- Azathioprine,
- Thiazide, furosemide,
- Steroid,
- Sodium valproate
Pancreatitis : Complications
Pancreatic pseudocyst
Pancreatitis : Clinical features
- Epigastric pain - radiating to the back assoc with vomiting
- Severe epigastric tenderness
- Cullen’s sign - periumbilical discolouration
- Grey-turner’s sign - flank discolouration
Pancreatitis : Investigations for diagnosis
Lab results;
1. Serum amylase levels >3 x upper limit, does not correlate with disease severity
Not specific - also be due to pseudocyst, cholecystitis
2. Serum lipase - higher sensitivity and specificity and has a higher half life for later presentation
3. CT scan - to confirm diagnosis
Pancreatitis : How is severity graded?
GLASGOW scoring system - to identify severity of pancreatitis; factors in severe pancreatitis include;
* age>55, hypocalcaemia, hyperglycaemia, hypoxia, neutrophilia, elevated LDH and AST
Chronic pancreatitis : Definition
Long term inflammation of the pancreas leading to irreversible damage to the pancreatic tissue.
Chronic pancreatitis : Clinical features
- Chronic abdominal pain
- Steatorrhea
- Diabetes
Chronic pancreatitis : Investigations for diagnosis
- Abdominal X-ray - shows pancreatic calcification
- CT abdomen - higher sensitivity
- Faecal elastase - a human pancreas specific enzyme, can diagnosis pancreatic exocrine insufficiency
Chronic pancreatitis : Management
Pancreatic enzyme supplementation
Chronic pancreatitis : HIV and Pancreatitis
Pancreatitis in a patient with HIV may be due to;
* Antiretroviral therapy - esp didanosine
* Opputurnistic infection such as CMV
Pancreatic cancer : Risk factors
- Genetic predisposition - BRCA2 gene is the most common genetic cause
- Smoking - increases risk by 2-5x
- Obesity
- Diabetes, chronic pancreatitis and liver cirrhosis which also have a link to alcohol excess
Pancreatic cancer : definition
- Pancreatic adenocarcinoma account for 90% of pancreatic cancer
- They arise in the pancreas’s exocrine tissue within its epithelial cell lining
- Typically found at the head or neck of the pancreas
Pancreatic cancer : Clinical features
- Anorexia, weight loss
- Epigastric pain radiating the back - worse on lying down
- Steatorrhea - dysfunctional release of pancreatic enzyme prevent fat in food from being broken down fully
Pancreatic cancer : Clinical signs
- Trousseau sign - blood clots visible under the skin
- Courvoisier sign - gall bladder is enlarged, palpable but non tender
-occurs when common bile duct is blocked by the tumor
-indicating tumor likely to be at the head of the pancreas
* If blocking the common bile duct } leading to obstructive jaundice - can cause pruritus from leak of bile salts.
Pancreatic cancer : Labs and tumor markers
- Serum amylase and lipase elevated
- CA 19-9 antigen
- CEA
Pancreatic cancer : Management
Chemotherapy and Whipple’s procedure
Coeliac disease : Definition
- Autoimmune condition caused by sensitivity to gluten
- Repeated exposure leads to villous atrophy which in turn leads to malabsorption.
Coeliac disease : Other disease association
- Dermatitis herpetiformis : a vesicular pruritic skin eruption
- Autoimmune disorders : type 1 DM, autoimmune hepatitis
- HLA-DQ2, HLA-DQ8
Coeliac disease : Clinical features
- Chronic or intermittent diarrhoea
- Failure to thrive
- N+V
- Recurrent abdominal pain, cramping
- Unexpected weight loss
- Unexplained iron deficiency anaemia
Coeliac disease : Serology for diagnosis
- Tissue transglutaminase IgA + IgA levels are } FIRST LINE
- Endomyseal antibody IgA
- Anti-gliadin antibody
Coeliac disease : Investigation for diagnosis
- Endoscopic intestinal biopsy - Gold standard, - - gluten should remain in the diet for at least 6 week prior to testing
Coeliac disease; - Villous atrophy
- Crypt hyperplasia
- Increase in intraepithelial lymphocytes
- Lamia propia infiltration with lymphocytes
Coeliac disease : management
- Gluten free diet - TTG antibodies can be checked to confirm compliance with gluten-free diet
- Pneumococcal vaccine once every 5 years - patient have a degree of functional hyposplenism
Whipple’s disease : Definition
Rare malabsorbtive infectious disease caused by bacteria Tropheryma whipplei
Whipple’s disease : Pathophysiology
- G+ bacteria which spreads through out body causing multi-system effect, evade immune system so bacilli accumulates in body tissues.
- Transmission : Faecal - oral route
- Genetic assoc : HLA - B27
Whipple’s disease : Risk factors
- Immunosupression
- middle aged caucasian males, exposure to faecal matter (sewage workers, farmers)
Whipple’s disease : Clinical features
- W - weightloss,
- Hyperpigmentation,
- Infection with tropheryma whippelii,
- Pas positive granules in macrophages,
- Polyarterisis
- Lymphadenopathy
- Enteric involvement
- Steatorrhea
Whipple’s disease : Clinical signs
Skin
* Lymphadenopathy
* Hyperpigmentation
* Photosensitivity
Systemic
* Endocarditis
* Pericarditis
Whipple’s disease : Investigations for diagnosis
- Colonoscopy + jejunal biopsy - deposition of macrophages containing Periodic acid-Schiff granules
Whipple’s disease : Management
Oral co-trimoxazole for 1 year - lowest relapse rate
Ulcerative colitis : Definition
inflammatory bowel disease originating at the rectum and does not spread beyond the ileocaecal valve.
Ulcerative colitis : Incidence
Peak incidence : 15-25 years and 55-65 years
Ulcerative colitis : Clinical features
Bloody diarrhoea
Urgency
Tensesmus
Abdominal pain - lower left quadrant
Ulcerative colitis : Extraintestinal clinical features
- Arthritis
- Primary sclerosing cholangitis,
- Uveitis
Ulcerative colitis : Investigations for diagnosis - Colonoscopy
- Colonoscopy + biopsy -
-In severe colitis - a flexible sigmoidoscopy is preferred
*Typical findings
1. No inflammation beyond submucosa
2. Widespread ulceration with preservation of adjacent mucosa - appearance of polyps also known as ‘pseudopolyps’
3. Inflammatory cell infiltrate in lamina propia
4. Crypt abscess caused by neutrophil migration
5. Fewer goblet cells and mucin in the gland epithelium
Ulcerative colitis : Investigations for diagnosis - Barium enema
- Loss of haustrations
- Superficial ulceration, pseudopolyps
Ulcerative colitis : what are the results seen in barium enema in long-standing disease
In long-standing disease; colon is narrow and short - ‘Drain pipe colon’