Gastroenterology Flashcards
Which of the follwoing cell types has a role in determining the body iron content and distribution?
A. Gastric parietal cells B. Microfold cells C. Goblet cells of the small intestine D. Reticuloendothelial macrophages E. Cardiac myocytes
Answer: D - Reticuloendothelial macrophages
Duodenal enterocytes absorb 1-2mg of iron/day to offset losses. Absorbed iron circulates bound to transferrin and is used primarily by erythroid precursors to synthesise haem. Reticuloendothelial macrophages clear senescent RBCs and release the iron from haem to export to the circulation or store it in ferritin. Hepatocytes are another site of iron storage as ferritin and the principal site of production of the hormone hepcidin (the iron regulator). Hepcidin blocks the release of iron from enterocytes and reticuloendothelial macrophages by degrading the iron exporter ferroportin.
Absorption of which of the following is affected by the resection of the distal ileum?
A. Bile salts B. Calcium C. Folate D. Iron E. Vitamin C
Answer: A - bile salts
Bile salts aid absorption of fat in the duodenum and jejenum and are reabsorbed in the distal ileum as part of the enterohepatic circulation.
Iron, folate, vitamin C and calcium are mainly absorbed in the proximal jejunum. The only vitamin absorbed in the ileum is vitamin B12, which requires intrinsic factor (a glycoprotein produced by gastric parietal cells).
Which one of the following is true of fructose?
A. Intake worldwide is reducing
B. It is less prone to promote hypertension than glucose
C. Fructose intolerance can present as a metabolic disorder in infancy
D. It is not malabsorbed
E. It is not as sweet tasting as glucose
Answer: C - Fructose intolerance can present as a metabolic disorder in infancy
Fructose is a simple sugar in fruit, dietary sugar and honey. Absorption is facilitated by insulin-independent transport (GLUT-5).
Intake is increasing (e.g. high fructose corn syrup) and is bad, causing metabolic syndrome and hypertension.
Which one of the following is a stimulus for gastrin secretion?
A. Calcitonin B. Adrenaline C. Glucagon D. Somatostatin E. Vasoactive inhibitory peptide (VIP)
Answer: B - Adrenaline
Gastrin stimulates secretion of gastric acid by the parietal cells of the stomach and aid gastric motility. It is released by G cells in the antrum of the stomach, duodenum and pancreas. It binds to CCK-B receptors to stimulate the K-H+ ATPase pumps.
Major stimuli for gastrin:
- Vagal stimulation
- Gastric distension
- Adrenaline
- Calcium
- Acetylcholine
- L-amino acids (phenylalanine, trytophan, cysteine, tyrosine)
Inhibitors of gastrin:
- Low pH <2
- Somatostain
- Calcitonin
- Gastric inhibitory peptide (GIP)
- Vasoactive inhibitory peptide (VIP)
- Glucagon
Which one of the following hormones increases appetite?
A. Glucagon B. Leptin C. Glucagon-like peptide 1 D. Ghrelin E. Lipase
Answer: D - Ghrelin
Ghrelin stimulates appetite through actions on the hypothalamic appetite centre.
Leptin and ghrelin are the 2 main regulators of energy balance.
Ghrelin stimulates appetite and increases pre-prandially and then reduces after eating. Ghrelin increases when humans lose weight to promote weight gain and appetite.
A 35 year old immigrant has hepatitis serology for investigation of abnormal liver function tests. He has a positive hepatitis B surface antigen (HbsAg) and IgM antibodies to hepatitis B core (anti-HBc). What is the most likely stage of infection?
A. Acute hepatitis B infection B. Chronic hepatitis B infection C. High levels of hepatitis B viral DNA in blood D. Inactive carrier E. Post vaccination changes
Answer: A - acute hepatitis B infection
HbsAg indicates active infection - when infection resolves then HBsAg becomes negative and anti-HBc (IgG) positive
There are 4 phases of HBV infection: immune tolerant, immune active, immune control (inactive chronic HBV), and reactivation.
- Immune tolerant = vertically acquired, no immune response
- HBsAg positive
- HBe-Ag positive usually
- Normal ALT (no inflammation or fibrosis)
- Uncontrolled HBV replication - DNA >1 million - Immune active = Chronic active infection
- HBsAg positive
- HBeAg can be positive or negative
- ALT elevated due to inflammation, fibrosis
- Anti HBc (IgM) early with IgG later
- HBV DNA elevated (>20,000 if eAg positive, >2000 if eAg negative) - Immune control = chronic inactive carrier
- Normal ALT
- HBeAg negative, anti-HBe positive (anti-HBe usually indicates immunity)
- No active inflammation but can have previous fibrosis
- HBV DNA <2000 - Reactivation = loss of immune control with immunosuppression
- Rise in HBV DNA
- Seroconversion from HBsAg negative to positive
A 35 year old woman presents with jaundice and lethargy. Her blood tests are shown below. Anti-mitochondrial antibody is positive. What is the liver biopsy likely to show?
Bilirubin 110 (2 - 24) ALP 650 ( 30 - 110) AST 240 (<45)
A. Granulomatous changes
B. Fatty liver parenchymal change
C. Piecemeal necrosis and fibrosis around portal veins
D. Collagen layering around bile ducts
E. Lymphocyte infiltrates causing biliary duct destruction
Answer: E - Lymphocyte infiltrates causing biliary duct destruction
This patient has primary biliary cirrhosis. Inflammation changes with biliary destruction are most suggestive of PBC.
Granulomatous changes would suggest sarcoidosis or GPA. Piecemeal fibrosis and necrosis suggests chronic hepatitis.
Primary biliary cirrhosis mostly affects middle-aged women and is characterised by progressive destruction of intrahepatic biliary ducts. Anti-mitochondrial antibodies are often positive.
Primary biliary cirrhosis is now diagnosed much earlier than in the past, 50-60% can be asymptomatic. Fatigue and pruritus are the most common symptoms. Over symptoms develop within 2-4 years in most asymptomatic patients. There are 4 histological stages but the liver is not affected uniformly and the biopsy can show all 4 stages at the same time. Stage 1 is localised portal triad inflammation –> stage 4 is end-stage with frank cirrhosis and regenerative nodules.
Primary sclerosing cholangitis (PSC) more commonly affects middle-aged men and often co-exists with ulcerative colitis. There is progressive inflammation of both intrahepatic and extrahepatic bile ducts.
Which one of the following best describes the faecal immunochemical test (FIT)?
A. Antibodies bind to haem portion of human Hb
B. FIT has higher clinical sensitivity in detecting occult blood at lower concentrations compared to guaiac-based testing
C. Digested blood from the upper GIT is often detected by FIT
D. Patients have to observe dietary restrictions before collecting a stool sample
E. FIT has higher false positive rate than guaiac-FOBT
Answer: B - FIT has higher clinical sensitivity in detecting occult blood at lower concentrations compared to guaiac-based testing
The FIT binds to the globin portion of Hb with high specificity. Patients do not need to observe drug or dietary restrictions and digested blood from the diet is not usually detected - more specific for lower GIT bleeding.
EMQ chronic liver disease
A. Alcoholic hepatitis B. Autoimmune hepatitis C. Chronic hepatitis B D. Haemochromatosis E. Hepatocellular carcinoma F. Primary biliary cirrhosis G. Primary sclerosing cholangitis H. Wilson disease
- 42year old woman presents with fatigue, nausea, abdominal pain and arthralgia. She does not drink alcohol. Her transaminases are markedly elevated >3x ULN. Her viral hepatitis serology is negative. Caeruloplasmin level is normal. Her liver biopsy shows dense portal and periportal predominance of plasma cell infiltrates with some lymphocytes.
- A 35 year old woman with a history of hypothyroidism on adequate thyroid replacement, presents with fatigue and pruritus. She has jaundice and enlarged liver on examination. Her ALP has been elevated for more than 6 months. Her liver biopsy shows portal inflammation and destruction of intrahepatic bile ducts.
- Answer: B - Autoimmune hepatitis (AIH)
Autoimmune hepatitis is an inflammatory liver disease mainly affecting women.
It is characterised by:
- Increased transaminases
- Serological autoantibodies & IgG
- ANA- Anti-smooth muscle antibodies (anti-SMA)
- Anti-liver-kidney-microsomal antibody (anti-LKM1/3)
- Pathological finding of interface hepatitis
- ‘lymphocytic’ piecemeal necrosis (periportal) usually with an abundance of plasma cells - Answer: F - Primary biliary cirrhosis
PBC is characterised by portal inflammation and immune-mediated destruction of intrahepatic bile ducts. Loss of bile ducts leads to decreased bile secretion with retention of toxic substances, worsening liver damage.
PBC is a slowly progressive autoimmune disease primarily of women in the 5th decade. Other common findings include hyperlipidaemia, hypothyroidism, osteopenia as well as co-existing autoimmune disease (Sjogren’s, scleroderma).
Serology is notable for anti-mitochondrial antibodies in 90-95% of cases, often detectable for years before clinically evident disease.
EMQ Nutrition/Bariatric surgery
A. Thiamine B. Folic acid C. Vitamin A D. Vitamin B12 E. Vitamin C F. Vitamin D G. Vitamin E H. Vitamin K
Deficiency of which is most likely to cause the following?
- 45 year old man presents with confusion and nausea. He had a Roux-en-Y bypass 2 years prior and has not been compliant with nutritional recommendations after surgery. Examination shows tachycardia and bilateral pitting oedema of the legs.
- 50 year old woman presents with visual disturbance 8 years after a Roux-en-Y bypass for morbid obesity. She does not have type 2 diabetes. Examination shows reduced visual acuity and bilateral conjunctival keratinisation with superficial punctuate keratopathy in the cornea.
Bariatric surgery remains an important treatment option for BMI>40 or BMI >35 with comorbidity, in whom lifestyle intervention or pharmacotherapy result in inadequate weight loss. The more effective options result in more malabsorption and risk of nutritional deficiency.
- Answer: A - thiamine
- Answer: C - vitamin A
Risk of fat soluble vitamin deficiency. Vitamin A deficiency can result in decreased vision, poor night vision, xerosis, corneal ulceration, retinopathy, itching and dry hair.
A 38 year old woman has a 10 year history of heartburn but has not received any treatment. Over the last 4 months, she has noticed progressive difficulty swallowing large bits of solid food. There is no difficulty with soft foods or liquids and she has not lost weight. Which one of the following is the most likely explanation for her symptoms?
A. Adenocarcinoma of the lower third of the oesophagus
B. Barrett oesophagus in the distal oesophagus
C. Distal oesophageal stricture
D. Schatzki ring of the distal oesophagus
E. Squamous carcinoma of the middle third of the oesophagus
Answer: C
Mechanical dysphagia may follow many years of reflux and is often indicative of a peptic stricutre as a result of fibrosis from chronic inflammation/GORD. Benign strictures can usually be dilated endoscopically.
A 65 year old woman with recently diagnosed renal cell cancer presents with abdominal pain and distension. She states that her abdomen has become more distended and painful over 3 weeks and she was afraid to come to hospital thinking this was further spread of her cancer. On examination there is a tender distended abdomen with moderate hepatomegaly and evidence of ascites. The hepatojugular reflux is absent. The abdominal veins are dilated in the flanks and over the back, along with pedal oedema. Which one of the following diagnoses is most likely?
A. Alpha1 anti-tripsyin deficiency B. Budd-chiari syndrome C. Constrictive pericarditis D. CMV hepatitis E. EBV infection
Answer: B - Budd-chiari syndrome
Budd-Chiari syndrome is a hepatic venous outflow obstruction (independent of the level of obstruction - but not due to cardiac disease) e.g. thrombosis or malignancy invasion.
Diagnosis is usually by venous phase CT scan which shows filling defect in the hepatic vein or IVC. USS may show retrograde flow in the portal system.
A 28 year old woman was found to have an elevated bilirubin on a pre-operative blood test. She has no other significant medical history and is only taking the OCP with no other over-the-counter medications. Examination is unremarkable. Her Hepatitis A, B and C serology are all negative. Her other investigations are shown below. Which is the most appropriate next step in her management?
Hb 139 (normal) Bilirubin 39 ( 2 - 24) ALP 65 (normal) AST 34 (<45)
A. Investigation for presence and cause of haemolysis
B. Abdominal ultrasonography before surgery
C. Discontinuation of the OCP permanently
D. Half the recommended dose of paracetamol post-surgery
E. Recommended dose of morphine peri-operatively
Answer: E - Recommended dose of morphine peri-operatively
Presentation consistent with Gilbert syndrome, a mild form of unconjugated hyperbilirubinaemia. It is a relatively common and benign finding in healthy individuals. Is is caused by impaired conjugation of bilirubin in the liver.
Conceivably, elimiation and glucoronidation of drugs could be affected with different pharmacokinetic profiles but there is no clear indication of clinical significance or toxicities in affected subjects
Which one of the following is a predictor of favourable response to peg-interferon and ribavirn therapy in previously untreated immunocompetent patients with chronic hepatitis C infection?
A. HCV genotype 1 B. High hepatitis RNA levels C. Absence of cirrhosis D. Age over 50 years E. Normal transaminases
Answer: C - Absence of cirrhosis
(In the old days), treatment of chronic HCV included combination IFN once a week and oral ribavirin. Predictors of response included:
- Non- genotype 1
- Low HCV RNA level
- Absence of fibrosis
- Age <40yrs
A 27 year old woman who has not travelled aborad in the last 2 years presents with 8 months of abdominal discomfort and diarrhoea up to 4x/day. There is no history of rectal bleeding or weight loss. Her CBE, CRP, biochemistry and coeliac serology are normal. She has tried a lactose-free diet for the last 2 months with no improvement. What is the next most appropriate test?
A. Colonoscopy B. Hydrogen breath test C. Pancreatic function testing D. Trial of anti-spasmodic therapy E. Computed tomography of the abdomen/pelvis
Answer: D - Trial of anti-spasmodic therapy
Presentation consistent with irritable bowel syndrome (IBS) - low doses of anti-diarrhoeals, anti-spasmodics or peppermint oil may provide relief.
IBS is characterised by chronically recurring abdominal pain or discomfort and altered bowel habits. Female: male ratio 2:1 and some develop following gastroenteritis infections. It can generally be diagnosed based on history and normal examination, laboratory findings (not colonoscopy) in the absence of red flags.
A 60 year old woman has epigastric pain for several months and is referred for endoscopy. Gastric biopsy confirms mucosa-associated lymphoid tissue (MALT) lymphoma and the presence of H. pylori. Further evaluation confirms localised gastric involvement. What is the next most appropriate treatment?
A. Amoxicillin, Clarithromycin, Omeprazole B. Oral cyclophosphamide C. Radiotherapy D. Rituximab E. Total gastrectomy
Answer: A - H. pylori eradication therapy
MALT lymphoma makes up about 7% of all NHL and can arise at any extranodal site but 1/3 as primary gastric cancer. Most in the stomach are associated with H. pylori infection.
H. pylori eradication therapy should be employed as the sole initial treatment of localised (i.e. confined to stomach H. pylori positive MALT lymphoma. Eradication can induce regression and long-term disease control in most patients.
A 52 year old woman presents with an 8 month history of chronic non-bloody watery diarrhoea. Faecal leukcocytes are presents but stool cultures are negative. CRP is mildly elevated. Barium enema and colonoscopy were normal but biopsy reveals increased intraepithelial lymphocytes within the epithelium. What is the most likely diagnosis?
A. Microscopic colitis B. Crohn disease C. Ulcerative colitis D. Pseudomembranous colitis E. Irritable bowel syndrome
Answer: A - Microscopic colitis
Microscopic colitis is a clinical syndrome characterised by chronic watery diarrhoea, grossly normal appearing colonic mucosa and abnormal histological features.
There may be patchy colonic involvement. One of the features of lymphocytic colitis subtype is an increase in intra-epithelial lymphocytes. Initial treatment involves avoidance of caffeine, alchol, dairy and possible contributing medications (e.g. aspirin, lansoprazole, ranitidine, NSAIDs, sertraline). Anti-diarrhoeals or choleystramine can be effective. Budesonide, bismuth and sulfasalazine can also be used.
A 60 year old man presents with 1 week history of non-specific epigastric pain. His history includes hypertension, gout, hypercholesterolaemia and obesity with BMI 38. He is currently taking ramipril 10mg daily, allopurinol 300mg daily and atorvastatin 30mg daily. He does not drink alcohol. Examination is normal and his LFTs are normal. liver USS reveals features of hepatic steatosis. what is the next most appropriate step in his management?
A. Liver biopsy B. Commence metformin C. Commence ursodeoxycholic acid D. Immediate referral for bariatric surgery E. Continue atorvastatin
Answer: E - Continue atorvastatin
Hepatic steatosis most likely reflects NAFLD in setting of obesity. There are no symptoms/signs/biochemical abnormalities to support biopsy.
The risk of progression to cirrhosis is minimal. In contrast, NASH with hepatic steatosis and inflammation with hepatocyte injury (ballooning), can proress to cirrhosis, liver failure and rarely HCC.
Weight loss of at least 3-5% is necessary to improve steatosis but usually a greater amount e.g. 10% is needed.
A 73year old man presents with 2 months of regurgitation of his food and foul smelling breath. He describes the regurgitated food as slightly changed but denies any blood or pain when he eats. He has not lost any weight recently and is otherwise fit and well. Which of the following diagnoses is most likely?
A. Gastric outlet obstruction B. Mallory-Weiss tear C. Oesophageal carcinoma D. Pharyngeal pouch E. Plummer-Vinson syndrome
Answer: D - Pharyngeal pouch
Classical description of pharyngeal pouch. These occur more in elderly patients, men more than women. Features of halitosis, regurgitation of saliva and food previously consumed. Diagnosed by barium swallow.
The earliest phenotypic manifestation of idiopathic hereditary haemochromatosis is:
A. Post prandial increase in serum iron concentration B. Elevated serum ferritin C. Slate grey pigmentation of the skin D. Increased transferrin saturation E. Jaundice
Answer: D - Increased transferrin saturation
Increased transferrin saturation is the earliest feature. Most homozygotes for C282Y mutation with iron overload demonstrate this.
A 45 year old man presents with lethargy, abdominal discomfort, jaundice and pruritus. The results of investigations are shown below. Anti-nuclear antibody and anti-mitochondrial antibody is negative. USS abdomen shows normal intrahepatic and extrahepatic bile ducts. The gallbladder is mildly enlarged and liver parenchyma show prominent periportal echogenicity. Which one of the following is the likely diagnosis?
Bilirubin 86 (2 - 24) Albumin 35g/L (34 - 48) ALP 1200 (30 - 110) ALT 150 (<55)
A. Autoimmune hepatitis B. Cholangiocarcinoma C. Chronic active viral hepatitis D. Primary biliary cirrhosis E. Primary sclerosing cholangitis
Answer: E - Primary sclerosing cholangitis
PSC represents a chronic cholestatic disease with fibro-obliterative sclerosis of intra and extra hepatic bile ducts, leading to biliary cirrhosis.
Though thought to be autoimmune in origin, it responds poorly to immunosuppressive therapy.
PSC is usually seen in males in the 5th decade and is typically associated with ulcerative colitis. 15-55% are asymptomatic a time of diagnosis. Fatigue, pruritus, jaundice or abdominal discomfort are most common.
p-ANCA is present in 80% but lacks specificity. Best investigation is with ERCP which will demonstrate multiple biliary strictures.
Which of the following patients with acute non-typhoid salmonella gastroenteritis requires antibiotic treatment?
A. Fever >48 hours B. Diarrhoea >48 hours C. Constant abdominal pain 24 hours D. Sickle cell disease E. Internation travel a month prior to presentation
Answer: D - Sickle cell disease
Most cases are self-limiting and resolve within 5-7 days. Antibiotic therapy increases carrier rate and adverse effects (Cochrane review).
Antibiotics are only indicated for those at risk of high morbidity: infants <2 months, elderly, immunocompromised, prosthetic valves/grafts, sickle cell disease
A 50 year old man with a 7 year history of cirrhosis caused by hepatitis C and alcohol is seen regularly in the liver clinic. What is the most appropriate surveillance for hepatocellular carcinoma?
A. Transaminases every 3 months B. AFP every 6 months C. USS every 12 months D. Serum AFP and liver USS every 6-12 months E. CT abdomen every 12 months
Answer: D -Serum AFP and liver USS every 6-12 months
A 62 year old man presents with malaena, dizziness and abdominal discomfort. On examination, his BP is 85/40 and HR 105bpm. After initial resuscitation and assessment, he underwent an urgent endoscopy which revealed a duodenal ulcer and non-bleeding vessel is visible. He was treated with adrenaline injection and thermal therapy. Gastric biopsy was positive for H. pylori infection. Which one of the following statements concerning his management is correct?
A. The risk of further bleeding is high because he did not received pre-endoscopy pantoprazole
B. He should receive oral pantoprazole 40mg BD for 3 days
C. He should have repeat endoscopy at 24 hours
D. He should be fasted for 72 hours after endoscopy
E. After confirmation of eradication of H. pylori, long-term PPI is not recommended
Answer: E - After confirmation of eradication of H. pylori, long-term PPI is not recommended
Pre-endoscopic PPI may reduce the proportion of patients with high risk stigmata of haemorrhage and need for endoscopic therapy. They do not improve clinical outcomes of further bleeding, surgery or death.
UGI Endoscopy should be done within 24 hours of admission following resuscitation.
Routine re-look endoscopy is not recommended. Only performed if recurrent bleeding.
High risk patients are generally hospitalised for 3 days and usually allowed clear fluids after endoscopy.
A 45 year old woman has rectal bleeding during bowel movements for 10 weeks. She has intermittent diarrhoea and severe lower abdominal pains. Her appetite is poor and she has also lost 7kg in weight. On examination she has a tender left lower abdomen and active bowel sounds. Rectal examination reveals a small streak of blood. her investigations are shown below. A rigid sigmoidoscopy shows inflammatory changes with multiple ulcerations and numerous areas of petechial haemorrhages. Elevated sessile reddish nodules (small and multiple) appear on the flat surface. There are multiple confluent ulcers leading to denudation of the mucosa.
Hb 111 (135 - 175) WCC 13.5 (4 - 11) Plat 600 (150 - 450) Urea 6.0 (2.7 - 8) Creatinine 100 (50 - 100) CRP 80 (<10)
A. IV hydrocortisone B. IV metronidazole C. IV 5-aminosalicylate D. IV anti-TNFalpha antibody infusion E. IV gamma globulin infusion
Answer: A - IV hydrocortisone
Acute severe ulcerative colitis. IV steroids should be used.
In mild cases then 5-ASA (e.g. sulfasalazine) can be used with expected remission rate of about 50%. Mild-moderate proctitis can be treated with mesalazine enemas.
