Gastroenterology Flashcards
Give 2 antibiotics that classically cause cholestatic LFTs.
Augmentin (due to clavulonic acid) and macrolide
What are the prognostic factors in the context of a paracetamol overdose?
Most important: time to NAC instigation being under 8h.
Others (GLAD):
- Glutathione deficiency: fasting/malnutrition, acute illness, HIV/AIDs
- Liver injury: viral / EtOH (acute intake)
- Alcohol use (chronic intake)
- Drugs that induce p450 (CRIB): carbamazepine, rifampicin, isoniazid, barbituates
Give 2 drugs that classically cause hepatocellular LFT derangement.
Diclofenac and isoniazid
What does Dubin-Johnson syndrome do to LFTs?
Genetic cause of elevated CONJUGATED bilirubin due to inability of hepatocyte to SECRETE bilirubin into bile.
NO changes in ALT/AST.
Which type of iron, haem vs. non-haem iron has higher bioavailability? What are the sources of these types of iron in the diet?
Haem iron (meat and fish) has higher bioavailability than non-haem (vegetables) iron.
What 4 ‘alarm bell’ clinical features that prompt one to think IBD rather than IBS?
B-PAW:
- Blood derangements: UEC/FBC/ESR/CRP
- PR bleeding
- Abdominal pain that is worsening
- Weight loss
What are 3 useful tests to ‘exclude’ coeliacs disease (i.e. high sensitivity)? What immunogloblin deficiency affects the sensitivity of one of these tests?
Excluding coeliac disease (unlikely if both negative):
- Serology:
EMA (endomysial Ab – IgA) - affect by IgA deficiency.
tTGA (tissue-transglutamase Ab) - Genotype: HLA-DQ2 or HLA-DQ8
What happens to the level of hepcidin with the following scenarios:
Increased body iron levels
Infection
Inflammation
Hepcidin levels increases congruently with increases in bodily iron levels, infection or inflammation.
What type of iron is dietary iron, ferrous or ferric?
Dietary iron is Fe2+ - ferrous/food/two (all have ‘o’ in it).
What are the DDx for atrophic villi on a bowel biopsy (6)? Which is most likely
CE-SCAM (think caecum):
Coeliac’s disease (most likely), Eosinophilic enteritis, Sprue (collagenous, tropical, hypogammaglobulinic), Crohn’s disease, Adult-onset autoimmune enteropathy, Malnutrition.
What are the most common long-term complications of liver transplantation?
Most common long-term complication of liver transplantation = metabolic syndrome (HOLD): HTN, obesity, lipid disorder, DM.
What is the significance of NOD1/CARD15 mutations?
NOD1 / CARD15 gene polymorphisms are implicated in Crohn’s diseases and suggest increased risk of need for Sx at a younger age and strituring disease.
What is Zollinger-Ellison syndrome (give 3 points).
Zollinger-Ellison Syndrome:
- Tumour of pancreatic islet of Langerhans (non-beta cells) that secretes gastrin which in turn stimulates parietal cells in the stomach to cause GI mucosal ulcerations.
- Part of MEN1 or sporadic
- Primary tumours = pancreas, duodenum and LN of abdomen (ectopics possible)
Which bacteria is known to cause terminal ileitis?
Yersinia may cause acute terminal ileitis
What are the 2 most common causes of pancreatitis?
Common causes of pancreatitis:
Gallstones and EtOH 80%
Idopathic 10%
Other (all) 10%
Give 3 GI causes of clubbing.
- IBD
- Coeliac’s disease
- Whipple’s disease
True/False: most cases of acute hepatitis are symptomatic.
False.
Acute hepatitis does NOT necessarily present with florid symptoms, as only 25% present with acute hepatitis and the rest are asymptomatic until they present with chronic liver failure.
Give 4 inherited disorders of bilirubin metabolism. Elucidate upon whether they are conjugated or unconjugated.
4 inherited disorders of bilirubin metabolism:
Conjugated (DC - has ‘C’):
- Dubin-Johnson syndrome
- Crigler-Najjar syndrome (types I and II)
Unconjugated (GR):
- Gilbert syndrome
- Rotor syndrome
Where is bilirubin normally conjugated?
Bilirubin is conjugated in the liver hepatocytes and catalysed by gluconyl transferase.
Give lots of causes of pancreatitis.
Causes of pancreatitis (IGETSMASHED)
Idiopathic approx 10%
Gall stones / EtOH approax 80%
Rest approx 10%:
Trauma/tumours
Scorpion/Snake venom
Microbiology (CHEP: CMV, hepatitis, EBV, paramyxovirus)
Autoimmune (PAN, SLE)
Steroids
Hypercalcaemia/Hypertriglyeridaemia/Hypothermia/Hereditary
ERCP/Estrogen
Drugs (sulphonamides, AZA, NSAIDs, diuretics) / Duodenal ulcers
What is the clinical triad for Zollinger-Ellison syndrome? What is the mechanism?
Clinical triad (PIG):
- PUD
- Isle of Langerhans cell tumour
- Gastric acid hypersecretion
Mechanism: Islet of Langerhans cell tumour → gastric hypersecretion → PUD
What is the significance of CAGA+ in PUD?
CAGA+ in H. pylori confer worse disease (PUD/GUD or gastric cancers)
What is Whipple’s disease?
Whipple’s disease is a chronic infection from Tropheryma Whipplei
What is the genetics of hereditary haemachromatosis?
Herediatary haemachromatosis has autosomal RECESSIVE inheritance and involve C282Y/H63D genetic mutations
What are constituents of total bilirubin?
delta bilirubin (conjugated bilirubin bound to albumin)
conjugated bilirubin
unconjugated bilirubin
True/False: anorexia nervosa leads to hypoalbuminaemia.
False.
Albumin levels remain normal in anorexia nervosa.
Patient has fatigue, pruritus and abdominal pain with jaundice. Bloods reveal positive anti-mitochondrial antibodies. Diagnosis?
Primary biliary cirrhosis.
Jaundice is a late sign.
What is the cell that is responsible for causing fibrosis in the liver?
Stellate cell
Patient presents with red-crusted lesions around the mouth and finger pulps 3m after SB resection for Crohn’s disease. What is the diagnosis?
Zinc deficiency – Acrodermatitis
Peri-oral dermatitis
Acral involvement
Occasionally alopecia
What is the IL28B genotype?
IL28B is a PATIENT genotype that affects Hep C viral kinetics
2 types:
CC (good) - responds well to treatment, so treat immediately
TT (bad) - responds poorly to treatment (Africans), no date for best treatment regimen.
Remember:
‘yum, these CCs are good!’
‘Tsk, Tsk! Don’t do that - that’s bad!’
IL28B genotype is an important predictive factor for which condition and what does it predict?
Hep C - IL28B is the single most important predictive factor.
- Treatment response to Peg-Riba (pegylated interferon and ribavirin)
- Sustained or spontaneous viral clearance.
What does it mean to have Hep C Genotype 1?
Genotype 1-3 are VIRAL genotypes that influence response to treatment:
Genotype 1 = BAD (type 1A is worse than 1B)
Genotype 2 + 3 = GOOD (but less common)
Remember: ‘Type A personalities almost wanna be no. 1 and are the worst!’
What is the new standard of care for Hep C with Genotype 1?
Pegylated interferon + Ribavirin + Protease inhibitors (triple therapy)
Example: Pega-Riba-Telaprevir or Pega-Riba-Boceprevir
What are the SEs of using triple-therapy in Hep C with Genotype 1?
Example: Pega-Riba-Telaprevir or Pega-Riba-Boceprevir
Both:
- Myelosuppression
- Riba (ribavirin) causes severe haemolytic anaemia.
SEs of Telaprevir:
1. ‘Fire-a-rrhoea’ - diarrhoea with anal pain
2. Rash 6%
Remember: ‘if you watch TELAvision all day, your ass will hurt’
SEs of Boceprevir:
1. Dygeusia - bad taste
2. Nausea
Remember: ‘this BOCconcini cheese left a bad taste in my mouth - it’s dyguesting!!’
What is the duration of therapy of Hep C triple therapy?
Trick question - depends.
Duration dictated by ‘response guided therapy’ - HCV RNA checked at 8 weeks:
- Undetectable then 24 weeks Rx
- Detectable then 48 weeks Rx
What is a new treatment available for Hep C?
How does it differ from the old regimen in terms of duration of treatment and indications?
Sofosbuvir and Ledipasvir.
Remember: ‘If nothing else works for Hep C then just hit themover the head with SOFT-LED’
Sofosbuvir is a polymerase inhibitor - direct antiviral agent.
- Duration of Rx = 12 weeks only
- 90% effective ALL genotypes with good SEs profile.
What are the phases of Hep B infection?
Phases of Hep B:
Phase I: immunotolerant (no liver disease, occurs in 80%)
Phase II: acute infection (first or acute flare on chronic Hep B)
Phase III: latent disease
Phase IV: pre-core mutant infection
What is occurs in phase IV Hep B?
Pre-core mutant infection:
- Host directs a lot of immune pressure towards eAG (eAg is only present in wild type virus
- Resulting in negative eAg but positive eAb
- Patient remains susceptible to flares of hepatitis from pre-core mutant therefore core IgM positive.
True/False: in the treatment of Hep C with triple therapy, failure of one type of protease inhibitor warrant the trial of another.
False.
Resistance to protease inhibitors is an issue in Hep C treatment.
What phase of Hep B infection does the following patients have: sAg+, eAg+, core IgM+/-, core IgG+, HBV DNA+, sAb-, eAb-
Active hepatitis: acute flare of chronic infection (phase II)
NB:
eAg indicates infection with wild-type virus
sAg indicated infection with any type (i.e. wild or mutant)
What phase of Hep B infection does the following patients have: sAg+, eAg-, core IgM+, core IgG+, HBV DNA+, sAb-, eAb+
Active hepatitis: pre-core mutant infection (phase IV)
NB:
eAg indicates infection with wild-type virus
sAg indicated infection with any type (i.e. wild or mutant)
What phase of Hep B infection does the following patients have: sAg+, eAg-, core IgM-, core IgG+, HBV DNA-, sAb-, eAb-
Latent disease (phase III)
NB:
eAg indicates infection with wild-type virus
sAg indicated infection with any type (i.e. wild or mutant)
What is the standard of care for a young patient with Hep B with Hep D coinfection?
How many respond well?
Is there risk of of decompensated liver disease?
Remember: ‘Be quick, you need to PEG the SINGLE YOUNG guy!’
Single agent PEG (pegylated interferfon) for 48 weeks.
1/3 of patient with sustained viral response.
Risk of decompensated liver disease.
What is the standard of care for an older patient with Hep B?
What types of drugs are used?
How many respond well?
Is there risk of decompensated liver disease?
Remember: ‘You can Be LATE for older guys!’
Lamivudine - problems with resistance
Adefovir
Tenofovir
Entecavir
All NARTi (nucleoside analogue reverse transcriptase inhibitors) that prevent viral replication.
95% with viral suppression but only 6% with sustained viral response.
Not much risk of decompensated liver disease.
What is the treatment of Hep B reactivation in pregnancy?
What is the perinatal consideration?
Lamivudine and Tebivudine (Lam-Telbi) at 32 weeks to prevent vertical transmission (10% risk if untreated)
12 prior to delivery give Hep B immunoglobulin,
What % of people with Hep B will develop cirrhosis?
What is the most important risk factor for this?
20% (high)
Hep B DNA viral load
What need to be found on the biopsy of the distal oesophagus to diagnose Barrett’s oesophagus?
Intestinal dysplasia.
What are the 6 risk factors for Barrett’s oesophagus?
‘Old fat white guy that smokes and has reflux’
>50yrs Overweight Male Caucasian Smoking GORD
True/False: PPIs are beneficial in the treatment of Barrett’s oesophagus.
True.
PPIs need to be lifelong.
For the following case of Barrett’s oesophagus comment on the timing of endoscopic surveillance:
- No dysplasia
- Low-grade dysplasia
- High-grade dysplasia in absence of eradication therapy.
- No dysplasia = 3-5yrs
- Low-grade dysplasia = 6-12m
- High-grade dysplasia in absence of eradication therapy = 3m
What is the risk of Barrett’s oesophagus with high-grade dysplasia progressing to cancer?
6%
Patient wil deranged LFTs (mixed picture) has a liver biopsy that reveals marked steatosis, portal and lobular inflammation and hepatocyte ballooning. What is the likely diagnosis?
NASH
What is the difference between NAFL (non-alcoholic fatty liver) and NASH (non-alcoholis steatohepatitis)?
NAFL = hepatic steatosis WITHOUT significant inflammation, benign.
NASH = hepatic steatosis WITH hepatic inflammation +/- fibrosis.
True/False: the majority of deaths from in patients with NASH are due to liver-related mortality.
False:
Most due to CVD and T2DM.
1/3 cases have liver-related mortality:
- Complication of liver cirrhosis
- HCC
What is the metabolic syndrome?
HOLD:
HTN
Obesity (central)
Lipid derangement (high TG and low HDL)
DM / insulin resistance
What are the principle in NASH management?
Treat metabolic and cardiovascular comorbidities.
A patient with Hep C infection is at increased risk of developing which condition?
T2DM
HCV causes insulin resistance by affecting insulin signalling pathways
Patient is noted to have both chronic HCV infection (treated) and T2DM, what is the patient at risk of (3)?
- Accelerated progression of liver fibrosis (via stimulation of stellate cells)
- Reduced SVR (sustained viral response) rates with PEG-Riba
- HCC development
In Crohn’s disease management, what is the utility of Budesonide?
Used as an alternative to prednisone for active ileitis or right-sided Crohn’s colitis.
Metabolite testing is often used in thiopurine (AZA, 6-MP) use in IBD. What do the following metabolites suggest:
- 6-TG
- 6-MMP
- 6-TG: therapuetic efficacy, high levels (>400) may cause bone marrow suppression
- 6-MMP: liver toxicity (>5000)
Explain the phenomena of shunting in AZA metabolism?
How is this addressed clinically?
Certain patients have low TMPT activity, this leads to excessive shunting of AZA to 6-TG (theperautic moiety).
At-toxic levels (>400) this causes marrow suppression and leucopenia.
If shunt is noted then reduced dose of AZA/6-MP +/- allopurinol (block XO but also inhibits TPMT)
Is the dosing of AZA and 6-MP equivalent?
No
1mg AZA = 0.5mg 6-MP
(only 50% of AZA metabolises to become 6-MP
TNFi are effective in what types of Crohn’s disease?
Luminal and fistulising Crohn’s Disease.
Define the following:
- Severe UC (ulcerative colitis)
2. Fulminant UC
1. Severe UC (ulcerative colitis) >6 stools/d Severe cramps Systemic toxicity (febrile and tachycardic) Anaemia Hb < 105 ESR > 30
2. Fulminant UC >10 stools/d + continous bleeding abdominal pain +/- acute abomen Systemic toxicity + anorexia Risk of toxic megacolon and bowel perforation
What is the treatment of severe UC?
If not responsive at 3-5d?
If still not responsive at 4-7d?
- IV hydrocortisone / Abx (broad) / supplements (fluid/electrolytes)
- Surgical review
- DVT prophylaxis
Not responsive at 3-5d = cyclosporin or TNFi (infliximab)
Not responsive at 4-7d = colectomy
Patient has stage 2 colon cancer, what are the risk factors for relapse?
Pathology:
- lymphovascuar invasion
- poorly differentatiated cells
- T4 disease
Clinical:
4. presents with obstructione
T/F: LN involvement is a feature suggestive of relapse in stage 2 colon cancers.
False