General gastro Flashcards
1
Q
How long must antibiotics and PPIs be withheld before testing for H. pylori?
A
4 weeks Abx, 1-2 weeks PPI
2
Q
What test is used to diagnose H. pylori?
A
C13 or C14 urea breath tests - better than faecal or serum tests
3
Q
What is the biggest risk factor for cholangiocarcinoma?
A
Primary sclerosing cholangitis
Also: smoking, HBV, EtOH, fatty liver disease, DM, obesity, IBD
4
Q
Risk of which cancers is increased with primary sclerosing cholangitis?
A
Colon, bile duct, gall bladder
5
Q
What % of those with PSC also have IBD?
A
70-80%
6
Q
What are the most common signs at PSC diagnosis?
A
Hepatomegaly and splenomegaly
7
Q
What % of those with PSC have overlap with autoimmune hepatitis?
A
35% of children and 5% of adults
8
Q
How does serum IgG4 level correspond with outcomes in PSC?
A
Elevated IgG4 levels => worse prognosis
Not to be confused with IgG4 disease, which can cause secondary sclerosing cholangitis, demonstrates IgG4-positive lymphoplasmacytic infiltration of organs, and is steroid-responsive.
9
Q
Which IBD is more associated with PSC?
A
UC>CD
All new Dx PSC should have a colonoscopy
10
Q
How is colon cancer risk affected by PSC?
A
Those with PSC + IBD are more likely to develop CRC compared with IBD alone
11
Q
What deficiency causes porphyia cutanea tarda?
A
Uroporphyinogen decarboxylase
12
Q
What factors contribute to porphyria cutanea tarda?
A
EtOH, HCV, haemochromatosis, oestrogen
13
Q
Name 3 drugs associated with jejunal villous atrophy
A
Olmesartan, MMF and AZA
14
Q
Why is ammonia elevated in liver failure?
A
It is usually produced in the colon, enters the portal system and is broken down via the urea cycle in the liver
15
Q
How does hyperammoniaemia cause cerebral oedema?
A
Ammonia is converted to glutamine by astrocytic glutamine synthatase - this acts as an osmolyte.
16
Q
What are the first line treatments for hepatic encephalopathy?
A
Lactulose 25mL BD - titrate to achieve 3 stools daily
IV L-ornithine-L-aspartate - provides alternative urea cycle substrate
Rifaximin 550mg BD
Probiotics
17
Q
Which HLA genes are most strongly associated with coeliac disease?
A
DQ2 (95%) and DQ8 (80%)
18
Q
What are the diagnostic tests in HCV?
A
HCV Ab
- Screening test
- Low false positive rate if risk factor/raised ALT
- False negs if immunosuppressed or window period (6 weeks)
- Does not distinguish between active and resolved disease
HCV RNA
- Uses PCR
- Most specific for active infection
- Usually positive at 1-2 weeks
19
Q
How are qualitative and quantitative HCV RNA tests used?
A
Qualitative
- Used to diagnose infection or test for cure
Quantitative
- Reflective of viral burden
- Predictor of response to IFN
20
Q
What % of the world’s population has had HBV infection?
A
30%
21
Q
What % of neonates, children and adults infected with acute HBV develop chronic infection?
A
95%, 20-30% and <5% respectively
22
Q
What % of those infected with HBV seroconvert within a year?
A
10-20%
23
Q
Which HBV genotype is most associated with HCC?
A
Genotype C
24
Q
What is a precore mutant form of HBV?
A
HBeAg negative, increased risk of cirrhosis and HCC
25
What % of HBV-associated HCC develop without cirrhosis?
20%
26
Which HCV genotype is associated with steatosis and increased progression to cirrhosis and HCC?
Genotype 3
27
Which 2 extrahepatic manifestations are most associated with HCV?
Cryoglobulinaemia
| Porphyria cutanea tarda
28
Name 3 non-invasive tests used to rule out cirrhosis
Fibroscan
APRI (AST:platelet ratio index)
Hepascore
29
Which direct acting antivirals cannot be used in severe liver failure?
Protease inhibitors
30
Which SE are reduced in tenofovir alafenamide (TAF) vs tenofovir disoproxil fumarate (TDF)?
Renal impairment and osteoporosis
31
When should treatment be stopped in HBV treatment?
In HBeAg negative – when HBsAg is cleared
| In HBeAg positive – HBeAg seroconversion and 12 months consolidation
32
How should babies of HBsAg pos mothers be treated?
HBIG and 3 x vaccinations
33
What is the most common cause of acute hepatitis globally?
HEV
34
What are the criteria for radiographic diagnosis of HCC?
>1cm AND MDCT/Gad-enhanced MRI with arterial hyperintensity AND washout on delayed or venous phase.
35
What are the therapeutic options in HCC?
- 1 nodule < 2cm => Transplant if portal HTN / high bili. Resect if not. Ablate if resection contraindicated.
- 1 nodule < 3cm => Transplant if portal HTN / high bili. Resect if not.
- Up to 3 nodules < 3cm => Transplant if possible. Otherwise ablate.
- Multinodular => TACE
- Portal invasion, extrahepatic spread => sorafenib
- Child-Pugh C => supportive care
36
What is the most common cause of acute liver failure?
| What are other common differentials?
HBV
DDx:
- HAV, HEV, HSV, EBV, Parvovirus B19
- Paracetamol, antiepileptics, anti-TB drugs
- Amanita phalloides (death cap mushroom)
Uncommon DDx:
- AIH, malignancy, ischaemic hepatitis, Wilson's disease, acute fatty liver of pregnancy, Reye syndrome, Budd-Chiari syndrome
37
What are the King's College criteria for liver transplant in paracetamol overdose?
1. pH < 7.25 after fluids + NAC + 24hrs
OR
2. INR > 6.5 AND Cr > 300/anuric AND grade 3/4 encephalopathy
38
What are the King's College criters for liver transplant in non-paracetamol overdose?
```
INR > 6.5
OR
3 out of 5:
- INR > 3.5
- Bili > 300
- Jaundice to encephalopathy > 7 days
- Age < 10 or > 40
- Unfavourable aetiology (seronegative, drugs)
```
39
What is the most significant variable predictive of death in acute liver failure?
Encephalopathy
40
What is the most common cause for liver transplantation in Australia?
Hepatitis C
41
What are the 4 most common causes of cirrhosis?
EtOH > Hep C > Hep B > NAFLD
42
What are the components of the Child-Pugh-Turcotte score?
```
A BEAP:
Albumin
Bili
Encephalopathy
Ascites
PT (INR)
```
Predictive of 2yr survival
43
What are the cut-off scores for Child A, B and C?
```
5 = A
7 = B
10 = C
```
44
What are the components of the MELD score?
| What is it used for?
Cr, bili and INR
| MELD 20 or more = transplant candidate
45
What portal pressure is necessary for ascites to develop?
12mmHg
46
What should be used to treat spontaneous bacterial peritonitis?
Ceftriaxone or cefotaxime
47
What is the difference between Type 1 and Type 2 hepatorenal syndromes? Which has a poorer prognosis?
Type 1 = acute
Type 2 = chronic (eGFR<60 for >3months)
Type 1 is worse
48
What hepatic-venous-portal gradient and what variceal pressure is predictive of variceal bleeding?
HVPG > 12mmHg (normal 1 - 5mmHg)
| Variceal pressure > 15mmHg
49
At what hepatic-venous-portal gradient (HVPG) do varices form?
10mmHg
50
Who should receive primary prophylaxis against variceal haemorrhage?
Cirrhotics
- Child B or C
Large varices
- Red wale sign
51
What is first choice for primary prophylaxis against variceal haemorrhage?
Propranolol > endoscopy band ligation > carvedilol
52
What is the pathological hallmark of NASH?
Hapatocyte ballooning
| - Also Mallory body formation (damaged intracellular intermediate filaments)
53
What is used in secondary prophylaxis of spontaneous bacterial peritonitis?
1. Bactrim
| 2. Norfloxacin
54
What is the most important determinant of survival in NAFLD?
Fibrosis
55
What are the 2 most common causes of death in NAFLD?
Malignancy and IHD
56
What genetic variant is most associated with NAFLD?
PNPLA3
57
What is the mechanism of action of acamprosate in alcoholism?
It stimulates GABA receptors, thereby inhibiting glutaminergic activity. This minimises withdrawal symptoms.
58
How does baclofen work in alcohol dependence?
Stimulates GABA (B) receptors, reducing cravings for EtOH.
59
Which 2 HLA alleles are associated with Type 1 Autoimmune Hepatitis? How do the 2 groups differ?
```
HLA-DR3:
- Early-onset, severe form, seen in girls and young women.
HLA-DR4:
- Older patients
- More extrahepatic manifestations
- Better response to steroids
```
60
What is required for diagnosis of primary biliary cholangitis (PBC)?
ALP > 1.67xULN for 6 months
AMA positive
Typical liver biopsy
61
Which autoimmune condition is most associated with autoimmune hepatitis?
Thyroid disease
62
What is the first line treatment for autoimmune hepatitis?
Prednisone + Azathioprine
63
Who should have a liver biopsy in PSC?
1. To exclude other causes of liver disease if diagnosis uncertain
2. To determine the stage of PSC for therapeutic purposes
3. To diagnose small duct PSC:
- IBD + cholestatic LFTs + normal imaging => biopsy
64
How does smoking affect risk of development of PSC, and risk of cholangiocarcinoma in those with PSC?
- Smoking reduces risk of PSC developing
| - Smoking increases risk of cholangioacarcinoma in those with PSC
65
What is the sensitivity of bloody stools in ulcerative colitis?
95%
66
What is the distribution of disease in Crohn's Disease in different parts of the GIT?
Terminal ileum only > ileocolic > colonic only > small bowel
67
Which patients with ulcerative colitis would benefit from appendicectomy?
Age < 20 years old with Hx of appendicitis or mesenteric adenitis
68
Where is calprotectin produced?
Neutrophils and monocytes
69
How are anti-Saccharomyces cerevesiae antibodies (ASCA) and pANCA used in the diagnosis of IBD?
CD: ASCA + / pANCA -
UC: ASCA - / pANCA +
70
In which form of IBD are aminosalicylates (5-ASA) more effective?
What are the available options?
UC
- Sulfasalazine
- Mesalamine
- Olsalazine
- Balsalazide
Give topical (suppositories/foams/enemas) in left sided disease.
Mnemonic: UCASA (UC = 5-ASA treatment)
71
When should budesonide be used in IBD?
UC to control disease flare, while awaiting immunomodulators to kick in.
CD as initial therapy
72
Which IBD patients benefit from thiopurines (AZA and 6-MP)?
```
CD
- At diagnosis
- With first course of steroids
UC
- In severe UC requiring hospitalisation
- Steroid-refractory UC despite optimal dose ASA`
```
73
What are the side effects of thiopurines?
```
Nausea
Leucopenia
Fever, rash, arthritis
Infections
Hepatitis (hepAZAtitis)
Pancreatitis (pancreAZAtitis)
```
74
Which IBD patients benefit from methotrexate?
- CD unresponsive to or intolerant of optimised thiopurine.
| - Young males: increased risk of hepatosplenic T cell lymphoma with long term anti-TNF agents and thiopurines.
75
Which IBD patients benefit from cyclosporin?
Acute UC requiring hospitalisation
| - Use in thiopurine naive patients until maintained on thiopurine.
76
What is the treatment algorithm for Crohn's Disease?
Induction Rx:
- Budesonide first line
- Prednisone or 5-ASA second line
Maintenance Rx:
- Induction with steroids => taper off
- Induction with 5-ASA => continue 5-ASA
- AZA, 6-MP, MTX, Anti-TNFα, or Vedolizumab in moderate to severe CD
- Anti-TNFα: infliximab, adalimumab or certolizumab
- Vedolizumab (as alternative to TNF blockers)
- Ustekinumab - IL-12 and IL-23 receptor blocker
77
What is the treatment algorithm for Ulcerative Colitis?
Induction Rx:
- 5-ASA (topical>oral)
- Resistant to above => topical 5-ASA + topical steroid foam
- Resistant to above => oral and topical 5-ASA + topical steroid
- Resistant to above => oral steroids
- Steroid-resistant => cyclosporin, Anti-TNFα, or Vedolizumab
Maintenance Rx:
- No Rx if first episode proctitis
- Topical 5-ASA
- If resistant to above => topical + oral 5-ASA
- If resistant to above => AZA, 6-MP, Anti-TNFα, or Vedolizumab
78
What is the mechanism of action of vedolizumab?
- Selective blockage of α4β7 integrin, which binds to MADCAM1 in the gut wall.
- Largely used in UC.
79
What is the treatment of IgG4 disease?
Steroids +/- AZA
80
High serum level of what are predictors of severe disease in Crohn’s Disease?
ASCA, OmpC, Cbir-1
81
What do 6-MMP and 6-TG levels correspond with in Azathioprine use?
```
6-MMP = hepatotoxicity
6-TG = therapeutic / myelosuppression
```
82
When should allopurinol be used with thiopurines?
- Use in shunters, where 6-MMP/6-TG>11.
| - Allopurinol increases 6-TG and reduces 6-MMP
83
Name 4 adverse effects of PPIs
Hypomagnesaemia
Hypocalcaemia
Interstitial nephritis
Accelerated development of gastric atrophy and gastric cancer
84
What is first line Rx for Barrett’s oesophagus with high grade dysplasia?
Radiofrequency ablation
85
What does the oesophagus look like on endoscopy in eosinophilic oesophagitis?
White specks (eosinophilic exudates), “Corrugated iron”, longitudinal furrows, mucosal oedema and strictures
86
What is 1st, 2nd and 3rd line Rx for eosinophilic oesophagitis?
1. Elimination diet avoiding: wheat, milk, soy, nuts, eggs, and seafood
PPI => PPI + topical steroids => oral steroids if losing weight
87
Which intervention has the greatest effect on reducing mortality in variceal haemorrhage?
```
Antibiotics for 2 days
- norfloxacin (PO)
OR
- ceftriaxone (IV)
OR
- ciprofloxacin (IV)
```
88
How much bleeding is required to produce melaena?
150mL
89
In coeliac disease with rapid weight loss, what is the necessary next test?
Abdo/pelvis CT scan – to investigate for small bowel lymphoma
90
How is IgG4 disease diagnosed?
- Lymphoplasmacytic infiltrate on histopath
| - Positive staining for IgG4
91
What can be given to reduce risk of pancreatitis associated with ERCP?
PR indomethacin
92
What are the main characteristics of eosinophilic oesophagitis clinically and on biopsy?
- Dysphagia and food impaction
| - Eosophageal mucosal eosinophils > 15 per high power field
93
Which cytokines are predominantly involved in eosinophilic oesophagitis?
IL-5 and IL-13
94
What % of patients having endoscopy following food bolus have eosinophilic oesophagitis?
54%
95
What HPVG defines portal hypternsion?
HPVG > 5 mmHg
96
What should be used as secondary prophylaxis for spontaneous bacterial peritonitis?
Bactrim or norfloxacin
97
Granulomas are found in which type of IBD?
Crohn's Disease
98
What do NOD2 / CARD 15 confer in Crohn's Disease?
Worse survival, earlier onset, more small bowel involvement
99
What are the criteria for acute severe colitis in UC?
Bloody stool frequency > 6/day PLUS at least one of:
- Pulse > 90
- Temp > 37.8
- Hb < 105
- ESR > 30
100
Where is B12 absorbed?
Distal ileum
101
Which levels of Transferrin Sats and ferritin should prompt investigation for hereditary haemochormatosis?
TSAT > 45%
| Ferritin > 150 for females, > 200 for males
102
What findings on small bowel biopsy are supportive of a diagnosis of Whipple's Disease?
PAS-positive macrophages
103
What changes in B12 and folate levels are associated with small intestinal bacterial overgrowth?
Low B12, high folate
Luminal bacteria tend to consume cobalamin but produce folate
104
Which patients should receive pharmacological treatment in alcoholic hepatitis?
Maddrey score ≥ 32
Treat with prednisolone 40mg daily for 28 days
105
What is the mechanism of action of pentoxifylline?
Inhibition of TNF synthesis
106
What SAAG is highly specific for portal hypertension?
≥ 1.1 g/dL
107
In those with a low ascitic WCC and SAAG ≥ 1.1 g/dL, how can cirrhosis and CCF be differentiated?
Total protein ≥ 2.5g/L = cardiac ascites
| Total protein < 2.5g/L = cirrhotic ascites
108
What is TMPRSS6, where is it secreted from, and what is its function?
Protein secreted by hepatocytes, in response to iron.
| Suppresses hepcidin.
