GI notes Flashcards
What is serology done for ulcerative colitis and results?
ANCA +ve, pANCA +ve, MPO ANCA negative
ASCA is not commonly tested
What can an AXR show in ulcerative colitis?
Absence of fecal matter (segmental manner of inflammation cannot hold the feces) hence presenting with diarrhea (doesnt necessarily need bowel prep due to diarrhea)
Dilatation of the bowel (worry about toxic megacolon): >9cm for caecum and >6cm transverse colon
Free gas in the peritoneum due to perforation as a complication of toxic megacolon
Indications in suspected ulcerative colitis for doing colonoscopy?
What is the bowel prep required for colonoscopy?
Is it always indicated in ulcerative colitis?
What are it’s complications?
To do biopsy to make histological dx and endoscopic dx + rule out concomitant infection
Bowel prep
* Low residue diet for 2 days
* Fluid diet 1 day before
* Split dose for bowel prep: needs to be drunk fast (not in sips) 1L in 1 hour
Requires sedatives (consious sedation not anaesthesia) and analgesics
RIsks: colonic perforation (1/1000) is higher as there is thinning of the mucosal wall (insufflation will cause rupture)
Bleeding from polypectomy
Vasovagal reaction: normally due to inadequate analgesics
In ulcerative colitis apart from colonoscopy what alternative can be used to visualize extent of lesion?
If safe can do flexible sigmoidoscopy and not under full sedation
Bowel will not be holding any faeces (inflamed mucosa cannot retain the faeces)
Ensure do not overinsufflate the bowel to avoid barotrauma causing perforation
What are the AE of azathioprine?
What genes needs to be checked?
It is an immunomodulator
- Myelosuppression
- Hepatotoxicity
- Pancreatitis
- Alopecia (totalis) will appear in a few months (rare)
Chinese prevalence of TPMT mutation is low (being phased out)
If TPMT mutation (low TPMT activity): higher 6TG and increased risk of myelosuppression
NUDT15 c.415C deficiency (increased chance of myelosuppression.
What method of administration of iron in ulcerative colitis and why?
2 reasons its IV
* Iron will cause mucosal toxicity (increased inflammatory cytokines) provoking ulcerative colitis
* Inflammatory state (IBD) causes increased hepcidin production which down regulates ferroportin 1 transporter in basolateral membrane of enterocytes thereby decreasing uptake of iron in the enterocytes
What are the 2 oppurtunistic infections linked with IBD that must be checked?
Clostridium difficile toxin by PCR (antibiotic associated)
CMV colitis (requires mucosal biopsy)
Compare the use of budesonide and prednisolone in IBD
Budesonide (synthetic steroid with high 1st pass effect (metabolized in intestine) so very little drug will escape into systemic circulation. Is an adv in UC as drug will stay in the intestine and not cause systemic toxicity.
But the effect is not as good as prednisolone (hence only used in mild cases)
Which liver enzymes are specific for hepatitis?
What enzymes for cholestatic pattern?
ALT is liver hepatic enzyme specific, AST is not used in some hospitals (not specific to liver)
What 2 parameters are used to monitor liver function in chronic failing liver?
Why dont use liver enzymes?
Bilirubin
INR
ALT initially will be increased due to parenchymal destruction. However after being released will go on a downward trend (not due to healing) due to dead hepatocytes until most are dead. No more ALT to release.
How can you tell from CBC and LFT of alcoholic liver disease?
AST>ALT (normally ALT is elevated in liver diseases)
Increased GGT
CBC
Macrocytosis: increased MCV
In hep B patient what are the 2 main reasons for increase in HBV DNA?
- Non compliance of drug
- Development of resistance strain (L180M, M204V)
What are the main antivirals used for HBV?
Lamivudine if prior to 2005 starting treatment (high level of resistance now)
Entecavir if starting treatment after 2005
If develops resistance –> transition to TAF (tenofovir) (less AE than TDF: nephrotoxicity and osteoporosis
What is ddx of fever and RUQ pain?
- hepatitis of any cause
- Acute cholangitis
- Acute cholecystitis
- RLZ pneumonia
- Amoebic liver abscess
What further Ix to do if liver abscess shows klebsiella pneumoniae?
- Consult eye for klebsiella pneumoniae endophthalmitis (urgent if has visual symptoms): 5-10% in klebsiella liver abscess patients esp DM
- Colonoscopy for underlying colonic neoplasm esp if elderly >60y with DM
WHat are types of autoimmune hepatitis?
Type 1 (>95%): anti smooth muscle ab (anti-Sm Ab), ANA and anti-actin ab (AAA)
Type 2: anti liver kidney microsomal (LKM) Ab and anti-liver cytosol type 1 Ab (ALC-1)
Type 3: characterized by anti-soluble liver antigen (SLA Ab. Usually seen in adults, increased IgG.
Clinical features for autoimmune hepatitis?
Chronic hepatitis (majority)
* Asymptoamtic: incidental finding of increased transaminases
* Insidious onset of fatigue, anorexia, nausea, abd pain, arthralgia, non specific erythematous MP rash
* Jaundice
Acute hepatitis
* Transaminases in thousands but -ve for all viral hep markers
* May even cause acute liver failure
Associated extrahepatic disorders
* AI thyroidits, T1DM, UC, sjogrens syndrome, RA, SLE, psoriasis
Ix for suspected autoimmune hepatitis?
LFT: increased AST/ALT up to 10-20x ULN in acute setting
Ig: increased total gamma globulins, with isolated IgG
AutoAb: ANA (sens), anti-Sm for type 1, Anti-LKM for type 2, anti SLA for type 3
Histology: periportal plasma infiltration +/-fibrosis
How to make a dx of autoimmune hepatitis?
- At least one elevated serum aminotransferases: AST/ALT >2xULN
- At least 1 positive lab test: increased IgG or total Ig, ANA, ASMA, anti-LKM1, anti SLA
Exclusion of ddx
* PBC: AMA can occur in AIH but is seldom the sole ab present
* Overlap syndrome: may have features of both AIH and PBC or both AIH and PSC
* Viral hepatitis and drug induced liver injury
Mx of autoimmune hepatitis?
Induction with high dose steroids to damp down inflammation
Maintenance with tapering steroids to decreased S/E
1st line therapy: prednisone and azathioprine
Induction: prednisone 15-30mg/d + AZA 50-100mg/d
Maintenance (lower dosage): prednisone 5-10mg/d + AZA 50-150mg/d
Monitoring during tx: AST/ALT, bilirubuin, gamma globulin, IgG q3-6mo for decreased disease activity.
Salvage therapy as other options: cyclospoirne, tacrolimus, MMF, rapamycin
What must be tested before giving azathioprine?
What are its SE?
TPMT deficiency: absolute CI to AZA therapy –> TPMT is needed to break down 6-MP into inactive metabolites –> life threatening myelotoxicity.
SE
* BM myelosuppression
* Cholestatic hepatitis and venoocclusive disease
* Pancreatitis
* Skin rash
* Severe nausea and abd pain
What is overlap syndromes of autoimmune liver disorders?
- AMA +ve autoimmune hepatitis: histological features of AIH, serological features of PBC, biochemical features of AIH e.g. increased transaminases
- AMA -ve PBC : clinical, biochemical and histological features of PBC. Serological features of AIH i.e. ANA+, ASMA+, AMA-
- AIH-PSC overlap: clinical and serological features of AIH with cholestatic features e.g. pruritisi, abnormal cholangiogram
Serology of PBC
Clinical features
AMA M2+
Clinical features: fatigue, pruritis, jaundice. skin findings: hyperpigmentation, cholesterol deposits: xanthomas, xanthelasmas. Excoriations and scratch marks. Fat malabsorption: steatorrhea, bone tenderness. Cirrhosis and portal hypertension in advanced stages.
Associated conditions: sjogren syndrome, scleroderma and thyroid disease. (not PSC which is bacterial immunology related to IBD)