Feb21 M1-IBD and Celiac Flashcards
**ulcerative colitis vs crohn’s: depth
UC = mucosal crohn's = transmural
**UC vs crohn’s pattern
UC = contiguous Crohn's = skips areas
**UC vs Crohn’s location
UC: rectum
Crohn’s: mouth to anus (rectum spared)
**UC vs Crohn’s rectum involvement
UC: rectum involved
Crohn’s: rectum spared
**UC vs Crohn’s ileum involvement
UC: none (or rarely backwash)
Crohn’s: common
**UC vs Crohn’s: presence of fistula or abcess
UC: no
Crohn’s: yes, can have fistula or abcess
**UC vs Crohn’s: granulomas
UC: NO granuloma
Crohn’s: granuloma in 10-30% cases
**UC vs Crohn’s: role of tobacco
UC: tobacco may prevent it?
Crohn’s: tobacco causes harm
**mnemonic for extraintestinal manifestations of IBD + meaning
C: cholangitis (PSC)
H: hematologic (anemia, amyloid)
E: eye
A: arthrisis (peripheral or axial)
T: thromboembolism
S: skin (nodosum, pyoderma gangrenosum, etc.)
(+ kidney stones, gallstones, osteomalacia, pericarditis)
(EXAM) granulomas in crohn’s or in UC
in crohn’s (10-30% of patients)
etiology of IBD
genetic predisposition (160 genes) + environmental triggers + immune system
cells of innate immune response
macrophages, neutrophils, natural killer cells
cells of adaptive immunity
B and T lymphocytes, dendritic cells
important gene in Crohn’s disease and epi
NOD2 (cytosolic R for pathogenic bacterial signals). increases risk of CD by 20-40%
main factors influencing microbiome composition
**diet, sanitation, hygiene, climate, vitamin D
how microbiome composition affects IBD
get diff type of IBD with diff microbiome
pathogenesis of IBD
- dendritic cells (APCs) sample luminal BACTERIA****
- APC present antigens to lymphocytes
- lymphocytes release proinflam cytokines (TNF alpha, ILs): IMBALANCE of proinflam molecules
- increase in adhesion molecules and vascular permeability
2 factors increasing risk of CD and IBD
- smoking (CD)
2. lifestyle like developed countries (IBD)
main symptom of IBD + important note
diarrhea. **primary etiology of diarrhea is infectious disease
tests for IBD
- CRP, calprotectin (inflam marker in stool), B12, anemia.
- endoscopy
CD is where
(upper gut rare)
small bowel alone
small bowel + colon
colon alone
what causes diarrhea in CD
inflammation
fibrostenotic lesion def in CD
inflamm caused scar tissues: areas of narrowing (distension, nausea, vomiting)
fistulas in CD what and why
link between bowel and other bowel or bladder, vagina, etc. bc CD is transmural
abscesses in what IBD
CD
CD features
diarrhea, abd pain, bleeding (no bleeding in IBS), strictures, fistulas, malabsorption
(IMPORTANT) 7 features of CD (MSNDBEE)
- mucosal erythema (edema)
- superficial ulcers
- nodularity from skip areas (cobblestoning)
- deep linear ulcers on axis
- bowel wall thickening (string sign)
- edematous mesentery (fat)
- extension of fissuring (fistula, abscesses, adhesions, etc.)
(IMPORTANT) histo feature of CD
mucosal inflam (crypt abscesses) and chronic mucosal damage, granulomas, ulceration, metaplasia
UC 3 stages
-proctitis: few bleeding
-less stools
-mucous
-constipation
left-sided colitis
pancolitis
most severe complication of UC
toxic megacolon (also called Crohn’s colitis): toxic damage to muscularis propria (tunica muscularis). dilated and gangrenous colon
UC 4 charact on endoscopy
- mucosal erythema
- broad ulceration
- pseudopolyps (regen mucosa)
- mucosal atrophy
meds for induction in IBD
ASA, CS, immunomodulator methotrexate, biologic meds (Abs, anti-TNF)
meds for maintenance in IBD
ASA, immunomodulators methotrexate and thiopurines, biological meds
only induction meds in IBD
CS
only maintenance meds IBD
thiopurines
IBD meds induction + maintenance
ASA, methotrexate, biological meds
(IMPORTANT) best meds in Crohn’s disease
biological meds (Ab, anti-TNF, etc.)
meds combo used in IBD + general plan
biological + immunosuppressant
usually: CS + maintenance
celiac disease other names
gluten sensitive enteropathy and nontropical sprue
celiac pathogenesis
T cell mediated immune disease triggered by gliadin (gluten protein)
2 important genetic factors in celiac
HLA DQ2, DQ8 gene loci on chroosome 6
how body rx with gliadin
TTG (tissue transglutaminase) modifies gliadin and it rxs with immune system
celiac on histo
CD8+ (cytotoxic) T cells infiltration, mucosal inflam, crypt hyperplasia, villous atrophy
3 types of celiac
- classic or typical
- atypica celiac sprue
- asymptomatic celiac
charact of typical celiac
steatorrhea, malabsorption, villous atrophy, mucosal lesions
atypical celiac charact
minor GI symptoms but many symptoms out of GI (osteoporosis, arthritis, anemia, neuro, ..)
asymptomatic silent celiac charact
gluten-sensitive enteropathy found after serology
latent celiac def
normal villous structure but positive marker for celiac (TTG positive)
refractory celiac def
very bad villous atrophy and not responding to 6 months gluten free diet
celiac diseases in order
healthy-latent-silent (asymptomatic)-atypical-typical
(IMPORTANT) celiac main symptom
nocturnal and early morning diarrhea (and also steatorrhea)
(IMPORTANT) skin condition associated with celiac
dermatitis herpetiformis (pruritic papules) (IgA deposits)
(IMPORTANT) gold standard for celiac dx
- IgA tTG (tissue transglutaminase) + order IgA
- if IgA deficient, order IgG TTG
celiac endoscopy features
scalloping, absent folds, fissures, mosaicism
(IMPORTANT) REAL way to dx celiac (bc IgA TTG not perfect)
biopsy
biopsy stages (done in D2) for celiac
0: preinfiltrative mucosa (can’t dx)
1: lymphocytes in LP
2. crypt hyperplasia
3. villous atrophy
4. total atrophy
(IMPORTANT) celiac treatment
gluten free diet
(IMPORTANT) celiac complications
increased risk of:
- lymphoma
- upper gut and SI malignancy
- ulcerative jejunoileitis
celiac vs gluten sensitivity
celiac = inflammatory sensitivity = allergy to gluten, no enteropathy
