Term
| Name genes associated w/ IBD and the role of the most famous one... |
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Definition
| Genetic hot spots identified like IBD1 a gene on Ch. 16 identified as NOD2, an intracellular macrophage receptor aids in clearing bacteria from the tissue (receptor for bacterial antigen). Mutations in NOD2 are associated with ileal Crohn's disease. Identified by Dr Gabriel Nunẽz and colleagues at UM! Other recently identified disease susceptibility genes include IL 23 which is important for maturation of a subset of T cells (emerging as important factor in IBD) |
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Term
| How does smoking affect IBD? |
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Definition
| Smoking affects IBD: worsens Crohn’s, improves UC (often present after quitting) |
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Term
| What is the role of Peyer's patches in IBD? |
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Definition
| Peyer's patches are key points of contact between the mucosal immune system and the luminal environment. Most prevalent in terminal ileum (b/c lots of bacteria there). Specialized M cells “sample” the luminal contents, and present them to macrophages/dendritic cells in the lymphoid nodule below the surface, to look for pathogenic bacteria. This recognition may be the first step in Crohn’s. |
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Term
| What is the role of Th1 subset and its target? |
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Definition
| activated cells express primarily a anti-inflammatory set of cytokines including IL-4, IL-5 and IL-13, These cells are especially important in immunity against parasites. |
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Term
| What is the role of Th1 subset and its target? |
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Definition
| activated cells express primarily a pro-inflammatory set of cytokines including INFgamma and TNFalpha. These cells are important in immune response to all pathogens but particularly intracellular bacteria. |
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Term
| What is the role of Th17 subset and its target? |
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Definition
| activated cells express IL-17 and GCSF. These cells are especially important in immunity against extracellular bacteria. IL-23, one of the Crohn’s disease susceptibility genes, is important for activation and maturation of Th17 cells. (defect in Crohn’s results in incorrect response to pathogens) |
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Term
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Definition
| chronic intestinal inflammation in IBD results from an abnormal immune response to a luminal agent (possibly a bacterial product or some other commonly encountered luminal agent) in a genetically susceptible host. |
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Term
| Presenting symptoms of IBD |
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Definition
o Abdominal pain (inflamed bowel pain)
o Diarrhea: most common presenting sign
o Weight loss: malabsorption, N/V, anorexia, obstructions etc. (i.e. many reasons)
o Extra intestinal manifestations
arthritis
skin involvement (pyoderma gangranosum, erythema nodosum)
eye inflammation (uveitis, conjunctivitis)
hepatobiliary abnormalities
o Rectal bleeding (ulcers) |
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Term
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Definition
Proctitis – involves only the rectum. Patients have frequency, urgency, tenesmus (feeling like you have to have a bowel movement but can’t) and bleeding due to the proximity of the inflammation to the anal control mechanisms. Have trouble telling difference between flatus and stool. Patients do not usually have extraintestinal manifestations and are not usually systemically ill. May not need colectomy.
Left sided colitis – patients may have impressive diarrhea and more systemic symptoms such as fever, elevated WBC, arthritis, skin manifestations.
Pancolitis - patients tend to be the most systemically ill (high sed rates, high CRPs) with lots of diarrhea, serious complications, potential for toxic megacolon. |
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Term
| What is the endoscopic appearance in normal, mild, moderate, and severe UC? |
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Definition
diagnostic, because the disease only affects mucosa so it is easy to see
Normal – nice Haustral folds, shiny, see vessels under mucosa
Mild – granular mucosa with loss of vascularity, mucosa is thickened, edematous
Moderate – above plus friability (bleeds easily when bumped with the scope)
Severe – above plus ulcerations and pseudopolyps |
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Term
| Conditions that mimic UC: |
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Definition
| infections, radiation, antibiotic associated, ischemic bowel |
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Term
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Definition
BLEEDING
Toxic megacolon
Perforation – stretching and inflammation make the wall weaker
Cancer – chronic inflammation predisposes to cancer
Stricture formation – occurs with healing after inflammation, and more in mucosal layer but in Crohn’s it’s Transmural! |
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Term
| Extraintestinal manifestations of UC: |
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Definition
Skin – erythema nodosum, pyoderma gangranosum
Eye – conjunctivitis, uveitis
Joints – sacroilitis, peripheral arthritis
Liver/biliary tree – sclerosing cholangitis |
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Term
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Definition
can occur anywhere from mouth to anus, though most common in terminal ileum and right colon
Terminal ileum
Terminal ileum and colon – most common
Colon only – can be hard to tell from ulcerative colitis
Disease elsewhere in the small intestinal
Rare sites: esophagus, stomach, duodenum (i.e. upper GI) |
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Term
| Natural history of Crohn's |
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Definition
Chronic inflammation of all layers
Stricturing disease - fixed luminal narrowing due to smooth muscle hypertrophy and collagen deposition obstruction with dilation proximally
• Easy to obstruct the small bowel because of narrow lumen
Fistulizing disease - intraabdominal or perianal fistulas, inflammatory masses, or abscesses. Deep burrowing ulcers fistulas (e.g. between bowel, rectum-bladder, rectum-vaginal)
Perianal fistulae/abscess
Microperforation (appendicitis-like) |
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Term
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Definition
| discrete ulcer, cobblestone, stricture |
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Term
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Definition
| stricture, abscess, fistula, perforation, cancer (risk is not as high as UC), diarrhea and malabsorption |
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Term
| What blood test differentiates Crohn's from UC |
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Definition
| Crohn's is ASCA+/ANCA-; UC is opposite |
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Term
| In UC, is there more pain or is there more diarrhea? |
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Definition
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Term
| Name the goals that involve the immune system in Crohn's: |
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Definition
o Alter the natural history of the disease: goal is to drive a more favorable immune response and restore balance of pro- to anti-inflammatory factors
Immunomodulination
• Suppress helper T Cell function
• Inhibit action of key cytokines (ex: TNF-alpha)
• Support a healthy epithelial barrier
Alter luminal contents: antibiotics, probiotics |
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Term
| Sulfasalazine/Mesalamine derivatives: mechanism and limitations |
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Definition
: = sulfapyridine + 5-aminosalicysilic acid drugs: not very potent but very safe and effective for mild to moderate disease.
Have two components: sulfapyridine acts as a carrier to get to small intestine, while ASA has anti-inflammatory action => Mechanism: inhibits lipoxygenase pathway, O2 scavenger, inhib IL-2 release
Limitations: we need derivatives due to sulfa allergies |
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Term
| CCS role of treatment, limitations, and newer forms advantage? |
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Definition
(mainstay, but avoid long-term treament)
Work to decrease inflammation in short term, but SEs limit long term use
New high first pass steroids have high first pass met in liver lower systemic blood levels reduces systemic side effect while maintaining high luminal concentrations
Oral, rectal, parenteral forms
SE: HPA axis suppression, weight gain, diabetes, osteoporosis, infection risk, cataracts, osteonecrosis |
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Term
| Immunomodulators: (2) azathioprine and 6-MP - use, mech, and limitations |
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Definition
• azathioprine/6-mercaptopurine (6-MP) – very commonly used purine analogs with potent anti-inflammatory effects on immune system (inhibit nucleoside biosynthesis, inhibit T cell activation), used for maintenance of remission but have SES of pancreatitis, neutropenia, teratogenicity, malignancy
Also may use Methotrexate in new paradigm |
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Term
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Definition
• Anti-TNF therapy (infliximab, adalimumab but you get loss of response w/ antibody development, etanercept)
o Can exacerbate other diseases – infection risk (e.g. TB, HBV)
o But highest promise to alter course |
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Term
| Surgery options for UC and Crohn's |
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Definition
UC - J pouch
Crohn's - stricturoplasty |
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