Gastro-Intestinal Function Testing and GI Disease Flashcards

Question

What are biochemical tests for Pancreatitis

Answer 1

* Amylase * Lipase * Faecal Elastase

Answer 2

* Serum amylase \>3x upper limit of normal (ULN) strongly suggestive of pancreatitis, cut-off most often used in biochemistry labs * Concentrations begin to rise within hrs onset of pancreatic injury, and falls after 3-5 days * Urine amylase remains elevated several days after serum concentrations fall to normal, hence good test for late presentation * Serum amylase within ref range in up to 30% cases acute pancreatitis

Answer 3

* Peptic ulcer disease * Cholecystitis * Intestinal obstruction * Salivary gland disease * Pneumonia * Head injury * Renal failure * Diabetic ketoacidosis (DKA) * Anorexia nervosa

Answer 4

Benign cause of elevated serum amylase. Low urine amylase as large macro complex not filtered at glomerulus **Amylase-creatinine clearance:** * \<1% consistent with macroamylasaemia * \>5% consistent with AP

Answer 5

* Longer half life than amylase and higher activity hence better than amylase for late presentation patients * Similar sensitivity and specificity to amylase, but slightly more expensive * If elevated serum amylase but ?acute pancreatitis, can measure concurrent lipase

Answer 6

* Peptic ulcer disease * Mesenteric ischaemia * Renal failure * Bone fractures

Answer 7

Pancreatic Elastase-1 * Pancreas specific protease that passes unchanged through the intestine * Excellent test of severe pancreatic insufficiency but less sensitive in mild and moderate disease * Potential for false positives in watery stool samples * Also useful for monitoring CF patients * Non-invasive

Answer 8

* Autosomal recessive ~1/2500 N.European * Mutation in Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. CFTR protein regulates movement of Cl- and Na+/H2O across epithelial membranes – present in cells lining entire GI tract * Leads to multi organ dysfunction affecting Lungs, Pancreas, Liver, GI Tract * Most common mutation = ∆F508, ~1/30 heterozygous carriers

Answer 9

* **Pancreas:** Pancreatitis, Steatorrhea, Diabetes, Fat soluble vitamin deficiencies * **Lungs:** Bronchiectesis, Pneumonia , Respiratory failure, Hemoptypsis * **GI:** Meconium Ileus, Volvulus, Steatosis, Splenomegaly, Biliary cirrhosis * **Other:** Growth failure, Infertility, Delayed puberty, Osteoporosis

Answer 10

* Day 5-8 heelprick bloodspot * CF screening test = Immunoreactive Trypsinogen (IRT) * Screening test only, not 100% sensitive or specific hence will be false positives and false negatives * Confirmation by repeat IRT and DNA analysis of common CFTR mutation panel. Quality of bloodspot important

Answer 11

* No overlaying * Must fill collection circle * Minimise ‘milking’

Answer 12

Sweat Test is the gold standard. It is performed after 2 weeks of age and has requirements such as: * \>3Kg * Normally hydrated * No systemic illness * No eczema at sweat collection site * Not on corticosteroids

Answer 13

Sweat collection = Pilocarpine Iontophoresis * Measure sweat Cl- concentration on ISE, also measure Na+ concentration to ensure no discrepancy

Answer 14

Guidelines, sweat Cl- concentration cut-offs: * **\>60 mmol/L =** supports diagnosis of CF * **40-60 mmol/L =** equivocal, requires repeat (or 20-60 mmol/L if \<6 months age) * **\<40 mmol/L =** low probability for CF (or \<30 mmol/L if \<6 months age) 2 positive results on 2 separate days essentially diagnostic for CF, should be confirmed with DNA analysis

Answer 15

* GI malignancy * GI inflammation * Small bowel malabsorption * Pancreatic insufficiency * Motility disorders

Answer 16

* Passage of ≥3 loose or liquid stools per day for \>4 weeks, and/or daily stool weight \>200 g/day

Answer 17

**Organic vs Functional disease** * History \<3 months, Nocturnal/Continuous, Weight loss **Signs of Malabsorption** * Steatorrhea, Signs and symptoms of specific nutritional deficiencies **Signs of Inflammatory Disease** * Liquid stools, Blood/mucous, Abdominal pain

Answer 18

* **GI Inflammation:** Crohn’s, Ulcerative Colitis, Coeliac Disease, Malignancy * **Pancreatic Disease:** Pancreatitis, Malignancy, Cystic Fibrosis * **Endocrine:** Hyperthyroidism, Hypoparathyroidism, Diabetes Mellitus, Addison’s, VIPoma, Gastrinoma, Carcinoid * **Others:** Lactose Intolerance, Drugs, Alcohol, Laxative Abuse

Answer 19

* **GI Inflammation:** Test with Faecal Calprotectin, Anti-tTG/Endomysial Ab, Tumour Marks FOB/FIT * **Pancreatic Disease:** Test with Amylase, Lipase, Faecal Elastase, Tumour Markers IRT/Sweat Test * **Endocrine:** Test with TFTs, Bone/PTH, OGTT/HbA1c, Cortisol/SST, Gut hormones, 5HIAA * **Others:** Test with Faecal Reducing Substances, Urine Laxative Screen, GGT/CDT

Answer 20

* Enhanced Liver Fibrosis (ELF) Test * Used a screening test in primary care population to reduce patients referred for needle biopsy of liver

Answer 21

* Hyaluronic acid (HA) * Procollagen III amino terminal peptide (PIIINP) * Tissue inhibitor of metalloproteinase 1 (TIMP-1)

Answer 22

* Morbidity & mortality * Samples very small portion of liver * Costly & time consuming * Operator variability / error rate * Cannot perform repeat biopsy at short intervals

Answer 23

* Identify patients at early stages liver fibrosis before progressing to cirrhosis * Cost effective and safer compared to biopsy * Single blood test no patient preparation required * As good as Fibroscan

Answer 24

* Screening test, therefore, not 100% sensitive or specific * False positives and false negatives * Currently only available on Siemens analysers

Answer 25

* **Radiology:** Ultrasound, CT, MRI * **Microbiology/Virology** * **Immunology:** PBC/PSC * **Histology** * **Breath test:** Bacterial overgrowth

Gastro-Intestinal Function Testing and GI Disease Flashcards

(49 cards)