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Heme/Onc - Vitamin B12 deficiency, Folate deficiency Flashcards

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4658012820Vitamin B12 deficiency what type of anemia?macrocytic0
4658012821vitamin B12 deficiency B12 plays important role in - incidence increases with-NEURO function age1
4658012822B12 in what foods? (only source)animal proteins dairy eggs shellfish fish2
4658012823cobalamin absorption depends onadequate diet intake acid-pepsin in stomach pancreatic proteases gastric secretion of intrinsic factor ileum w/ functional cobalamin-IF receptors3
4658012824causes of vitamin B12 deficiencyinadequate diet (usually not the issue) malabsorption - *pernicious anemia* & others *other* H. pylori chronic pancreatitis zollinger-ellison syndrome HIV hereditary factors drugs4
4658012825pernicious anemiaautoimmune destruction of parietal cells --> dec IF ===> malabsorption of B12 may be with other autoimmune d/o - thyroid, addison's vitiligo5
4658012826other causes of malabsorption of B12gastrectomy/gastritis (total/partial, roux-en-Y) ileal resection (abs in terminal ileum) crohn's dz (ileal) fish tapeworm6
4658012827hereditary B12 deficiencytranscobalamin deficiency usually presents within few weeks of birth7
4658012828drugs that cause B12 deficiencymetformin (put on Ca2+ to avoid) PPIs8
4658012829vit B12 def - clinical manifestationsgeneral - glossitis NEURO - peripheral neuropathy (symmetrical, LE) ataxia (vibration, position), weakness PSYCH - irritability, depression, personality changes, memory impairment, dementia skeletal - osteoporosis9
4658012830vit B12 def - diagnosisCBC peripheral blood smear *vitamin B12* *methylmalonic acid* *homocysteine lvl*10
4658012831vit B12 def CBC: mcv peripheral blood smear:CBC: low Hgb, MCV >100, RDW inc (sizes vary) smear: macroovalocytes, lg oval erythrocytes, hypersegmented neutrophils11
4658012832vitamin B12 normal =>30012
4658012833borderline result = if borderline results... what should you do?200-300 order homocysteine lvl methylmalonic acid lvl13
4658012834low = B12 value is consistent with deficiency<20014
4658012835falsely low B12folate deficiency multiple myeloma pregnancy15
4658012836falsely normal B12chronic liver dz myeloproliferative disorders chronic renal dz16
4658012837if you suspect B12 def, what should also be checked for?folate deficiency17
4658012838B12 def methylmalonic acid = homocysteine lvl =increased increased18
4658012839which his increased with BOTH folate and B12 deficiency?homocystiene lvl19
4658012840increased methylmalonic acid can also be found in patients withchronic renal insufficiency20
4658012841methylmalonic acid & homocysteine lvls both normal = both increased =vit B12 and folate deficiency ruled out B12 deficiency confirmed21
4658012842autoimmune destruction of gastric parietal cellspernicious anemia22
4658012843pernicious anemia = increased risk ofgastric carcinoma 3x higher EGD to look for signs of cancer23
4658012844pernicious anemia diagnosisshilling test anti-intrinsic factor antibodies anti-parietal cell antibodies24
4658012845HIGHLY confirmatory for diagnosisanti-IF antibodies***25
4658012846shilling testrarely used today distinguishes IF related malabsorption (location)26
4658012847vit B12 deficiency treatmenttx underlying cause if possible vitamin B12 - IM or oral27
4658012848B12 IM dose1 mg IM QD x 7 days, then 1 mg IM weekly x 4 weeks, then 1 mg monthly28
4658012849oral B121000-2000 mcg/day29
4658012850hemoglobin normalizes by2 months30
4658012851neuro sx improve over3 months max @ 6-12 mo31
4658012852B12 screeningno guidelines base on history, PE, risk factors (i.e. bypass)32
4658012853where is folate found?animal products leafy veggies fruits cereal & grains nuts33
4658012854folate deficiency most commonly due tomalnutrition poor diet +/or alcoholism (alcohol inhibits abs)34
4658012855where is folate stored?liver stores last 2-4 months35
4658012856drugs that can cause folate deficiencymethotrexate phenytoin trimethoprim36
4658012857intestinal malabsorptioncrohn's sprue37
4658012858increased folate requirementsinflammatory dz - psoriasis exfoliative dermatitis RA crohn's38
4658012859folate deficiency clinical manifestationsweakness glossitis fatigue weight loss NO neuro sx39
4658012860folate deficiency diagnosisfolate level red cell folate homocysteine level40
4658012861folate level: red cell folate: homocysteine level:folate level: inc or dec (short-term reflection) **red cell folate: decreased homocysteine level: increased (methylmelonic acid NOT)41
4658012862what is most reliable indicator of folate lvl?red cell folate42
4658012863folate deficiency treatmenttx underlying folic acid43
4658012864folic acid dose1 mg/day 1-4 mo. or until complete hematologic recovery44
4658012865IMPORTANT: rule out this BEFORE treating for folic acidB12 deficiency45

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