Flashcards in Megaloblastic Anemias Deck (18):
What are some nutritional aspects of folate (probably not important)?
Intake is 200-250 micrograms a day, use about 100-150 a day, you store 10-12 and it is absorbed in the duodenum and jejunum
When is folate at increased demand?
During pregnancy (5-10 times more), lactation increases loss; When RBC turnover increases during hemolytic diseases; exfoliative dermatitis; and drugs
What are 3 things that impair Folic Acid absorption?
Resection of small intestine
What 3 demographics have poor dietary intake of folate?
Elderly, poor, alcoholics
What are the clinical features of megaloblastic anemias?
Insidious onset, mild jaundice, gossitis, angular stomatitis, weight loss, purpura
What is the treatment for Folate Deficiency? What must you be careful for when treating?
Give 1mg/day of folic acid orally; must be careful that the diagnosis is right, if not certain give both B12 and folate to avoid neuropathy of B12 getting worse while blood changes improve
What are our sources of B12 and how much do we need per day?
Animal products, milk, eggs, cheese; 1-2 micrograms per day, body stores are 2-3 mg's
What are the B12 deficiency gastric disorders?
Total gastrectomy, blind loop syndrome, and zollinger ellison syndrome
What is zollinger ellison syndrome?
Gastric producing tumors in the pancreas, gastric secretion of large amounts of HCl, acid inactivates pancreatic proteases and prevents transfer from Cbl from R binders to IF
What are the B12 intestinal disorders?
Ileal resection, Regional enteritis, Cbl malabsorption from hypthyroidism or drugs, tropical sprue
What are other causes of B12 deficiency?
Pancreatic insufficiency (lack of pancreatic juices resulting in failure to inhibit R binder/Cbl complex and transfer to IF) and Dietary-rare Vegans
What is neurologic disorder with B12 deficiency?
It happens early and involves parathesias of hands and feet, somulence and dementia, decreased vibritory and proprioception, loss of position sense. Late symptoms are spastic paralysis from demyelination (irreversible)
What is the history of Pernicious anemia?
1855 - Addison - invariably fatal "idiopathic anemia"
1926 - Munot and Murphy - effect of liver feeding
1929 - Castle - intrinsic factor
What is Pernicious Anemia?
An autoimmune disease with an insidious onset (like a ninja). Intrinsic factor secretion fails due to gastric mucosal atrophy. Onset after 40 yrs, prevalent in scandanavia
What is the Pathogenesis of Pernicious anemia?
Gastric atrophy - CD4+ T cells whose receptors recognize H+/K+-ATMPase
Antiparietal cell antibodies in 90% of PA and 60% of atrophic gastritis
Intrinsic factor antibodies found in 50-70% of PA
What are other AI diseases associated with PA? (7)
AI Thyroid Disorders
What is the Schilling test?
I) Drink .5 microCi of radioactive cyanocobalamin, start 24 hour urine collection, at 2 hrs = 1000 micrograms of IM B1, measure radioactivity in 24 hour uring collection
II) Give 60 mg of hog intrinsic factor with radioactive B12
III) repeat after 14 days of antibiotics