Nutritonal Anemias Flashcards
Macrocytic Anemia’s—MCV > 100 fL
Vitamin B12 (cobalamin, Cbl) deficiency Folate deficiency
Vitamin B12 deficiency
Meat & dairy products ONLY dietary sources of B12 for humans
Adequate absorption
Etiologies of B12 defiency
Pernicious anemia:
Chronic Atrophic Gastritis:
Clinical presentation
Macrocytic anemia
Hyperhomcysteinemia:
Neurologic changes (only seen in B12 deficiency):
Increased risk of osteoporosis:
Folate deficiency–Etiologies
Poor nutrition*—folate is found in meats, green leafy vegetables, nuts and fruit
Alcoholism
Infant’s who are primarily fed goat’s milk
When there are increased requirements:
Pregnancy (Folate prevents ? neural tube defects)
Patients w/ chronic hemolytic anemia
Drugs that interfere w/ folate metabolism— Trimethoprim, methotrexate, phenytoin
Folate Deficiency–Presentation
Macrocytic anemia and hyperhomocysteinemia
NO neurologic findings
Time frame for B12 and Folate Deficiency
Folate deficiency can occur within 4-5 months intake is diminished
B12 deficiency occurs after YEARS of inadequate intake because B12 stores in the body are so high
Diagnosing B12/Folate deficiency Suspect:
Presence of hypersegmented neutrophils/patient who has neurologic symptoms even if NOT anemic
Oval macrocytic RBCs on peripheral smear
Pancytopenia of uncertain cause
Unexplained neurologic signs: dementia, sensory ataxia, and parestheisias
Diagnosing B12/Folate deficiency Special Populations
Older adults Alcoholics Patients w/ malnutrition Strict vegans Patients who have undergone bariatric surgery and are not being compliant w/ their vitamins
Laboratory evaluation B12/Folate
Measure serum B12 level:
Measure serum folate level:
Metabolite testing
Laboratory evaluation B12/Folate Metabolic testing
Measure the metabolic intermediates: methymalonic acid and homocysteine
If these are ELEVATED then true B12 deficiency exists
If MMA is normal and homocysteine is increased folate deficiency is present
Diagnosing pernicious anemia
Measure antibodies to IF—specificity of 100%
Elevated gastrin/low pepsinogen—highly sensitive if antibodies negative
Schilling test NO LONGER used
Treatment of folate deficiency
Folic acid 1-5 mg po daily for 1-4 months or until complete hematologic recovery
Usually 1 mg a day is sufficient
Taking folic acid can partially reverse some of the hematologic effects of B12 deficiency
Treatment for B12 deficiency
Usually treated w/ IM or deep SQ injections of Cbl
Oral Cbl available—1-2 mg a day (200 x higher then the minimum daily requirement!
Also sublingual** and nasal spray preparations
Iron deficiency anemia—MCV < 80 fL
More than one quarter of the world’s population is anemic
½ of that burden is iron deficiency anemia
Most prevalent among preschool children and women
Absolute iron deficiency:
Iron stores in the bone marrow & in the liver/spleen are ABSENT
Serum ferritin is LOW
Absolute iron deficiency:
Etiologies
Poor dietary intake (foods, meds, celiac dz, atrophic gastritis)
Reduced iron absorption (gastric bypass)
Increased blood loss—Western world safest to assume cause is blood loss and search for that cause
Intravascular hemolysis
Congenital iron deficiency
Functional iron deficiency:
Insufficient availability of iron in the face of normal or increased iron stores
Functional iron deficiency:
Anemia of inflammation (anemia of chronic disease)
Hepcidin-induced block in the release of iron from the macrophage back into circulation
This makes iron less available for red cell production
Seen in patients w/ infection, inflammation, or malignancy
Functional iron deficiency treatment
erythropoiesis- stimulating agents
Available body iron stores may be unable to release iron rapidly enough to satisfy the increase brought about by the stimulating agent
Clinical manifestations for Iron deficiency
Asymptomatic** Weakness Fatigue Headache Irritability Exercise intolerance Glossal pain & reduced salivary flow (lead to dry mouth) May lead to exacerbation of co-morbidity (heart failure,angina(chest pain)) Pica Restless leg syndrome
Iron studies—normal values
Serum Iron (Fe) mcg/dL – 60 – 170
Ferritin ng/mL – 12 – 150 (females)/12 – 300 (males)
Transferrin/Total iron binding capacity (TIBC) microgm/dL –240 – 360*
Transferrin saturation (Fe/TIBC) % –15– 50
Rarely is it necessary to due a bone marrow biopsy for testing for stainable iron*
Differential diagnosis Iron deficiency
Thalassemia:
Anemia of chronic inflammation:
Sideroblastic Anemias:
Thalassemia:
May be + family hx
Serum Fe are normal to high
Hgb A2 level increased
RBC count is high
