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77 Cards in this Set
- Front
- Back
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What are the four general mechanisms of acquired underproduction anemia?
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Vitamin/nutrient deficiency, organ dysfunction, marrow failure, abnormal marrow microenvironment.
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What is the most common cause of iron deficiency anemia in developing countries?
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Hookworm infection leading to chronic intestinal blood loss.
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What is the most common cause of iron deficiency in males in the United States?
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GI blood loss.
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What is the order of changes in iron study values as iron deficiency progresses?
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Ferritin falls, TIBC rises, iron saturation falls, then anemia and microcytosis occur in later stages.
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What are two pulmonary conditions that can lead to iron accumulation in the lungs?
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Goodpasture syndrome and idiopathic pulmonary hemosiderosis. Both are mediated by macrophages.
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How much stored iron is used up in a normal pregnancy?
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1200 mg
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How does cow's milk contribute to iron deficiency anemia in infants?
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Low iron content, poor bioavailability, GI bleeding caused by toxic effect on mucosa from heat-labile proteins.
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Is spinach a good source of iron?
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No, mostly contains unabsorbable iron chelates.
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Which nutrient helps absorption of nonheme iron?
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Ascorbic acid (vitamin C)
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Celiac disease accounts for what portion of refractory iron deficiency anemia?
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20%
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In the elderly, what is a common cause of iron deficiency anemia not related to blood loss?
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Achlorhydria (30% prevalence)
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How does H. pylori infection contribute to iron deficiency anemia?
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Casuses occult bleeding, bacteria compete for iron, bacteria increase the pH which interferes with iron absorption.
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Pt's who do not respond to oral iron supplementation should be tested for what 3 conditions?
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H. pylori infection, celiac disease, autoimmune atrophic gastritis.
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Other than pallor, name 3 physical findings in iron deficiency anemia.
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Stomatitis, glossitis, koilonychia (pitting) of the nails
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What are the findings on peripheral smear in advanced iron deficiency anemia?
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anisopoikilocytosis, cigar or pencil shaped cells, thrombocytosis.
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What prevents serum iron level from being a good indicator of iron deficiency?
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Diurnal variation and fluctuations with dietary intake.
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What is the expected iron saturation level in iron deficiency anemia?
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>10%
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A ferritin level below what cutoff is diagnostic of iron deficiency?
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<15 mcg/L.
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Although ferritin increases as an acute-phase reactant, a level above what cutoff value would be unusual in iron deficiency?
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>100 mcg/L
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What two simple findings help differentiate between iron deficiency anemia and thalassemia?
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Iron deficiency demonstrates increased RDW, and target cells on peripheral smear point toward thalassemia.
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sTFR (soluble transferrin receptor) levels are increased or decreased in iron deficiency?
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Increased. sTFR is also increased with hemolysis, myelodysplasia and thalassemia.
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Iron tablets are best absorbed with or without food?
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without.
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What are some common foods and supplements/meds that can decrease iron absorption?
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Tea, antacids, grains, calcium.
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How can you test iron absorption?
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Give liquid ferrous sulfate to a fasting patient, check the level, wait two hours and check the level again, looking for at least a 100 mg/mL increase.
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Intramuscular iron has been associated with what type of malignancy?
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soft-tissue sarcoma
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What is the expected onset of reticulocytosis and hgb increase after beginning iron replacement therapy? How long until anemia resolves?
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Reticulocytosis in 4-7 days, Hgb increase in 1-2 weeks. Resolution usually occurs in 4-6 weeks.
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What are the typical findings on iron studies in anemia of chronic disease?
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Low to low normal serum iron and TIBC, normal or elevated ferritin
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Which cytokines figure prominently in the pathogenesis of AOCD?
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TNFa, IL-1, IL-6, interferons
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How do inflammatory cytokines contribute to anemia?
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reduce proliferation of erythroid precursors in response to EPO, decrease EPO production, reduce RBC survival.
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What effect does an increase in hepcidin have on iron metabolism?
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It keep iron where it is (i.e. in the intestinal lumen, in enterocytes and macrophages).
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Is there a role for EPO in AOCD?
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Yes, it the patient becomes symptomatic and EPO level is less than 500 IU/mL (100 mL in some studies). May take weeks, and iron needs to be replete.
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What are Howell-Jolly bodies ? Cabot Rings? What types of diseases or conditions are these associated with?
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nuclear remnants in RBCs, associated with megaloblastic anemia, postsplenectomy and hemolytic anemia.
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How can patients with megaloblastic anemia have low or normal MCV?
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co-existent iron deficiency or thalassemia.
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What are the expected findings on bone marrow examination in a patient with megaloblastic anemia?
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All lineages abnormal, possible ringed sideroblasts, decreased M:E ratio.
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How long does it take to become B12 (cobalamin) deficient from decreased dietary intake?
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years, due to pronounced enterohepatic circulation.
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At what age does the onset of pernicious anemia typically occur? Which blood type is it associated with?
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40's. Type A.
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Patients with pernicious anemia are at risk for developing which cancers?
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gastric carcinoma and carcinoid tumors.
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Can neurological deficits caused by cobalamin appear without anemia?
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yes
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Why should cobalamin levels always be checked prior to correcting folate deficiency?
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Folate repletion may correct anemia, masking ongoing B12 deficiency and allowing progression of neurologic deficits.
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What is the cutoff below which 95% of patients with cobalamin deficiency will show clinical signs?
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< 200 ng/L
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Levels of methylmalonic acid and homocysteine are helpful in diagnosing what?
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Borderline low B12 levels.
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What is the treatment for symptomatic cobalamin deficiency?
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1000 mcg IM daily for 2 weeks, weekly until the anemia resolves, then monthly. Blood counts normalize after 2-3 months. Oral replacement may suffice at 1,000-2,000 mcg daily.
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What is the main cause of folate deficiency?
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Inadequate dietary intake. Happens over the course of months.
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Folate deficiency affects which groups of people?
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Alcoholics, TPN, tea/toast diet elderly
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Which increases in folate deficiency, MMA or HCY?
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HCY.
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How is RBC folate level interpreted?
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Reflects folate stores over the last 120 days. RBC folate is decreased in B12 deficiency as well.
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Patient's with which chronic hematologic disorders should be on folate supplementation?
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Those with chronic hemolysis.
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Nitrous oxide has been associated with what hematologic abnormality and what neurologic abnormality?
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Acute megaloblastic anemia; psychosis.
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Name some drugs that can cause megaloblastic anemia.
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Zidovudine
5-FU methotrexate hydroxyurea azathioprine anticonvulsants H/K atp-ase inhibitors |
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Define sideroblast.
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an erythroid precursor with excess mitochondrial iron that surrounds or "rings" the nucleus.
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Name some causes of non-myelodysplastic sideroblastic anemia.
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Drugs (Isoniazid, chloramphenicol, cycloserine), toxins (alcohol), mutations in the ALA synthase gene, copper deficiency. DAAC acronym.
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Pt's with hereditary sideroblastic anemia related to ALA synthase may respond to supplementation with what?
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Pyridoxine.
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Starvation can lead to what bone marrow abnormalities?
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Normocytic normochromic anemia. In severe anorexia nervosa, a gelatinous substance secondary to necrosis can be seen.
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Sideroblastic anemia can be caused by deficiency of which nutrient?
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copper
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Excess intake of what nutrient can lead to copper deficiency?
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Zinc
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Which type of patients with anemia secondary to CKD tend to have anemia out of proportion to renal dysfunction?
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Diabetics.
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What endocrine disorder can contribute to the anemia of renal disease, and what is the mechanism?
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secondary hypoparathyroidism, which suppresses bone marrow and causes marrow fibrosis.
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What changes to RBCs occur in uremic patients?
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RBCs become less deformable and more susceptible to clearance by macrophages. Uremia also increases susceptibility to oxidative stress.
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What is another name for burr cells and what are they associated with?
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echinocytes, associated with uremia. Also commonly artifactual, or associated with bleeding ulcers or gastric cancer.
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What are the main adverse effects of ESA therapy in non-cancer patients?
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Seizure, HTN, thrombosis if Hgb rises too quickly or too high
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Describe the anemia of pituitary deficiency in terms of RBC indices, appearance on bone marrow examination, and 3 specific hormone mediators.
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Mild, normochromic, normocytic, hypoplastic marrow. Caused by deficiencies of hormones that modulate EPO production (cortisol, thyroid hormone, sex hormones)
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Describe the anemia of hypothyroidism in terms if RBC indices and mechanism.
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Caused by an absence of EPO-stimulated erythroid-colony formation. Normocytic, normochromic. Macrocytic anemia may be associated with autoimmune hypothyroidism.
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Describe the anemia of hypogonadism in terms of the degree of anemia.
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1-2 gm drop in Hgb. Respond to androgens, and androgens can be used in MDS and PMF.
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How does pancreatitis contribute to anemia?
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Impairs B12 absorption.
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What causes the decreased life span of RBCs in liver disease?
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Congestive splenomegaly, abnormal erythrocyte metabolism, alteration in RBC membrane lipids.
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What is the most common infectious cause of pure red cell aplasia and what is the mechanism?
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Parvovirus infection, which binds to the P antigen on RBC progenitors and destroys them.
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What is a characteristic finding on bone marrow of patients with Parvovirus infection?
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Giant pronormoblasts.
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What test is appropriate for Parvovirus infection in immunocompromised patients?
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PCR studies, as IgG and IgM may not be positive even with active infection.
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How is Parvovirus infection treated in immunocompromised patients?
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IVIg
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Other than parvovirus, what are two rare viral causes of pure red cell aplasia?
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Hepatitis and mononucleosis
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Which drugs are associated with red cell aplasia?
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Dilantin and other antiepileptics
chloramphenicol gold lindane dapsone INH rifampin sulfasalazine |
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PRCA has traditionally been associated with what type of tumor?
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Thymoma. Not as common as once thought. Aplasia responds variably to resection.
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PRCA can be associated with which hematologic malignancies? Which is most commonly underlying PRCA?
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LGL leukemia, CLL, lymphomas in general. LGL leukemia may be the most common cause. Collagen vascular disorders are also associated with PRCA.
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What peripheral smear findings are characteristic of leukoerythroblastosis?
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Teardrop reds, immature whites, large megakaryocytes, nucleated erythrocytes.
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What are possible explanations for otherwise unexplained anemia in the elderly?
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blunted hypoxia-driven EPO response, decreased sex steroids, decreased marrow cellularity and stem cells
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What malignancy is associated with sickle cell trait?
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Renal Medullary Carcinoma (RMC) is a highly malignant tumor that affects young black individuals with sickle cell trait. This exceptionally aggressive neoplasm typically presents at late clinical stage, virtually always associated with a lethal outcome, the average survival after surgery being less than four months
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In general terms, what difference in the CBC is seen between Caucasians and African Americans?
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hgb in AA runs about a gram lower
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