Anemias

Question 1

Iron deficiency anemia

Answer 1

microytic anemia; decreased iron absorption or intake, increase requirement, excessive blood loss; faitgue, pica, glossitis, nail abnormalities, Pummer-Vinson syndrome; lower serum iron, ferritin, % transferring sat., higher TIBC

Question 2

Anemia of chronic disease

Answer 2

microcytic or normocytic; Inflammation increases hepcidin, which binds to ferroportin and prevents absorption of iron in the enterocytes and release of iron from macrophages and hepatocytes; higher ferritin, lower serum iron, TIBC

Question 3

Functional iron deficiency

Answer 3

conditions with increased erythropoiesis (e.g. after EPO administration); adequate iron in body, but it cannot be released quickly enough from storage to support the increased erythropoiesis; intravenous iron may be required.

Question 4

Sideroblastic anemia

Answer 4

microytic anemia; heretidary = X-linked ALA synthase, treat with PLP; acquired = alcohol, lead poisoning; smear shows ringed sideroblasts (has granules of iron accumulated in the miochondria; higher serum iron, ferritin

Question 5

Lead poisoning

Answer 5

sideroblastic anemia (microcytic); inhibits ferrochelatase and ALA dehydratase; inhibit rRNA degradation -> aggregates show basophilic stippling; L (lead lines on gingivae and metaphyses) E (encephalopathy and erythrocyte basophilic stippling) A (abdominal colic and sideroblastic anemia) D (Drops, wrist and foot; dimercaprol, EDTA)

Question 6

Alpha thalassemia

Answer 6

microcytic anemia; alpha-globin gene deletion; 4 allele deletion - hydrops fetalis; 3 allele deletion - HbH disease; 2 and 1 alelle deletion - less clinically severe anemia

Question 7

Beta thalassemia

Answer 7

microcytic anemia; beta-globin point mutations; homozogotes lacking B chain needs blood transfusion to maintain Hb levels

Question 8

Acquired Hemachromatosis

Answer 8

buildup of free iron cause organ damage; acquired = repeated transfusions

Question 9

Hereditary Hemachromatoses

Answer 9

buildup of free iron cause organ damage; mutation in hereditary hemochromatosis protein causes low hepicidin production -> intestinal absorption of iron continues in spite of adequate iron stores

Question 10

Megaloblastic anemia features

Answer 10

Impaired DNA synthesis, nuclear:cytoplasmic asynchrony, hypersegmented neutrohphils, ineffective hematopoiesis affecting all cell lines, pancytopenia, increased retics, MCV, oval macrocyte

Question 11

Folate deficiency

Answer 11

megaloblastic anemia; 3 months to develop from malnutrition, anti-folates, increased requirements; jaundice, glossitis, neural tube defects, increased homocysteine but normal methylmalonic acid

Question 12

Vitamin B12 (cobalamin) deficiency

Answer 12

megaloblastic anemia; 3-4 years to develop from veganism, malabsorption, pernicious anemia, tapeworm; neurological symptoms because involved in myelin synthesis, increased homocysteine, methylmalonic acid

Question 13

Schiling test

Answer 13

tests for pernicious anemia; give B12 i.m. to sop any empty B12 binding sites, give oral radioactive B12 -> little radioactivity in urine = no absorption; stage 2 give radioactive B12 with intrinsic factor -> if radioactivity in urine = pernicious anemia, if not another malabsorption problem

Question 14

Orotic aciduria

Answer 14

megaloblastic anemia; cannot convert orotic acid to UMP thus orotic acid in urine; no hyperammonemia (vs OTC deficiency); treat with UMP

Question 15

Other causes of megaloblastic anemia

Answer 15

hematological malignancies (myelodysplastic syndrome), congenital dyserythropoietic anemia, drugs

Question 16

Non-megaloblastic macrocytic anemia

Answer 16

macrocytic anemia where DNA synthesis is unimpaired and there are no hypersegmented neutrophils; caused by alcoholism, liver disease, hypothyroidism, reticulocytosis

Question 17

Acute hemorrhage

Answer 17

normocytic, BM responding anemia; increased EPO and retics

Question 18

Evidence of RBC regeneration

Answer 18

in BM, decreased myeloid/erythroid ratio; in peripheral blood, increased retics, nRBCs, increased MCV

Question 19

Intravascular hemolysis

Answer 19

hemolysis in blood vessels -> decreased haptoglobin, hemoglobinuria, increased LDH, schistocytes, increased retics

Question 20

Extravascular hemolysis

Answer 20

hemolysis in spleen by macrophages -> mild decrease haptoglobin, spherocytes

Question 21

Intrinsic hemolysis

Answer 21

result of a defect in the RBCs; includes defects in membrane proteins, enzymes, or hemoglobin.

Question 22

Extrinsic hemolysis

Answer 22

reasons external to the RBCs; includes immune and non-immune causes

Question 23

Hereditary spherocytosis

Answer 23

intrinsic hemolytic normocytic anemia; mutation in membrane protein resulting in vertical defect that disrupts the linkage between the transmembrane and cytoskeletal proteins; results in loss of membrane -> spherocytes, trapped in spleen, extravascular hemolysis

Question 24

Paroxysmal nocturnal hemoglobinuria

Answer 24

intrinisic hemolytic normocytic anemia; unable to synthesize GPI-anchor on cell membrane; absence of GPI-linked proteins, CD55 and CD59, results in lysis by complement; triad is hemolytic anemia, pancytopenia, venous thrombosis; treat with eculizumab (anti-C5)

Question 25

Glucose-6-phosphate dehydrogenase (G6PD) deficiency

Answer 25

intrinsic hemolytic normocytic anemia; mutation does not allow reduction of glutathione making the RBC susceptible to oxidant stress (sulfa drugs, antimalarials, infections, fava beans); Hb oxided to methemoglobin -> precipiates as Heinz bodies -> macrophages try to get rid -> Bite cells

Question 26

Pyruvate kinase deficiency

Answer 26

intrinisic hemolytic normocytic anemia; less ATP, rigid RBCs -> Burr cells

Question 27

Autoimmune hemolytic anemia

Answer 27

Extrinsic hemolytic normocytic anemia; Warm (IgG) - SLE, CLL; Cold (IgM) - M. pneumonia, Mononucleosis

Question 28

Microangiopathic hemolytic anemia

Answer 28

Extrinsic hemolytic normocytic anemia; RBCs are sheared as they pass through obstructed or narrowed vessel lamina -> schistocytes; seen in DIC, TTP/HUS, SLE, and malignant hypertension

Question 29

Macroangiopathic hemolytic anemia

Answer 29

Extrinsic hemolytic normocytic anemia; mechanical destruction, prosthetic heart valves, aortic stenosis -> schistocytes

Question 30

Infections (anemia)

Answer 30

Extrinsic hemolytic normocytic anemia; malaria, Babesia

Question 31

Acquired aplastic anemia

Answer 31

Nonhemolytic, normocytic anemia; autoimmune T-cell mediated response against hematopoietic stem cells leads to pancytopenia, hypocellular bone marrow; caused by radidation, drugs, viral agents, idiopathic

Question 32

Fanconi anemia

Answer 32

inherited aplastic anemia; mutation in DNA repair genes; skin pigmentation, short stature

Question 33

Dyskeratosis congenita

Answer 33

inherited aplastic anemia; mutation in telomerase complex genes; skin pigmentation, nail dystrophy, mucosal leukoplakia

Question 34

Pure red cell aplasia

Answer 34

Bone marrow: only erythroid precursors decreased; WBCs and PLTs normal; Diamond-Blackfan anemia (mutation in ribosomal protein genes)

Question 35

Myelophthisic

Answer 35

Infiltration and proliferation of abnormal cells in bone marrow (e.g., leukemia, fibrosis) -> tear drop RBCs because of extramedullary hematopoiesis

Question 36

Anemia of chronic kidney disease

Answer 36

Decreased erythropoietin production by the kidney; treat with EPO

Question 37

Polycythemia vera

Answer 37

increased hematocrit, > 95% have JAK2 mutation, thus low EPO but still increased RBCs, WBCs, PLTs; Secondary polycythemia caused by increased EPO; Relative polycythemia is a decreased plasma volume