Hematology 2 Final Exam PDF

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All notes from first class to last, a comprehensive review for the final examination ...

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Normal absorption of iron o Erythrocytes store the most iron in the body (2500 mg) o Iron comes from diet o Converted to ferrous condition in stomach  can only absorb ferrous iron o iron absorbed in the duodenum and jejunum o

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 gastric bypass – issue because can prevent iron absorption females absorb 12 % and males 6%

 Diet will not greatly increase absorption  Max iron absorb is 20% o Iron in mucosal membrane oxidized to ferric and binds with apo protein  this is called ferritin o Transferrin- moves ferritin in circulation to bone marrow Iron deficiency anemia – most common o Anemia – decreased red cells (affects hgb) o Causes:  Increased need: women during child bearing ages, pregnancy, childhood  Excessive loss  Males: GI bleed  Females: menstrual bleeding; GI Bleeding (post-menopausal) o Lab findings: Serum – decreased % Saturation – decreased Total iron binding capacity – increased  Increased because trying to “dock” more transferrin  Serum ferritin (reflects iron stores) – decreased o Soluble transferrin receptor (sTFR)  Receptor for transferrin (membrane-bound protein)  Fragment of TfR finds way into serum  Reflects receptor production  Transferrin bound iron decreases = increases sTFR production = increase in sTFR concentration o Three stages of IDA  Iron depletion of iron stores [marrow: Prussian blue negative or decreased]  Iron deficiency: decreased serum iron and decreased transferrin saturation  IDA (chronic): decreased H&H, N/N anemia to micro/hypo anemia  MCHC and MCV decreased o Treatment – correct GI bleed and oral iron supplements  Oral iron therapy is monitored by reticulocyte count  1-2 weeks: peak reticulocytes  3-4 weeks: significant increase in hgb  2-4 months: hgb levels normal Reticulocyte count- methylene blue stain o Precipitates RNA to visualize retics. o Assess erythropoietic activity of bone marrow o Retics. Spend 2 days in bone marrow and 1 day in circulation before maturation o Reference range: 0.5-1.5 %  (# retic./1000 red cells) *100 o Increased count indicates taking iron supplements and bone marrow is responding Disorders of iron excess o Slow accumulation of excess quantities of iron o Hemochromatosis (iron accumulates in parenchymal cells)  Parenchymal – functioning cells  Males to female 5:1  Presents in 50’s  Skin hyperpigmentation  Affects vital organs (heart, pancreas, liver)   

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Treatment:  Removal of 500 mL of blood removes 200 mg of iron (therapeutic phlebotomy)  Life span is normal in patients without cirrhosis  Treatments may improve diabetes (bronze diabetes), and cardiac function Hemosiderosis- accumulation in reticular endothelial system  Does not cause organ damage  Cause: transfusions (people with sickle cell anemia are prone) Sideroblastic anemia – defective synthesis of heme resulting in iron overload  Stops at any path in heme synthesis  Dimorphic smear- hypo/norm –chromic cells (nonspecific to disease)  Ringed sideroblasts – specific to disease  Erythroblast with iron ring  Normally 30-50% of late erythroblasts have 1-2 granules of iron (Prussian blue stain)  Iron inclusions form a ring around nucleus  Classification (different types)  Hereditary (sex- linked) male o Treated with vitamin B6 to move pathway right o Not major issue 

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Acquired o Idiopathic – myelodysplastic syndrome – refracting anemia with ringed sideroblast o Secondary –

Drug (lead poisoning) – water, lead based paint  Stops pathway in three places  Causes mental retardation, hearing impairment and growth impairment  Disease (cancer) Globin chain disorder anemias – globin chains two alpha (141 aa) and two beta (146 aa) o Hemoglobinopathies- amino acid substitution in globin chain 

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Sickle cell anemia (Hb SS)  Crescent shaped RBCs  Beta chain sixth position switched to valine instead of glutamic acid  Substitution causes alignment of alpha and beta chains (instead of repulsion) o Microfilaments align in parallel chains  Three types of crises o Vaso – occlusive (painful): tissue hypoxia and infarction  Smear: polychromatophilia, target cells, sickles, nucleated reds, inclusions  Howell-jolly (1 cluster of RNA) and pappenheimer bodies (2-3 clusters of iron)  Peaks in January, February and September – decreased oxygen  Sickle cell RBCs clog in microvasculature

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Solubility test- screening test o 2 tubes with RBCs o Reagent lyses and reduces oxygen tension o Hgb S polymerizes in the deoxygenated state and forms precipitate (cloudy/turbid) o Reported as: tube was +/- for sickling hgb; is not used to diagnose Hemoglobin electrophoresis- confirmatory test o Separates different hgb’s by electrical charge o Cellulose acetate matrix o Basic pH 8.4-8.6 o Hgb A1 = A (accelerates fastest) and furthest from Application point o Hgb S = S (moves slower)

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o Hgb C = C (lysine sub. Instead of valine; slowest) Disease o Hgb S mainly

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o No Hgb A1 o Hgb A2 is normal o Hgb F is 2-10% (slight elevation)  Treatment o Preventative therapy: reduce conditions that cause vaso-occlusion i.e dehydration and infection o Pharmacological agents  Hydroxyurea- decreases painful crises incidence  Reduces intracellular sickling  Increases level of Hgb F (not as good as A, better than S) o Bone marrow transplantation – last resort  Newborn screening- in place of waiting for symptoms to arrive; often ended in death due to sepsis o Penicillin prophylaxis reduce risk of serious infection o Screen every newborn Sickle cell trait (HB SA)  Few target cells on smear  Sickle solubility test positive  Hgb electrophoresis o Hgb S (20-40%) o Hgb A1 at least 50% - no disease present because of this o Hgb A2 and F are normal  when two cell traits mate = child 25% sickle cell, 50% trait, 25% no trait Hemoglobin C disease  1 amino acid substitution (beta; sixth; glutamic acid to lysine)  Mild chronic anemia with abdominal pain  Target cells 50-100%  Hgb electrophoresis - hgb C mainly o Hgb C and A2 similar place of migration  Hgb C-crystals on smear o Only seen if spleen is not functional Hemoglobin SC disease  Trait Hgb C – one copy of valine and one copy lysine mutation  Severity between SCT and SCA with anemia, joint, abdominal and skeletal pain o Due to sickle cell vaso-occlusion  Hgb electrophoresis – S and C hgb  Smear – target cells, intracellular crystals (Washington monument) o Parallel sides, pointed top  Solubility test positive Hemoglobin D disease  Beta chain substitution at 121st position (glutamic acid to glycine)  Migrates at same position as Hgb S o Differentiate with solubility test

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o Positive with S disease o Negative with D disease Citrate agar; pH 6.0- 6.2 (electrophoresis) o S moves to the left o D moves to the right

 Thalassemia- decreased synthesis of globin chains  Beta thalassemia- devastating  Ancestry: Mediterranean and Asian  Major: o B0/B0, B+/B+, B+/B0, o 0= extremely slow synthesis; almost none += reduced synthesis Electrophoresis  Hgb A1 Hgb A1 (always)  Hgb F and A2 are normal or slightly increased o o

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Alpha thalassemia – varying severity results from reduced or absent alpha chain synthesis affecting the two pairs of alpha globin genes (one pair in each chromosome 16)  Four loci in chromosome 16  Four mutations (Bart hgb)= 4 gamma chains; die in utero  3 mutant genes = hgb H disease o Hgb H (4 beta chains) makes up 4-30% remainder hgb A1/A2 o Smear: M/Hypo anemia with NRBCs  Two or one mutant gene- no real problem

Survival disorders  Intrinsic hemolytic anemia o Hereditary  Hemoglobin defects- SCA, SCT  Membrane defects  Hereditary spherocytosis- deficiency in skeletal membrane proteins o Spectrin, Ankyrin (binding site for spectrin), protein 4.2 (More in Japan), Band 3 (10-20%)

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Spectrin deficiency is most common defect  Reduced cell surface area (spherocytes) Impaired flexibility (decreased survival) Increased membrane permeability to sodium Males and females can both have Laboratory characteristics  Smear- spherocytes  MCHC >36%: only disease where MCHC MIGHT be Slightly elevated Osmotic fragility – red cells suspended in hypotonic solutions, take-up water, swell, and reach critical volume (bursts)  14 test tubes (diff. Conc. NaCl)  Normal – begin hemolysis at 0.45% and complete at 0.30%  Spherocytes = decrease capacity to expand= hemolyze at higher NaCl conc. o Increase fragility in slightly hypotonic solution o Decreased resistance to lysis

 A= thalassemia, B= normal, C= hereditary spherocytosis EMA (eosin-5-Maaleimide) binding test- alternative test for HS confirmation  Measured via flow cytometry  EMA is fluorescent dye that binds to band 3  HS patient have lower mean fluorescence intensity than normal RBC controls  Results reported in % decrease in MFI o Treatment: (spleen destroys spherocytes and causes anemia)  Splenectomy  Possibly transfusions in severe cases  Hereditary elliptocyotsis- Assembly defect of spectrin o Stress in microcirculation and RBC cannot return to normal shape o Mild anemia in 10% of patients Metabolic defects- Glucose –  6-PD deficiency (hexomonophosphate shunt pathway) o Enzymes responsible for regeneration of NADPH o Prevents oxidation of Hgb (Fe kept in ferrous – 2+ state) o Normal G-6-PD isozyme= B o

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 Variant A= 20% black males (a.a. substitution; no reduced activity) – disease not present  Variant A- = 11% black males (a.a. substitution; reduced activity)- active disease Many drugs associated with this deficiency  Prinaquine – also an anti-malaria drug Three phases of hemolysis  Acute (1-3 days)  Decreasing H &H  Hemoglobinuria  Recovery phase (7-10 days)  Retic count peaks at 8-12%

 Increasing H&H Resistant phase – no anemia  Retics resistant to hemolysis o G6PD dye reduction test (Qualitative)  G6PD + NADP (glucose 6 phosphodehydrongenase) NADPH + g-PG  NADPH + blue dye – NADP + colorless dye (complex)  Colorless dye complex= marron-colored solution o Heinz Bodies- visualized with crystal violet stain (NOT WRIGHT STAIN)  Represent precipitated hgb in RBC membrane  Round or oval  Tend to cling to the cell membrane  Pyruvate kinase deficiency – embden-meyer pathway o Last step malfunctions: makes two pyruvate/ 2 ATP o Reduced ATP production  Reduce flexibility of RBCs and sodium potassium pump issues o Rapport Luebering pathway- prevent anemia  Creates high levels of 2,3 BPG Acquired (membrane defect)  Paroxysmal nocturnal Hgb- RBCs hypersensitive to complement  Acquired hematopoietic stem cell disorder  Deficiency of GPI- anchored proteins on cell surface o Leads to complement mediated intravascular hemolysis 

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Two complement regulatory proteins missing in PNH- use GPI to anchor onto membrane o CD55- decay accelerating factor o CD59- member inhibitor of reactive lysis o Complement inhibitors Decrease in CD55/CD59= complement not cleared from RBC= increased lysis Nocturnal – CO2 retained at night o Slightly lowers pH = activated complement Chronic anemia Intermittent exacerbations of acute hemolysis (not known why) o Possibly: stress, infection, surgery etc. Treatment o Transfusion with anemia Iron if IDA develops Bone marrow curative Soliris- relatively new  Blocks complement system (binds C5 and prevents MAC formation= blocks lysis) Sugar water test- screening test for PNH o Sucrose solution- medium of low ionic strength  Promotes binding of complement/activates complement o Complement- sensitive PNH cells are lysed o Normal red cells are unaffected Confirm with flow cytometry – look for CD55/CD59 o o o

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 Extrinsic hemolytic anemia o Acquired  Warm Autoimmune hemolytic anemia – blood banking  Positive direct Coombs  Antibody reacts best at 37 C  Most common (80%)  IgG  Secondary to disease (systemic lupus erythematosus and chronic lymphocytic anemia- most common leukemia in US)  Smear- polychromatophilia and spherocytes  Treatment: o Removed underlying problem (not likely)

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o Steroids (reduce auto antibody- many side effects) o Splenectomy o Want to avoid transfusion Cold autoimmune hemolytic anemia (cause RBCs to agglutinate)  Positive direct Coombs  Antibody reacts at lower temp. (15% incidence) o IgM autoantibody binds to RBC after exposure to cold (vessels near surface of skin) o Activates complement pathway o o  

When RBCs return to circulation (IgM disassociates but C3b components remain on cell) Hemolysis is extravascular

IgM Idiopathic or secondary o Mycoplasma pneumonia (anti-I) o Infectious mononucleosis (anti-i)

Purple top tube/ CBC analyzer o Increase in MCV: because of agglutinated RBCs o Decrease RBC count/hematocrit  Beckman Coultier- hematocrit calculated o H &H problematic (hct = hgb *3 +/- 3) o Causes elevated MCHC – not possible  Need to keep blood sample warm and process immediately (ideally) o Or rewarm to redisburse IgM Paroxysmal cold hemoglobinuria- most often in children with viral infection  Intravascular hemolysis  Bithermal (biphasic) complement- fixing IgG antibody o Ab coasts RBC at 4 C and complement is fixed o Complement sequence is completed at 37 C and lyses cell  Donath-Land Steiner test Drug induced immune hemolytic anemia- decreases H&H  Quindine (cardiac drug)- binds to IgG o IgG/drug complex binds to RBC 

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o Attracts complement- causes anemia o Intravascular hemolysis Penicillin (IV only) on drug attaches to RBC o IgG to drug that is already attached to RBC o Spleen removes because of foreign stuff on RBC o Extravascular hemolysis7-10 days to develop o Does not happen to everyone Aldamet (Used with pregnant women)- alters rH antigen on cell membrane o Treats high blood pressure o IgG binds to RBC o Autoantibody specific to rh antigens on the RBC surface is induced by the drug  Abs bind to cell surface; drug does not o Lingers for long time- even after stopping medication o Positive DAT

DNA disorders o Megaloblastic anemia  Bone Marrow  DNA synthesis problem (nucleus lags behind the cytoplasm in development)  Enlargement of cells  Shift to left – increase of number of immature cells/ death  Hypercellular- marrow tries to make more due to increase in cell death  Intramedullary cell dead- many cells die in marrow  Blood  Increased MCV (uncommon with anemia)

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Pancytopenia- decrease in all cells Hypersegmented polys- more than normal amount of lobes Howell Jolley bodies B12 deficiency- affects geriatric population greatly o Sources: meat, dairy, eggs o Intrinsic factors- comes to B12 in stomach and transport  IF made by parietal cells of stomach o Lower part of Ileum absorbs B12 o Transcobalamin + B12 in small intestine  Transports in blood stream to liver and hematopoietic cells o Several years of B12 stored in liver o Causes  Detective absorption  Diverticular (bacterial utilization)  Diphyllobothrium lactum (fish tape worm- pretty common)  Defective production of IF (pernicious anemia)  Clinically: sore tongue, GI symptoms, neurological problems o Major neurological: MAD in brain (like Alzheimer’s)  Immune abnormalities  Antiparietal cell antibodies  Anti IF antibodies o Antibody assays for pernicious anemia  IF antibodies (70% of cases)  Enzyme-linked immunoabsorbent assays (ELISA)  Highly specific for PA

o Gastrin – hormone produced in pyloric antrum (opening of stomach)  Released into bloodstream when food enters stomach  Carried to gastric cells in stomach by circulatory system  Triggers gastric acid secretion in parietal cells  Pernicious anemia- body of stomach becomes atrophic  Produce less acid in response to parietal cell death  Increase in gastrin response  Even if Ab test negative if B12 levels decreased and gastrin levels are increased = pernicious anemia o Less than 100 pg/mL of B12 Folic acid deficiencies – nutritional intake o Alcoholism o Malabsorption in small intestine o Folic acid antagonists  Methotrexate – chemotherapeutic drug (leukemia drug)  Also treats Rheumatoid arthritis 

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Lab tests for folic acid deficiency  Decreased serum folic acid (reflection of last several days)  Decreased RBC folate (long term intake)  B12, folate and RBC folate- order all three tests at same time  When macrocytic cells with hyper segmented polys Need to confirm IF antibody- pernicious anemia when B12 levels low Need to do B12, folate/RBC folate when you see hypersegmented segs and macrocytes o

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  Stem cell disorders o Anemia of chronic disorders (inflammation) – second most common anemia  3 factors contributing:  Iron is trapped in reticular endothelial cells  EPO production is low (kidneys) o Can respond to pharmalogical precursor (CFU-E)  RBC production is insufficient to compensate for decreased RBC survival

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Lab results – micro/hypo anemia IDA Anemia of CD ↓ ↓ Serum Iron ↑ ↓ TIBC ↓ ↓ % saturation ↓ ↑ Macrophage iron in Marrow ↓ ↑ Ferritin ↑ Transferrin Receptors Normal  TIBC and transferrin receptors used to differentiate Anemia of renal insufficiency  BUN correlates to the anemia  Decreased production of EPO due to damaged kidneys  Decreased RBC survival due to uremia  Uremic condition can result in burr cells and schistocytes  Uremia affects platelet function  Can lead to GI and gynecological bleeding  Iron and folic acid loss can occur in the dialysis tubing  Can end up with megablastic anemia  Treatment: intravenous or subcutaneous administration of EPO  Very low H&H (decrease in hgb) Aplastic anemia  Pancytopenia- decrease in all cellular elements  Marked hypocellular marrow (different from megablastic anemia)  Incidence/year  2 in 1 million  Occurs at any age; peaks 15-25  Clinical features: anemia, infection, hemorrhage  Etiology  50% idiopathic  33% drug-related (chloramphenicol)- topical AM  4% chemicals (benzene) and toxins  4% viral infections  Pathophysiology- direct damage or immune damage to stem cells  Treatment: bone marrow treatment  HLA typing of sibling for donor (identical twin best)  Minimal transfusions  75% of previously untransfused patients achieve 10 year survival with appropriate stem cell donor Inherited aplastic anemia (fanconi’s anemia)

Congenital abnormalities- short stature, mental retardation, abnormal skin pigmentation, hearing, kidney and eye abnormalities  Stem cell transplantation may be curative  Children Pure red cell aplasia- stop making erythrocytes 

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Acquired  Erythroid precursors in bone marrow reduced  Normocytic anemia  Normal platelet and WBCs  May occur during course of viral infections and various drug therapies Inherited red cell aplasia (diamond blackfan anemia)  Requires lifelong support with transfusions

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Polycythemia – general

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Relative- easiest to deal with Absolute  Primary (no or decrease in EPO)- polycythemia vera Secondary (increase in EPO)  Appropriate increase – altitude, tobacco, abnormal hgb  Inappropriate – renal tumors and extra renal tumors Polycythemia vera bone marrow gets turned on and increases cell production (can be cross classified as WBC issue/leukemia)  Increase in hematocrit and hemoglobin  Clonal disorder of a multipotential hematopoietic cell that results in exaggerated proliferation and accumulation of erythrocytic, granulocytic and megakaryocytic cells  Symptoms:  Average age: 60  Headache, weakness, dizziness, sweating and itching  RBC morphology: normocytic, normochromic  Increased Blood pressure, increase...