Hematology/Oncology Exam

Erythropoietin (EPO) is a hormone that

stimulates RBC production of erythrocytes in the bone marrow. It is produced in the kidneys and some in the liver. It travels through the blood to the bone marrow and stimulates immature cells to transform into mature RBCs

Role of Folate and B12

•Deficiency in vitamin B12 •Elevated MMA •Elevated homocysteine •Folate deficiency •MMA normal •Homocysteine elevated •Folate and B12 - necessary for synthesis of nucleic and amino acids

Platelet Plug Formation (Primary Hemostasis)

-Nerves, smooth muscle cells detect injury -Trigger reflexive contraction of vessel (vascular spasm) which decrease blood flow--> decrease blood loss -Secretion of nitric oxide, prostaglandins stop; secretion of endothelin begins--> further contraction

Sickle Cell Anemia: Pathophysiology

-Point mutation in the beta-globin chain -Valine to Glutamine transformation causes change from HbO2 to deoxyhemoglobin

Alpha Thalassemia: Diagnosis

1. CBC -hypochromic microcytic anemia (decrease MCV - 60-75 more pronounced than Fe deficiency) -normal or increased RBC count -normal or increase serum iron and iron studies -Hgb may be as low as 3-6 -peripheral smear: *target cells*, teardrop cells, basophilic stippling -Heinz bodies in Hgb H disease - insoluble Beta chain tetramers -> inclusions inside the RBCs 2. Hgb electrophoresis: normal hemoglobin ratios in adults -ratios stay the same because all 3 Hgb types contain 2 alpha chains so decreased alpha production affects all 3 proportionally

Iron Deficiency Anemia: Clinical Features

1. Pallor 2. Fatigue, generalized weakness 3. Dyspnea on exertion 4. Orthostatic lightheadedness 5. Hypotension, if acute 6. Tachycardia

G6PD Deficiency

A hereditary condition in which red blood cells break down when the body is exposed to certain drugs.

Where is albumin made?

Albumin is made in the liver Electrolytes help maintain normal Acid base physiology in the blood. Also help regulate osmolarity (overall concentration of blood)

Blood compnents

Blood- composed of specialized cells in plasma Plasma is 92% water, 7% protein and 1% other solutes Specialized cells include RBC (erythrocytes); WBC (leukocytes) and platelets (thrombocytes) Hematocrit is the percentage of RBC in the blood, BY volume

AIHA: Clinical Manifestations/Diagnosis

Clinical: •Anemia •Acrocyanosis •Fatigue •Weakness •Dyspnea •Hemoglobinuria •Raynauds •Hepatosplenomegaly (?)

•Three general categories of hematologic disease processes:

Disease of blood components •RBCs, WBCs, platelets, and coagulation factors •Disease of blood-forming tissues •Bone marrow disease, bone marrow failure •Hematologic diseases secondary to other conditions •Anemia and coagulopathy are manifestations of a disease, not diseases in and of themselves

Normal Peripheral Smear- Wright Stain

Eosin (acidic dye), methylene blue (basic dye) and azures (basic dye) used in combination Commonly used as differentiating stain for blood smears, bone marrow, blood parasites Large purple- leukocyte (lymphocyte) Pale red- erythrocyte Small purple- platelets

Leukocytes have two main categories

Granulocytes and agranulocytes Granulocytes—contain membrane bound cytoplasmic granules which are visible when stained. They are larger than erythrocytes but shorter-lived. They contain lobed nuclei. All are phagocytes to some degree. Three types of granulocytes include neutrophils, basophils and eosinophils Agranulocytes lack visible cytoplasmic granules. They are structurally similar to granulocytes but function differently. They have spherical or kidney shaped nuclei. Two types include monocytes and lymphocytes. Lymphocytes can be broken down further into B cells and T cells.

Sickle Cell Anemia: Clinical Manifestations

Jaundice Anemia Pain Organ damage Infection Related to the proportion of HbS in the circulation

Diagnosis: B12 Deficiency

Measurement of plasma B12 Schilling test

RBC Morphology

Spherocytes- lack distinct pale center Schistocytes- fragmented RBC Sickle cell- sick cell anemia Target cell- seen in sickle cell anemia

In the bone marrow there are proerythroblasts (immature RBCs).

The kidneys produce a constant level of EPO which gets released into the blood and makes its way into the bone marrow. It binds to the EPO receptors on the immature RBCs. This causes them to mature into erythrocytes. This process is constant.

If there is decreased delivery of oxygen to the tissues, the kidneys will EPO also prevents

ramp up production of EPO to increase mature RBC which help deliver the oxygen. immature RBC from killing themselves via apoptosis. Without EPO, developing RBCs die via apoptosis

•GP1B surface proteins on platelets bind to

Von Willebrand factor

iron deficiency anemia

anemia resulting when there is not enough iron to build hemoglobin for red blood cells

Lead poisoning Clinical Manifestations

anorexia, irritability, insomnia NEURO - developmental delays, hearing loss, acute encephalopathy

Hemostasis: body prevents

blood loss

Decreased delivery of oxygen to the tissues can be due to

either decreased blood flow or decreased oxygen content in the blood. For decreased blood flow, increasing the number of RBCs will not be effective. If there is decreased oxygen content, increasing the number of RBCs will be effective. The kidneys can distinguish between the two scenarios above.

•Damage to endothelial cells •Damaged cells release Von Willebrand factor (binds to collagen)

exposes collagen

•Splenomegaly or previous splenectomy may be due to

hematologic disease process

•Platelet changes shape (forms arms to grab other platelets), releases more von Willebrand factor, serotonin, calcium, ADP, thromboxane A2 (positive feedback loop)—limited to •ADP, thromboxane A2 results in GPIIB/IIIA expression

injury site

For decreased blood flow, the kidneys are not as well perfused. This leads to

less fluid being filtered in the glomeruli which means less solutes need reabsorbed and saved from being urinated out by the tubular cells (requires energy from oxygen)- so there is less demand for oxygen. Even though oxygen supply is down, because the oxygen demand is down the cells will still have enough oxygen. There will not be production of EPO.

For decreased oxygen content, there is less oxygen supply but adequate blood flow. More fluids are getting filtered, and more solutes are filtered which need reabsorbed. Tubular cells need increased energy which requires oxygen. This means there is a high demand for oxygen but lack of supply. EPO will be stimulated. All cells in kidneys can produce EPO. For patients with chronic kidney disease, they have

less kidney mass which means they produce less EPO. This will cause anemia.

•GPIIB/IIIA binds to fibrinogen, links platelets-->

platelet plug

Serotonin-attracts more -- Calcium- secondary hemostasis

platelets

Extrinsic- activated by Intrinsic-

tissue factor and found outside the blood factors required for activation are found in the blood Both are activated independentlyà activation of factor X then coagulation cascade (common pathway) Intrinsic pathway is activated by collagen and activated platelets Subendothelial collagen is exposed due to trauma

Decreased hematocrit= Increased hematocrit=

too few erythrocytes can be caused by dehydration. When there is less liquid in blood, the percentage of erythrocytes are higher.

Hemoglobin: Structure

•2 α chains, 2 β chains •Each chain binds a heme group •Each iron atom can bind one O2 molecule •One Hb molecule can transport 4 O2 molecules

Granulocytes- Eosinophils

•2-4% of WBC •Bilobed nucleus •Cytoplasmic granules stain reddish with acid dyes. Granules are packed with digestive enzymes but LACK enzymes that digest bacteria •Concentrated in loose connective tissue in respiratory and intestinal tract •Defend against parasitic worms by releasing digestive enzymes- coat surface of parasitesà death •Complex role in diseases such as asthma and allergies •

Normocytic Anemias: Common Causes

•Anemia of chronic disease •G6PD deficiency •Sickle cell disease •Hereditary spherocytosis •Autoimmune hemolytic anemia •Paroxysmal nocturnal hemoglobinuria • Most Result in hemolytic anemia

G6PD Deficiency: Clinical Manifestations/Diagnosis

•Asymptomatic until episodes of oxidative stress •Episodic hemolytic anemia: •Common symptoms of anemia (fatigue, pallor, etc) •Splenic RBC sequestration -> Hemolytic crisis •Back/abdominal pain, jaundice, splenomegaly, acute renal failure in neonates in severe cases, neonatal hyperbilirubinemia •Diagnosis: •Peripheral smear: •Normocytic, normochromic hemolytic anemia •Schistocytes (bite cells) •Heinz bodies (denatured hemoglobin) •Labs: •Reticulocytosis, increased indirect bili, decreased haptoglobin, increased RDW •G6PD fluorescent spot test (screen)- measures the generation of NADPH from NADP+; the test is positive if the blood spot fails to show fluorescence under ultraviolet light •If screening test +, G6PD activity is measured

Beta Thalassemia Diagnosis: Hgb Electrophoresis

•Beta thalassemia trait •Increase in Hgb A2 - decreased beta chains -> alpha chains couple with delta chains •Beta thalassemia major •Little to no normal adult Hgb (Hgb A) •Alpha chains couple with gamma chains -> increase in Hgb F

Blood Physical Characteristics and Volume

•Blood is slightly alkaline: pH 7.35-7.45 •Temperature is slightly higher than body temp (100.4 F) •Accounts for about 8% of body weight •Healthy adult males- average volume 5-6 L •Health adult females- average volume 4-5 L

Blood Transfusions

•Blood transfusion: person receives blood/elements of blood (usually through intravenous infusion) •Homologous transfusion: anonymous donor •Autologous transfusion: self-donor (planned surgery) •Blood is mixed with sodium citrate to prevent coagulation, refrigerated/frozen for storage

Beta Thalassemia Diagnosis: X-rays

•Bossing of the skull with "hair on end" appearance •Result of extramedullary hematopoiesis that results in new bone formation in the skull producing perpendicular radiations

Sickle Cell Disease: Diagnosis

•CBC with peripheral smear: •Hb LOW, Hct LOW, increased reticulocytes, target cells, sickled RBC's, Howell-Jolly bodies - nuclear remnants (functional asplenia) Sickle Cell Disease: Hgb Electrophoresis

Beta Thalassemia: Diagnosis

•CBC: •MCV low •RBC count may be increased •Serum iron may be increased •Peripheral smear: •Target cells •Teardrop cells •Basophilic stippling •Nucleated RBC's

Alpha Thalassemia: Management

•Carrier - none •Mild disease (trait) - none •Moderate disease (⍺-Thal. Minor) - folate, avoid oxidative stress (sulfa drugs), avoid supplemental iron •Severe disease (Hb H): •Blood transfusions weekly •Iron chelation therapy •Splenectomy (stops RBC destruction) •Bone marrow transplant (Hgb H) •Hb Bart's - incompatible with life

Lead Poisoning

•Cause of 540,000 deaths in 2016 •More common in developing countries •Exposure: •Contaminated air, water, dust, food, or consumer products •Children - everything goes in the mouth, including objects that contain lead paint -> greater risk •Preventable!!!

Anemia of Chronic Disease

•Caused by conditions resulting in chronic inflammation: •Infection •Autoimmune disorders •Malignancy •DM •Pathophysiology: •Acute phase reactants interfere with normal hemoglobin production → sequestering iron •Diagnosis: •Normochromic, normocytic anemia •Normal or increased ferritin, decreased TIBC, Decreased serum Fe •Treatment: •Treat underlying disease

Intrinsic Pathway

•Circulating factor XII contacts negatively charged phosphates on platelets/subendothelial collagenà factor XIIa •Factor XIIa cleaves factor XIà factor XIa •Factor XIa + calcium cleaves factor IXà Factor IXa •Factor IXa + factor VIIIa (binds to Von Willebrand factor) + calciumà enter the common pathway

Plummer-Vinson Syndrome

•Classic triad of: •Iron deficiency anemia •Esophageal web •Atrophic glossitis •Presents with: •Anemia •Dysphagia •Beefy-red tongue

Paroxysmal Nocturnal Hemoglobinuria (PND) Symptoms

•Clinical manifestations: •Anemia with dark "tea" colored urine at night and early morning •Increased risk for thrombosis - Hgb binds with nitric oxide. ↓ NO -> hypercoagulable state •Pancytopenia - GPI derived from STEM cells, all cell lines can be affected •Main cause of death: thrombosis of the hepatic, portal or cerebral veins •Destroyed platelets release cytoplasmic contents into the circulation inducing thrombosis

Hematologic History

•Common Symptoms by System •General: fatigue, weakness, fever, malaise •HEENT: headache, pallor, epistaxis, mouth ulcers, icterus, loss of taste, bleeding from gums •Respiratory: SOB •Cardiovascular: palpitations, tachycardia •Gastrointestinal: nausea, vomiting, abdominal distension, dyspepsia, diarrhea, rectal bleeding •Genitourinary: hematuria •OB/GYN: menorrhagia •Dermatologic: easy bruising, rashes, ecchymosis, petechiae •Psychiatric: depression, insomnia, mania, restlessness, mood changes

Sickle Cell Anemia

•Common in African American, Mediterannian, Carribean, Middle Eastern, and Central American populations •Autosomal recessive intracorpuscular defect •Valine is substituted for glutamic acid during formation of each beta chain •Caused by the abnormal formation of Hb beta chains: •Normal: Hb A = 2 alpha, 2 beta •Sickle cell disease: Hb SS = 2 alpha, 2 S •Sickle cell trait: Hb AS = 2 alpha, 1 normal beta, 1 S beta •Chronic anemia -> pain, disability, risk of infection, early death

Folate Deficiency

•Common in alcoholics, malnourished, non-veggie eaters •Primary source of folate - fresh veggies, cereals, grains •Other etiologies: •Pregnancy, medications - Bactrim (sulfa drugs), phenytoin, methotrexate •Folate deficiency more common than B12 -> healthy person only stores about 3 month supply •Absorbed in jejunum •Also necessary for DNA synthesis/RBC maturation

Clinical Manifestations: B12 and Folate Deficiency

•Common to both: •Pallor •Fatigue •Glossitis •Macrocytic anemia •B12 only: •Neurological manifestations •Paresthesias, gait abnormalities, memory loss, dementia •Folate deficiency NOT ASSOCIATED WITH NEUROLOGICAL SYMPTOMS

•Erythrocytes

•Comprise 45% (hematocrit) of total blood volume •Carry O2 to tissues; bring CO2 to lungs •Biconcave discs (depressed center) •Fit through vessels •Increase surface area for gas exchange •No organelles •Increase space for hemoglobin •Life span of mature RBC's- 100-120 days •Engulfed and destroyed by macrophages •Regenerated in bone marrow

•Plasma

•Comprises 55% of total blood volume •No cells: 90% water + proteins, electrolytes, gases •Albumin: maintains oncotic pressure (keeps water in bloodstream), acts as transport protein (shuttles fatty acids, calcium, lipid soluble hormones, and even some meds around the body) •Globulins: antibodies (stick to pathogens and label them for destruction), transport proteins (fats, metal ions, and fat-soluble vitamins) •Fibrinogen: involved in clot formation (helps platelets attach to form initial plug) •Electrolytes: include sodium, potassium, calcium, chloride, carbonate

•Buffy Coat

•Comprises <1% total blood volume •Contains platelets, leukocytes (WBC) •Platelets clump togetherà seal damaged blood vessels •Leukocytes ward off pathogens, destroy cancer cells, neutralize toxins

Alpha Thalassemia

•Decreased production of alpha globin chains due to one or more missing alleles -> excess unstable beta chains are produced -> ↑ RBC destruction •Usually due to gene deletion •Most common in Southeast Asian population (68%), Africans (30%), Mediterranean (5-10%) •Four alleles (genes) encode alpha globin chains. More affected alleles = more severee •Autosomal recessive

Platelets

•Develop from common stem cells in bone marrow •Not true cells- cytoplasmic fragments (small pieces that split off larger cells called megakaryocytes in the bone marrow) •Cytoplasmic granules contain factors that aid in clotting process •Main role- clump together and form a plug that helps seal off a damaged blood vessel and prevent blood loss

History: Disorder of Coagulation Factors

•Disorders of coagulation factors can result in hypercoagulability and hypocoagulability •Do you have or have you ever had •Bleeding disorder •Clotting disorder •Think about questions pertaining to the symptoms of •Joint disease •Ecchymosis •Easy bruising •Vision loss •Anemia •Neurologic or psychiatric problems •hematuria

History: Disorder of Platelets

•Disorders of platelets can result in hypercoagulability and hypocoagulability •Do you have or have you ever had •Bleeding disorder •Clotting disorder •Think about questions pertaining to the symptoms of •Blood clots •Limb pain or swelling •Shortness of breath •Easy bruising •Bleeding problems

Blood Functions

•Distribution •Transport O2 and CO2 •Transport metabolic waste products •Transport of nutrients from digestive tract •Transport of hormones •Regulation •Maintains body temperature •Maintain normal pH •Maintains adequate circulating volume •Protection •Prevention of blood loss-- clot formation •Prevention of infection- WBC's, antibodies, complement, etc.

History: Disorder of blood-forming tissue

•Do you have or have you ever had •Bone marrow disease •Bone marrow failure •Think about questions pertaining to the symptoms of •Fever •Cachexia •Malaise •Weakness

History: Disorder of RBCs

•Do you have or have you ever had anemia? •Think about questions pertaining to the symptoms of •Weakness •Fatigue •Malaise •Decreased energy level •Pale skin •Numbness/coldness in hands or feet

Bleeding History Questions

•Duration of bleeding? •Where and type? •Mucous membranes •Skin •Joint •GI •GU •How long? •Acute or lifelong •Appearance of petechiae on body, ecchymosis, new limb swelling?

Why is EPO important?

•Every cell in the body uses oxygen for cellular respiration •As we breathe, oxygen diffuses into the blood stream where it binds to hemoglobin within the RBCs and gets carried off to various parts of the body •RBCs only live 120 days, so there is a constant need to produce new cells

Autoimmune Hemolytic Anemia (AIHA)

•Extracorpuscular hemolytic anemia •Not very common: 1-3 cases/100,000 people per year •Primarily in adults but can be seen in kids with primary immunodeficiency •Most common cause - idiopathic •Other causes - malignancy, drugs (PCN, methyldopa), infection •Two forms: •Warm agglutinin •Cold agglutinin

Common Pathway

•Factor X is cleaved- factor Xa •Factor Xa cleaves factor V- factor Va •Factor Xa + factor Va + Calcium--> prothrombinase complex •Prothrombin (factor II)à thrombin (factor IIa) •Thrombin activates platelets, cofactors (V, VIII, IX); cleaves fibrinogen, stabilizing factor (--> factor XIIIa + calcium--> cross-links in mesh)

HS: Management

•Folic acid helps maintain new RBC production •Splenectomy in severe disease •Stops RBC destruction in spleen •Transfusions •EPO

Blood Products

•Fresh whole blood •RBC, plasma, fresh platelets •All these elements are available in other products •Usually only used with massive blood loss (trauma) •Packed Red Blood Cells •Most commonly used to raise hemoglobin (anemia) •One unit raises Hgb approximately 1 g/dL •Leukocyte-poor blood •Most blood products are leukoreduced •Reduces certain complications •FFP •Contains all coagulation factors (Clotting factor deficiency) •Used to correct deficiencies or prevent coagulopathy in trauma patients receiving massive transfusions of PRBC •Cryoprecipitate •Made from fresh plasma by cooling it and collecting the precipitate •Contains fibrinogen, factor VIII, and von Willebrand factor

Hematologic History- •Characterizing Symptoms

•How long have you had this symptom? •Symptom that has been present for many years is more likely to be benign or congenital •What is your race/ethnicity? •Some hemoglobinopathies (ex: G6PD deficiency) are more common in certain ethnic groups, and some disease process (ex: sickle cell anemia) are related to race •Have you received treatment for hematologic disease? •Some treatments are very common (iron supplementation) •What work-ups, if any, have already been done?

Cold Agglutinin AIHA

•IgM binds to RBC surface proteins •Activates complement cascade •Intravascular complement-mediated RBC lysis at temperatures well below normal body temp (< 37) •Complement proteins accumulate on RBC surface (opsonisation) •Opsonization leads to phagocytosis in liver, spleen -> extravascular hemolysis •Primary or secondary causes •Primary - idiopathic •Secondary - infections (Mycoplasma, EBV), malignancy

Hemolytic Anemia: Classifications

•Intracorpuscular hemolysis (defects in RBC) •Membrane/cytoskeletal defects •Hemoglobin defects •Enzyme defects •Extracorpuscular hemolysis (defects outside RBC) •Nonimmune •Immune

Paroxysmal Nocturnal Hemoglobinuria (PND) TX

•Iron and folate •Steroids help reduce hemolysis •Eculizumab (anti-complement C5 Ab)

Agranulocytes- Monocytes

•Largest of the leukocytes and account for 5% of WBCs •Nucleus is U or kidney shaped when stained •Crucial in defense against viruses, certain intracellular bacterial parasites, chronic infections (TB) •Leave the bloodstream in response to chemotactic factors, differentiate into highly mobile macrophages—phagocytize (gobble up bacteria or other pathogens) •Act as antigen presenting cells: activate lymphocytesà mount bigger immune response

Coagulation (Secondary Hemostasis)

•Last two hemostasis steps: clotting factors activate fibrin, build fibrin mesh around platelet plug •Begins with either extrinsic/intrinsic pathway; factor x activation--> coagulation cascade (common pathway)

Warm and Cold AIHA: Diagnosis

•Warm: •Direct Coombs + •Polychromatophilic red cells (A) •Spherocytes (B) •Schistocytes (C) •Nucleated red blood cells (D) •Cold: •Direct Coombs + •Microspherocytosis (A) •Nucleated RBC's (B) •RBC clumps (C)

Hereditary Spherocytosis

•MC hemolytic anemia due to RBC membrane defect •Autosomal dominant; common in Northern Europeans •Intracorpuscular defect/deficiency in cell membrane protein(s) •Ankyrin MC affected loci •Spectrin •Protein 3 •Pathophysiology: Deficiency/defect interferes with normal RBC flexibility •Results in abnormal sphere-shaped RBC's that are prone to rupture •Leads to early hemolysis and destruction in spleen

Iron Deficiency: Diagnosis

•MCV and MCH - microcytic, hypochromic •Serum ferritin, serum iron - low •TIBC - elevated (transferrin saturation with Fe low) •RBC count, Hgb, Hct, MCV all low •RDW - increased

Macrocytic anemias: Common Causes

•Megaloblastic (hypersegmented neutrophils) •B12 Deficiency •Folate Deficiency • •Non-megaloblastic •Liver disease

Beta Thalassemia: Clinical Manifestations

•Minor - asymptomatic. May have mild anemia •Intermedia - Anemia, hepatosplenomegaly, bony disease •Major (Cooley's Anemia): •Asymptomatic at birth (due to fetal Hgb) •Symptomatic at 6 months (fetal Hgb declines) •Frontal bossing and maxillary hyperplasia due to extramedullary hematopoiesis •Hepatosplenomegaly •Severe anemia with jaundice, dyspnea, and pallor •Osteopenia (pathologic fractures) •Iron overload •Pigmented gallstones

Granulocytes- Neutrophils

•Most common (60% of leukocytes) •First to respond to an infection •Chemically attracted to sites of inflammation •Nuclei consist of 3-6 lobes (polymorphonuclear)- number increases as they age •Cytoplasmic granules stain with both basic (blue) and acidic (red) dyes: contain hydrolytic enzymes and antimicrobial proteins (defensins) •Responsible for bacterial killing via respiratory burst: •Oxygen metabolites plus defensin proteinsà cell lysis

Warm agglutinin AIHA

•Most common form of AIHA •IgG binds to RBC surface antigens •Antibodies are activated at body temp •RBC's are phagocytized and destroyed in spleen - extravascular hemolysis •Underlying causative disorders (other than idiopathic) •SLE - most common secondary cause •Malignancy (CLL) •DRUGS: penicillin, methyl-dopa

Vitamin B12 Deficiency

•Most common in alcoholics, malnourished, vegans •Primary source of B12 is animal products (meats, eggs, milk) •Deficiency is rare in healthy individuals - B12 stored in liver (2-3 yrs) •B12 also necessary for myelination - deficiency can cause paresthesias, gait abnormalities, memory loss, dementia •Other risk factors: •Bariatric surgery •Crohn's disease if ileum involved •Pernicious anemia - autoimmune destruction of gastric parietal cells -> lack of intrinsic factor -> needed for B12 absorption in ileum

Anticoagulation

•Occurs during primary, secondary hemostasis; regulates clot formation •Prevents clots from growing too largeà block blood flow, form emboli •Regulation starts with thrombin (factor II) •Multiple pro-coagulative functions •Protein C, S bind thrombomodulin-thrombinà cleaves, inactivates factors V, VIII •Antithrombin III binds thrombin/factor X --> inactivates both (plus factors VII, IX, XI, XII with lower affinity) •Other factors prevent platelets adhering during primary hemostasis •Nitric oxide, prostacyclinà decrease thromboxane A2

Leukocytes

•Only formed element with nuclei and organelles (complete cells) •Far less numerous than RBC's (<1% of total blood volume) •Capable of leaving the bloodstream (diapedesis) and entering body tissues to defend against disease (bacteria, viruses, toxins, tumor cells, etc.) •Detect chemical compounds released by damaged cells or other leukocytes and gather in large numbers (positive chemotaxis) •Mount an inflammatory response to control tissue damage, infection, etc. •Result is increased WBC count (leukocytosis) in the blood •Life cycle varies according to particular leukocyte

Sideroblastic Anemia

•Overview •Sideroblastic anemias are a group of inherited and acquired anemias in which iron accumulates in the mitochondria of erythrocyte precursors •Ringed sideroblasts (iron-laden erythrocytes with Prussian-blue stained mitochondria) seen on bone marrow aspirate •Epidemiology: •Incidence - rare •Demographics •More common in males •Median age of occurence - 74 years •Risk factors: •Alcoholism •Vitamin B6 deficiency •Lead poisoning •Copper deficiency

Sickle Cell Anemia: Management

•Pain control •IV hydration & O2 - first step •Narcotics - morphine, dilaudid •Hydroxyurea - reduces frequency of pain crises •Folic acid - stimulates production of new RBC's, DNA synthesis •Immunizations - S. pneumo, H. flu, Meningococcal •Prophylactic penicillin - 4 months through 6 years of age •RBC transfusions for severe sickle cell crises •Curative - stem cell transplant. Significant side effects •Sickle cell trait •Heterozygous Hgb A/S; usually asymptomatic •May have episodes of hematuria/inability to concentrate urine but usually asymptomatic •Some resistance to malaria

Lead Poisoning: Pathophysiology

•Pathophysiology •Lead inhibits key enzymes in heme synthesis pathway •Leads to ↓ heme synthesis •Results in ↑ RBC protoporhyrin •Lead inhibits rRNA degradation -> causes rRNA to aggregate in RBCs -> visualized as basophilic stippling of RBCs on peripheral smear •Lead causes toxicity through the generation of reactive oxygen species

SA: Pathophysiology

•Pathophysiology: •Mitochondrial pathways in erythrocyte precursors are disrupted, leading to accumulation of iron in the mitochondria •Excessive iron deposits in erythroblasts form a ring around the nucleus •Ringed sideroblasts (iron-laden erythrocytes with Prussian-blue stained mitochondria) seen on bone marrow aspirates and peripheral smears •Heme synthesis is impaired leading to ↓ heme production and abnormal RBCs

HS: Diagnosis

•Peripheral smear •Hyperchromic ROUND RBC's (spherocytes) lacking central pallor •RBC fragments (schistocytes) •Increased RDW and MCHC •+ osmotic fragility test •RBC's easily rupture in hypotonic solutions •Increased permeability to salt and water -> rupture •Flow cytometry

Diagnosis: Folate Deficiency

•Peripheral smear: •Large RBC's •Hypochromic •Hypersegmented neutrophils, macroovalocytes •↓ folate, normal B12, ↑ homocysteine •PO folic acid •Will not help neurologic symptoms if B12 deficient

Hemolytic Anemia

•Premature destruction of RBC's •Hemoglobin breakdown products retained in blood •Increased circulating reticulocytes due to increase in erythropoiesis •Increase in serum LDH (abundant in RBC's) •Increase in indirect bilirubin -> Jaundice; Direct bilirubin may also begin to accumulate -> dark urine •Decrease in haptoglobin -> bound by free Hb and depleted •Most are: •Normocytic •Normochromic

Paroxysmal Nocturnal Hemoglobinuria (PND)

•Rare, idiopathic mutation in GPI protein on surface of RBC membrane •GPI: Anchors DAF (decay accelerating factor) & MIRL (membrane inhibitor of reactive lysis) •GPI protein normally protects RBC's from complement •When mutated, complement mediated hemolysis ↑ leading to intravascular RBC destruction •Occurs at night - slightly more acidotic state -> complement more active •Complications of PND •Iron deficiency anemia •AML

Granulocytes- Basophils

•Rarest WBC- 0.5-1% of leukocyte population •U or S shaped nucleus •Cytoplasmic granules contain histamine (stains purplish-black) •Binds IgE- causes release of histamine •Histamine acts as a vasodilator and attracts other WBC's to sites of inflammation •Important component of allergic responses

Lead: Management

•Remove source of lead •Chelation therapy if severe (Succimer, penicillamine, Dimercaprol) •Screening - especially in children

AgranulocyAgranulocytes- Lymphocyte

•Second most common type of WBC: >25% of WBC population •Large purple nucleus when stained, occupies majority of the cell •Usually slightly larger than RBC •Small proportion found in bloodstream, but most are associated with lymphoid tissues (lymph nodes, spleen, etc.). •Responsible for adaptive immune response- antibody production and allows our immune system to have "memory" •Crucial role in immunity and classified accordingly: •T lymphocytes: act directly against virus-infected cells and tumor cells •B lymphocytes: precursors to plasma cells which produce antibodies •Natural killer cells

SA: Diagnosis & Treatment

•Serum labs •↑ serum iron and ferritin •↓ TIBC •↓ or normal MCV •Peripheral blood smear •Hypochromic RBCs •Pappenheimer bodies in RBCs •Abnormal basophilic granules of iron •Low reticulocyte count •Bone marrow stained with Prussian blue •Ringed sideroblasts •Diagnostic hallmark of all sideroblastic anemias •Treatment: •Pyridoxine (vitamin B6)

Lead: Diagnosis

•Serum lead levels - greater than 10 µg/dL is cause for concern •Serum iron and ferritin increased •TIBC decreased •Peripheral smear: •Hypochromic/microcytic RBC's •Basophilic stippling on peripheral smear •Ringed sideroblasts in bone marrow •Lead lines in gums and bones

Paroxysmal Nocturnal Hemoglobinuria (PND) DX

•Sucrose test: used to screen •Flow cytometry best screening test •Can detect the lack of CD55 (DAF)

SA: Signs/Sxs

•Symptoms •General symptoms of anemia •Fatigue •Weakness •Dyspnea on exertion •Lack of coordination (cerebellar symptoms) •Diarrhea •Physical exam •Growth delay in children •Ataxia •↓ deep-tendon reflexes •Incoordination •Dyspnea •Muscular weakness

Cross Matching

•Test to confirm donors blood is safe for recipient •Recipient serum is mixed with donor blood •Agglutination reaction: cannot receive

Beta Thalassemia: Management

•Trait - No care necessary. Genetic counseling may benefit •Major/severe anemia: •Periodic blood transfusions •Vitamin C and folate supplementation •Avoid excess iron •May require iron chelation (Deferoxamine) •Splenectomy if refractory •Bone marrow transplant

Blood Typing

•Transfusion blood types not compatibleà autoimmune reaction (hemolytic transfusion reaction) •Two classification systems (based on presence/absence of proteins) •ABO system; Rh system •ABO system •Determined by type of glycoproteins found on RBCs •Type A; Type B; Type A&B; Type O (neither) •Immune system produces antibodies against absent glycoproteins •Type AB: no antibodiesà universal recipients •Type O: no antigensà universal donors •Rh system •Determined by presence of Rh protein (positive or negative) •Rh+ can receive blood from either group •Rh- can only receive Rh- blood

Extrinsic Pathway

•Trauma damages blood vessel, exposes cells under endothelial layer •Tissue factor (factor III) embedded in membrane •Factor VII in blood binds to tissue factor, calciumà VIIa-TF complex Tissue factor and calcium are considered cofactors. They MUST bind to enzyme VIIa-TF complex cleaves factor X which makes it into active form (Xa) 2 blood tests to test coagulationà 1.Prothrombin time (PT)- tests extrinsic pathway 2.Activated partial thromboplastin time (PTT)- tests intrinsic pathway

Beta Thalassemia

•Two alleles encode beta chains •Reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from clinically asymptomatic individuals to severe anemia •Leads to the underproduction of HbA. Reductions in HbA available overall to fill the red blood cells in turn leads to microcytic anemia •Common in mediterranian, African, Indian, and Asian populations •Due to gene mutation •Autosomal recessive

Iron Deficiency: Treatment

•Usually managed with PO ferrous sulfate - 375 mg BID-TID •Lower doses may be used if significant GI side effects •Nausea •Vomiting •Constipation •Cramping •Vitamin C helps increase absorption of Fe

G6PD Deficiency Treatment

•Usually self-limited •Avoid offending foods, medications •Severe cases: •Folic acid and iron •Blood transfusion if necessary

Role of Vitamin K in Coagulation

•Vitamin K regulates blood coagulation •Converts coagulation factors into mature forms •12 coagulation factors (I-XIII, no factor VI); factors II, VII, IX, X require vitamin K •Quinone reductase reduces vitamin K quinone (dietary form) into vitamin K hydroquinone •Vitamin K hydroquinone donates electrons to y-glutamyl carboxylase, converting non-functional forms of II, VII, IX, X into functional forms •Adds chemical group made of one carbon, two hydrogens, one oxygen to glutamic acid residues on proteins •After carboxylation step, vitamin K (as vitamin K epoxide) is converted back into vitamin K quinone via epoxide reductase •Coagulation factors appear in all coagulation pathways

AIHA: Treatment

•Warm •Corticosteroids •IVIg •Treat underlying disease •Splenectomy or Rituximab •Cold •Avoid cold exposure •Treat underlying disease •Rituximab •Plasmapheresis