Hematology

What are the 3 stages of iron deficiency?

1) Depletion of iron stores (decreased serum ferritin, decreased iron in BM). 2) Decrease transport iron (decreased TIBC, decreased serum iron) 3) Anemia (decreased MCV, decrease Hb level, reduced Reticulocyte count, high RDW or variation in RBC size, peripheral smear with hypochromia, microcytosis, aniso, and poikilocytosis).

How much iron is removed from the body per day and how?

1-2 mg of iron by desquamation of epithelial cells of the GI tract and menstruation

What does hemoglobin consist of?

4 globin chains, 4 heme groups

4. A 68 year old woman with rheumatoid arthritis has blood test as recorded below. Her joint symptoms have been unchanged for the last 3 months. Hematocrit 29 % Reticulocyte count 1.0 % Serum iron 35 ugm/dL Serum ferritin 350 ng/L. It would be appropriate to do which one of the following at this time ? A. No further laboratory evaluation. B. Colonoscopy. C. Bone marrow aspiration with stain for iron stores. D. Prescribe recombinant erythropoietin. E. Prescribe oral iron supplements.

A

6. Which one of the following is observed first in a patient who is becoming iron deficient? A. Decreased stainable iron in bone marrow. B. Decreased serum iron. C. Desaturation of serum transferrin. D. Decreased serum transferrin. E. Microcytosis on peripheral blood smear.

A

Describe anemia of chronic disease.

ACD is the most common cause of anemia for hospital inpatients and is asscoated with inflammatory conditions like rheumatology, infectious, and malignant. Hepcidin synthesis increases in inflammatory states via IL-6 which decreases the amount of iron in the blood via Ferroportin degradation. Usually normocytic although may be microcytic. It may require parenteral iron to bypass decreased iron absorption.

What are some examples of genetic hemochromatosis?

AR mutations: HFE (most common), TFR, HJV, Hepcidin AD muations: Ferroportin with Hepcidin resistance

What are some causes of neutrophilia (in order of most common)?

Acute infection, corticosteroids, autoimmune disease, leukemoid reaction, blood cancers.

What are 3 components of plasma?

Albumin, immunoglobulins (antibodies), and other proteins.

How are erythrocytes destroyed in extravascular hemolysis?

Antibodies to RBC attach to the RBC and then to a splenic macrophage via the FcyR that starts to destroy it.

5. A 59 year old man comes to his physician because of fatigue which has been increasing in severity over the last three weeks. He has no other symptoms. His physical examination is unremarkable except for pallor. Laboratory studies: Hematocrit 24 % MCV 68 fl Reticulocyte count 1.1% Serum ferritin 8 ng/ml. He is most likely to have a malignancy arising in which one of the following sites? A. Antrum of the stomach B. Cecum C. Tail of the pancreas D. Sigmoid E. Fundus of the stomach

B

Describe bands.

Bands are immature neutrophils. "Bandemia" is present in serious infections. They have a U shaped nucleus.

SUMMARY: HEMATOPOIESIS

Basic knowledge of blood cell function and morphology is essential for physicians. Blood cell production is regulated through negative feedback mechanisms. Blood diseases arise from abnormal cell quantity or function.

Describe basophils.

Basophils are the rarest leukocyte. Their granules contain histamine and heparin. They function is unknown (not required for life) but they are elevated in hematologic neoplasia (i.e. CML). They have purple granules, include over the nucleus, and a bilobed nucleus.

Why is iron normally present complexed with proteins?

Because it is highly reactive

What does a peripheral blood smear from a patient with G6PD deficiency look like?

Bit cells and blister cells. May also have Heinz bodies (clumps of hemoglobin).

Where is available iron generated?

By macrophages that recycle RBC iron.

7. A 24 year old man comes to his physician for advice after learning that his father was diagnosed with hemochromatosis at age 50. Which one of the following statements is most likely to be correct? A. The inheritance is sex-linked recessive so he has no risk of the illness. B. If he has the illness, he will be advised to initiate therapy with an iron chelating (binding) medication. C. If his sister has inherited the causative gene, she would likely develop the disease at an older age than her father. D. The underlying defect is impaired iron excretion from the body. E. Most mutations associated with hemochromatosis result in increased production of hepcidin.

C

1. A band is seen on a perpherial blood smear stained with Geimsa. The patient most likely had which one of the following? A. Coxsackie viral infection. B. Acute granulocytic leukemia. C. Septicemia with E. coli. D. Vitamin B12 (cobalamin) deficiency. E. Infestation with Ascaris lumbricoides. F. Acute myocardial infarction.

C.

Describe iron deficiency in children.

Children need more iron than adults especially during periods of rapid growth (i.e. 1st, adolescence). Iron deficiency in children is associated with impaired growth and cognitive development which can be irreversible. They do not perform or learn well.

What are some clinical manifestations of iron deficiency?

Chlorosis, decreased aerobic energy (.e. Latex study and hookworm), pica and geophagia or pagophagia, spoon nails, blue sclera.

What is the second step to figuring out the type of hemolysis?

Coombs positive: Is it warm or cold antibody Coombs negative: Is it inherited or acquired

2. A 39 year old man presents to the Emergency Room after vomiting blood thirty minutes ago. For the last two weeks he has been having upper abdominal pain which has been relieved by antacids and over the counter H2 blockers. In the Emergency Room he vomits 500 ml of bright red blood. He has had no other major medical problems and was taking no medications until the present illness. His blood pressure is 110/80 mmHg with a heart rate of 95 beats/minute lying down and going to 90/60 mmHg and 120 beats/minute sitting up. His physical examination is otherwise unremarkable. He is most likely to have which set of laboratory findings at this time? Hct (%) MCV (fl) Reticulocyte count (%) A. 24 92 1.4 B. 24 70 5.0 C. 48 70 5.0 D. 48 92 1.4 E. 48 70 1.4

D

8. Which one of the following statements about hemochromatosis is most likely to be correct? A. Cardiac abnormalities are reversed by appropriate therapy. B. A diet with reduced iron content is the best therapy. C. A single "founder" genetic abnormality accounts for all cases. D. The inheritance pattern is most commonly autosomal recessive. E. Increased skin pigmentation is due to iron deposition in the adrenal glands.

D

What is 2 signs of hemochromatosis?

Dark red or brown liver, iron accumulation in BM

What do microspherocytes look like on peripheral blood smear? What do they show?

Darker color, no light in the middle. IgG mediated or warm hemolysis.

How is iron transported?

Di-Ferric Transferrin carries iron to the hepatocyte, macrophage, or erthropoeitic cell where it binds to a transferrin receptor (TFR1 or TFR2), where it is internalized for intracellular usage or stored as ferritin.

What is the diagnosis and treatment of G6PD deficiency?

Diagnosis: Testing, NEVER test during an acute hemolytic episode (may be false negative because of young surviving cells with most G6PD), wait a month Treatment: Avoid triggers, transfusion

How is iron deficiency anemia diagnosed?

Dietary and GI history, history of blood loss, occult blood in stool, physical exam, lab tests.

How is iron deficiency anemia treated?

Dietary counseling, treat source of blood loss, iron supplementation (increasing time between administrations).

What are 4 types of mechanical destruction?

Disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, malfunctioning prostetic valves/ECMO, and RBC infections

3. A peripheral blood smear stained with Giemsa is shown below (in document). It is most likely from which one of the following persons? A. A 32 year old man with Crohn's disease involving the terminal ileum. B. A 51 year old man who drinks large amounts of alcohol daily. C. A 27 year old woman who had pigmented gallstones at cholecystectomy. D. A 39 year old woman who follows a strict vegan diet. E. A 41 year old woman who has had five full term pregnancies.

E

What is hereditary elliptocytosis?

Ellipses shaped RBCs.

What are the 2 steps to thrombopoiesis before platelet production?

Endomitotic synchronous nuclear replication and cytoplasmic granulation.

What are some iron-rich foods containing non-heme iron?

Enriched breakfast cereals, cooking beans and lentils, canned beans, pumpkin seeds, molasses, baked potato with skin, enriched pasta, canned asparagus.

What are there adipocytes in the bone marrow?

Fat is a source of nutrition in the bone marrow.

What are the 8 types of blood cells outside of the bone marrow?

From Myeloid Precursors: Neutrophils (from bands), Eosinophils, Basophils, and Monocytes/Macrophages. From Erythroid Progenitors: Reticulocytes and Erythrocytes. From Megakaryoctyes: Platelets.

What is one example of an RBC enzyme deficiency?

G6PD Deficiency

What are some causes of lymphopenia?

HIV/AIDS (hypergammaglobulinemia), corticosteroids, immunosuppressives, chemotherapy, EBV/CMV, Hodgkins lymphoma

How is hematocrit calculated?

Hematocrit is the % of packed RBCs/Total (RBCs + Buffy Coat/WBCs + Plasma). It should be 36-45% in women, 43-50% in men. Measuring hemoglobin concentration is more accurate.

What is iron found in?

Heme, surrounded by a protophorphrin ring.

Describe hepcidin.

Hepcidin regulates iron levels; it is excreted by the liver, circulates in the serum, and is excreted in the urine. It regulates Ferroportin, the protein that exports iron from duodenal and macrophage cells to the blood stream, by internalizing and degrading it so that iron absorption and release from stores ceases. It reduces iron available in the blood to bacteria during infection. Hepcidin is induced in the liver via HFE, TRF2, and HJV. It is responsive to hypoxia, iron stores, iron intake, erythropoiesis, and inflammation. Erythroferrone down regulates hepcidin in stress erythropoiesis. Reduced hepcidin expression can result in hemochromatosis, as in genetic dysregulation.

What does iron deficiency anemia look like on a peripheral blood smear?

Hypochromic, microcytic.

How is the kidney involved in erythropoiesis?

Hypoxia induces HIF which stimulate erythropoietin production in the kidney and acts on pronomoblasts.

Describe the direct and indirect Coombs tests.

In the direct Coombs test, the patients RBCs are incubated with antihuman antibodies and they agglutinate. In the indirect Coombs test, the patients serum is introduced to a donor blood sample and the antibodies complex with the RBCs. Antihuman antibodies are added and they agglutinate.

How is iron absorbed?

In the duodenum, ferric (Fe3+) is reduced to ferrous (Fe2+) by ferric reductase at the apical side of the duodenal enterocyte. Ferrous iron enters the cell via DMT-1 (divalent metal transporter). Some is stored in the cell with ferritin, some exits into the blood stream via ferroportin. It travels in the blood stream as 2 atoms of ferric iron bound to transferrin, to the site of use or storage (i.e. in liver or heart as ferritin).

Where are the majority of RBCs made in adults?

In the iliac crests.

What are 5 signs of hemolysis?

Increased in lactate dehydrogenase (LDH), increase in indirect bilirubin, increased in reticulocytes, increased urine hemosiderin, and decrease haptoglobin.

What are the 2 types of hemolysis?

Intravascular (blood vessels) or extravascular (spleen)

How is iron deficiency anemia distinguished from anemia of chronic disease?

Iron deficiency anemia is decreased serum iron and ferritin, increased transferrin. Anemia of chronic disease is decreased serum iron and transferrin, increased ferritin.

What is the most common causes of anemia in the world (in order)?

Iron deficiency, hookworm, sickle cell/Thalassemia, malaria.

What is the first step to figuring out the type of hemolysis?

Is it Coombs positive or is it Coombs negative (aka are there antibodies to RBCs or not)

What is MCV (mean corpuscular volume)?

It is the size of the average red blood cell. Normal is 85-100 MCV. Bigger is macrocytosis and lower is microcytosis.

LECTURE 1: HEMATOPOIESIS AND LEUKOCYTE DISORDERS

LECTURE OBJECTIVES: Basic knowledge of blood cell function and morphology is essential for physicians. Blood cell production is regulated through negative feedback mechanisms. Blood diseases arise from abnormal cell quantity or function.

What is the clinical presentation of iron deficiency anemia?

Lethargy, irritability, pallor, with history of poor iron intake (i.e. heavy menses, blood in stool, frequent epistaxis). Iron malabsorption can be a sign of another disease (i.e. Celiac or autoimmune gastritis).

What are the cutoffs for Leukopenia? Neutropenia? Lymphopenia?

Leukopenia: WBC <3,000 Neutropenia: ANC <1,500 (Severe <500, Very Severe <100) Lymphopenia: ALC <1,200

What are 2 types of acquired Coombs negative disease?

Mechanical destruction and acquired RBC defect

Describe monocytes.

Monocytes are in the blood, and become macrophages in target tissues (i.e. Langerhan cells in skin, Kupfer cells in the liver). They are phagocytes and antigen presenting cells. They have a purple cytoplasm, with scant granules and vacuoles, an "ugly" or kidney shaped nucleus, and lacy chromatin.

Besides the blood, what 2 organs require heme for what molecules?

Muscle for myoglobin and liver for cytochrome.

What is the myelopoiesis of neutrophils?

Myeloblast > promyelocyte > myelocyte > metamyelocyte > band > neutrophil

What are some causes of eosinophilia?

Neoplasia, allergy, Addisons disease, Collagen-Vascular disease, parasite infection

LECTURE 2: IRON DEFICIENCY, IRON OVERLOAD, ANEMIA OF CHRONIC INFLAMMATION

OBJECTIVES: 1) Describe the mechanism by which iron enters the body and is transported to sites of utilization and/or storage 2) Discuss the regulatory proteins involved in iron homeostasis in the body. 3) Identify pertinent features of iron deficiency anemia, iron-deprived erythropoiesis and iron overload.

What are 2 types of acquired RBC defect?

Paroxysmal nocturnal hemoglobinuria and vitamin B12/folate deficiency

What are some rare leukocyte disorders?

Pelger-Hüet abnormality May-Hegglin anomaly Chediak-Higashi Chronic granulomatous disease Bruton's agammaglobuinamia Severe combined immunodeficiencies

Describe platelets.

Platelets are anucleate and a key component of hemostasis (clotting) with their procoagulant granules. Their production is driven by thrombopoietin and they bind to damaged endothelium via von Willebrand factor.

What is the sequence of erythropoiesis?

Pronormoblast > basophilic pronomoblast > polychromatophilic pronomoblast > orthochromic pronomoblast (pyknotic) > reticulocyte

What are Ankyrin and Spectrin?

Proteins in the RBC cytoskelen that attach it to the membrane creating and supporting the biconcave disk shape.

What are 3 types of inherited Coombs negative disease?

RBC enzyme deficiency, hemoglobinopathy, and RBC structure disorder

What are the 3 cellular components of blood, in order of quantity?

Red blood cells, platelets, and white blood cells

What is the function of RBCs?

Respiration. Delivery of oxygen, removal of CO2.

Describe erythrocytes and reticulocytes.

Reticulocytes make RBCs and are blue/purple because of DNA/RNA. Reticulocytes are .5-1.5% of the RBC population and are increased in anemia. Erythrocytes are anucleate sacks of hemoglobin shaped as a biconcave disk and live for 120 days. Their production is driven by erythropoietin.

What are some causes of neutropenia?

Sepsis, HIV/AIDS, marrow infiltration of infection, chemotherapy, immunosuppressants, antibiotics, leukemias, myelodysplastic syndromes, Fetty's syndrome, Systemic Lupus Erythematosus, ethnic (benign nuetropenia), Elastase mutation

How are body iron stores measured?

Serum Ferritin is measured as an indicator of body iron stores. It goes up with hemochromatosis and as a acute phase reactive with tissue injury. In iron overload, ferritin complexes to form Hemosiderin in cells.

What are 2 types of hemoglobinopathies?

Sickle cell disease and thalassemias

What are some distinguishing features of hematopoiesis?

Size is inversely proportional to maturity, chromatin condenses with maturity, N:C ratio, nuclear shape and location, color and size of granules, color and shape of cytoplasm.

What is hereditary spherocytosiss?

Spherically shaped RBCs. Inflexibility can trap them in circulation and cause anemia. Pathophysiology: Spectrin or akyrin deficiency creates spherocytes which are trapped in the spleen and hemolysed by splenic macrophages in 30-60 days.

What are 2 types of RBC structure disorder?

Spherocytosis and Elliptocytosis

Why is spinach not a great source of iron?

Spinach is non-Heme iron which is less readily absorbed, bioavailability prevented by fiber, Ca2+, etc. Heme iron (i.e. meat) is more readily absorbed.

What are causes of anemia intrinsic to the RBC?

Synthesis of hemoglobin (nutrient deficiency in iron, folate, or vitamin B12, hemoglobinoapthy/thalassemia, porphyrias), red cell membrane disorders, red cell enzyme disorders. Often a component of decreased production as well as increased destruction.

What is the ontogeny of the lymphoid progenitor?

T cells become CD4 helper and CD8 killer cells. B cells become plasma cells. And there are natural killer cells.

What 2 other conditions are on the differential with iron deficiency anemia?

Thalassemia and Anemia of Chronic Disease.

What are the 4 types of cells in the bone marrow?

The 3 myeloid progenitors: myeloid precursors, erythroid progenitors, and megakaryocytes, and the lymphoid progenitors.

Describe neutrophils.

The most numerous leukocytes, they are also called PMNs with a segmented nucleus. They are the primary defense against infections and phagocytes, killing with toxic oxygen species and toxic proteins. They have pink cytoplasm with multiple purple granules and 3-4 nuclear segments with strands connecting nuclear lobes.

What does IgM mediated or cold hemolysis look like on a peripheral blood smear?

There is agglutination

Describe eosinophils.

They are a minor component of blood. They have granules filled with vasoactive compounds and are also phagocytes. They are mediators of allergy and thought to fight parasites. They had cytoplasm filled with red granules and a bilobed nucleus.

Describe lymphocytes.

They are the 2nd most numerous leukocyte. They make antibodies (B cells), destroy virus infected or cancer cells (killer T cells), and coordinate immune response (helper T cells). They have a small purple cytoplasm and a big circular monolobated nucleus. They have no granules and are small.

How is platelet production regulated?

Thrombopoietin, made in the liver and kidney, binds platelets and megakaryocytes which regulates steady state of platelet production. In megakaryocyte hypoplasia and thrombocytopenia, thrombopoietin in the plasma is increased. It is decreased in megakaryocyte hyperplasia and thrombocytosis.

Where does the majority of ingested iron go?

To erythropoiesis

How is transferrin measured clinically?

Transferrin is measured clinically as Total Iron Binding Capacity (TIBC). Transferrin saturation is normally 20-50%.

What is pathophysiology of transfusion-related hemochromatosis?

Transfused RBC iron is retained without mechanism for iron egress from the body. Chronic transfusions (i.e. Beta Thalassemia Major) can cause this.

What is the phenotype of hemochromatosis? What is the treatment?

Vertigo, hair loss, memory loss, bronze skin, heart degeneration, hepatomegaly and cirrhosis, diabetes, testicular atrophy, and arthritis Treatment: Regular phlebotomy

What enhances absorption of iron?

Vitamin C, sugar, acid, and ethanol

What is included in a CBC (Complete Blood Count)?

WBCS, hemoglobin, hematocrit, platelets, and MCV.

Describe warm and cold antibodies.

Warm antibodies are IgG mediated, occasionally fix complement, and show extravascular hemolysis. Cold antibodies are IgM mediated, fix complement, and show intravascular hemolysis as well.

What are some causes of warm and cold antibody mediated hemolytic anemia?

Warm is uncommon and often idiopathic. The causes included Hepatits C, autoimmune diseases, and lymphomas. Cold is rare and rarely idiopathic. The causes include mycoplasma, CBV/CMV mononucleosis, and lymphomas.

What are the treatments for antibody mediated hemolytic anemias?

Warm: Corticosteroids as first line and rituximab or splenectomy as second line. Cold: Rituximab and plasma exchange. *For both, always treat the underlying disorder.*

What is the who, what when, where, why of G6PD deficiency?

Who: Men (X-linked) What: Oxidative stress When: Triggered by fava beans, infections, diabetic ketoacidosis, anti-malarials, sulfa medications, aspirin, methylene blue Where: Africa, Mediterranean Why: Resistance to malaria

What does Glucose-6-Phosphate Dehydrogenase do?

Within the glucose to ribose 5-phosphate pathway, it converts oxidative toxic products to non-toxic products under oxidative stress.

SUMMARY: IRON DEFICIENCY AND OVERLOAD

•Iron is essential for every cell •Dietary Iron Deficiency Anemia is a global health problem •Iron in the body is controlled by absorption / duodenum -Regulated by Hepcidin -No normal mechanism for iron to leave body •Hepcidin -Genetic defects in synthesis cause hemochromatosis -Increase with inflammation causes iron to become unavailable; anemia of chronic inflammation

LECTURE 3: HEMOLYTIC ANEMIAS

•Many inherited and acquired diseases cause early erythrocyte destruction (< 120 days). •Coombs testing shows whether hemolysis is due to antibodies against red blood cells. •Hemolysis is diagnosed with: indirect bilirubin, LDH, reticulocytes and haptoglobin. •The smear provides crucial cues to the type of hemolysis.