1. Diseases of Blood Cells

2. Back to Basics Blood is a liquid tissue A mixture of cells and water
The water contains
Protein, glucose, cholesterol, calcium, hormones, metabolic waste and hundreds of other substances
Plasma is the liquid portion of the blood containing the blood clotting protein Fibrinogen
Serum is the fluid remaining after the blood clots
Does not contain Fibrinogen

3. plasma (55%)
red blood cells
(5-6-million /ml)
white blood cells
(5000/ml)
platelets

4. Plasma
liquid part of blood
plasma transports:-
soluble food molecules
waste products
hormones
antibodies

5. Platelets
if you get cut:-
platelets produce
tiny fibrin threads
these form a web-like
mesh that traps blood
cells.
these harden forming a clot, or "scab."
150,000 to 400,000 per mm3

6. Physical Characteristics of Blood
Average volume of blood:
5–6 L for males; 4–5 L for females (Normovolemia)
Hypovolemia - low blood volume
Hypervolemia - high blood volume
Viscosity (thickness) (where water = 1)
The pH of blood is 7.35–7.45; x = 7.4
Osmolarity = 300 mOsm or 0.3 Osm
This value reflects the concentration of solutes in the plasma
Salinity = 0.85%
Reflects the concentration of NaCl in the blood
Temperature is 38C, slightly higher than “normal” body temperature
Blood accounts for approximately 8% of body weight

7. Composition of Blood 2 major components Liquid = plasma (55%)
Formed elements (45%)
Erythrocytes, or red blood cells (RBCs)
Leukocytes, or white blood cells (WBCs)
Platelets - fragments of megakaryocytes in marrow

9. Blood Plasma Blood plasma components: Water = 90-92% Proteins = 6-8%
Albumins; maintain osmotic pressure of the blood
Globulins
Alpha and beta globulins are used for transport purposes
Gamma globulins are the immunoglobulins (IgG, IgA, etc)
Fibrinogen; a clotting protein
Organic nutrients – glucose, carbohydrates, amino acids
Electrolytes – sodium, potassium, calcium, chloride, bicarbonate
Nonprotein nitrogenous substances – lactic acid, urea, creatinine
Respiratory gases – oxygen and carbon dioxide

10. Laboratory Assessment of Blood Cells
Complete Blood Count (CBC) includes
White Blood Cell Count (WBC)
Red Blood Cell Count (RBC)
Percentage of white cells that are neutrophils, eosinophis or basophils (white cell differential count)
Amount of hemoglobin
Hematocrit
Percent of blood volume occupied by red blood cells

11. Red Cell Indices Mean Cell Volume (MCV) Average size of a RBC
Mean Cell Hemoglobin (MCH)
Average amount of hemoglobin per RBC
Mean Corpuscular Hemoglobin Concentration (MCHC)
Average concentration of hemoglobin in all RBCs

12. Red Cell Indices Used to Diagnose Disease
Macrocytic
Red Blood Cells may be too large
Microcytic
Red Blood Cells may be too small
Normocytic
Red Blood Cells are normal size
Hypochromic
Too little hemoglobin
Normochromic
Normal amount of hemoglobin
Normochromic
Normal amount of hemoglobin

13. Normochromic

14. Macrocytic
Red Blood Cells may be too large

15. Macrocytic

16. The RBC's here are smaller than normal and have an increased zone of central pallor. This is indicative of a hypochromic (less hemoglobin in each RBC) microcytic (smaller size of each RBC) anemia. There is also increased anisocytosis (variation in size) and poikilocytosis (variation in shape).

17. Microcytic

18. The most common cause for a hypochromic microcytic anemia is iron deficiency. The most common nutritional deficiency is lack of dietary iron. Thus, iron deficiency anemia is common. Persons most at risk are children and women in reproductive years (from menstrual blood loss and from pregnancy).

19. the RBC size remains normal, whereas the overall volume of the haemoglobin is found below the healthy minimum of 11.

20. Not enough hemoglobin - hypochromic

21. Erythrocytes (RBCs) Biconcave disc
Folding increases surface area (30% more surface area)
Plasma membrane contains spectrin
Give erythrocytes their flexibility
Anucleate, no centrioles, no organelles
End result - no cell division
No mitochondria means they generate ATP anaerobically
Prevents consumption of O2 being transported
Filled with hemoglobin (Hb) - 97% of cell contents
Hb functions in gas transport
Hb + O HbO2 (oxyhemoglobin)
Most numerous of the formed elements
Females: 4.3–5.2 million cells/cubic millimeter
Males: 5.2–5.8 million cells/cubic millimeter

22. Erythrocytes (RBCs)
Figure 17.3

23. Erythrocyte Function
Erythrocytes are dedicated to respiratory gas transport
Hemoglobin reversibly binds with oxygen and most oxygen in the blood is bound to hemoglobin
Composition of hemoglobin
A protein called globin
made up of two alpha and two beta chains
A heme molecule
Each heme group bears an atom of iron, which can bind to one oxygen molecule
Each hemoglobin molecule thus can transport four molecules of oxygen

24. Structure of Hemoglobin
Figure 17.4

25. Hemoglobin Oxyhemoglobin – hemoglobin bound to oxygen
Oxygen loading takes place in the lungs
Deoxyhemoglobin – hemoglobin after oxygen diffuses into tissues (reduced Hb)
Carbaminohemoglobin – hemoglobin bound to carbon dioxide
Carbon dioxide loading takes place in the tissues

26. Life Cycle of Red Blood Cells

27. Fate and Destruction of Erythrocytes
The life span of an erythrocyte is 100–120 days
Travels about 750 miles in that time (LA to Albuquerque)
Old erythrocytes become rigid and fragile, and their hemoglobin begins to degenerate
Dying erythrocytes are engulfed by macrophages
Heme and globin are separated
Iron is removed from the heme and salvaged for reuse
Stored as hemosiderin or ferritin in tissues
Transported in plasma by beta-globulins as transferrin

28. Fate and Destruction of Erythrocytes
Heme is degraded to a yellow pigment called bilirubin
Liver secretes bilirubin into the intestines as bile
Intestines metabolize bilirubin into urobilinogen
Urobilinogen leaves the body in feces, in a pigment called stercobilin
Globin is metabolized into amino acids which are then released into the circulation

29. Figure 17.9

30. Production of Erythrocytes
Hematopoiesis – blood cell formation
Occurs in the red bone marrow (myeloid tissue)
Axial skeleton and girdles
Epiphyses of the humerus and femur
Marrow contains immature erythrocytes
Composed of reticular connective tissue
Hemocytoblasts give rise to ALL formed elements
Lymphoid stem cells - give rise to lymphocytes
Myeloid stem cells - give rise to all other blood cells

31. Production of Erythrocytes: Erythropoiesis
A hemocytoblast is transformed into a committed cell called the proerythroblast
Proerythroblasts develop into early erythroblasts
The developmental pathway consists of three phases
Phase 1 – ribosome synthesis in early erythroblasts
Phase 2 – hemoglobin accumulation in late erythroblasts and normoblasts
Phase 3 – ejection of the nucleus from normoblasts and formation of reticulocytes
Reticulocytes then become mature erythrocytes
Reticulocytes make up about 1 -2 % of all circulating erythrocytes

32. Production of Erythrocytes: Erythropoiesis

33. Regulation and Requirements for Erythropoiesis
Circulating erythrocytes – the number remains constant and reflects a balance between RBC production and destruction
Too few red blood cells leads to tissue hypoxia
Too many red blood cells causes an undesirable increase in blood viscosity
Erythropoiesis is hormonally controlled and depends on adequate supplies of iron, amino acids, and B vitamins

34. Hormonal Control of Erythropoiesis
Erythropoietin (EPO) released by the kidneys is triggered by:
Hypoxia due to decreased RBCs
Decreased oxygen availability
Increased tissue demand for oxygen
Enhanced erythropoiesis increases the:
RBC count in circulating blood
Oxygen carrying ability of the blood

35. Erythropoietin Mechanism
Imbalance
Start
Normal blood oxygen levels
Stimulus: Hypoxia due to decreased RBC count, decreased availability of O2 to blood, or increased tissue demands for O2
Imbalance
Increases O2-carrying ability of blood
Reduces O2 levels in blood
Erythropoietin stimulates red bone marrow
Kidney (and liver to a smaller extent) releases erythropoietin
Enhanced erythropoiesis increases RBC count

36. An Electronmicrograph of a Platelet

37. Dietary Requirements of Erythropoiesis
Erythropoiesis requires:
Proteins, lipids, and carbohydrates
Iron, vitamin B12, and folic acid
The body stores iron in Hb (65%), the liver, spleen, and bone marrow
Intracellular iron is stored in protein-iron complexes such as ferritin and hemosiderin
Circulating iron is loosely bound to the transport protein transferrin

38. Anemia ?
Production?
Survival/Destruction?

39. Causes of Anemia Decreased erythrocyte production
Decreased erythropoietin production
Inadequate marrow response to erythropoietin
Erythrocyte loss
Hemorrhage
Hemolysis

40. Erythrocyte Disorders
Polycythemia
Abnormal excess of erythrocytes
Increases viscosity, decreases flow rate of blood
Anemia
Abnormally low hemoglobin in blood
Caused by decreased numbers of RBC’s, decreased amount of hemoglobin in RBC’s, or both

41. Anemia Anemia – blood has abnormally low oxygen-carrying capacity
It is a symptom rather than a disease itself
Due to some underlying condition
Blood oxygen levels cannot support normal metabolism
Signs/symptoms include fatigue, paleness, shortness of breath, and chills

42. Morphological Approach (big versus little)
First, measure the size of the RBCs:
Use of volume-sensitive automated blood cell counters, such as the Coulter counter. The red cells pass through a small aperture and generate a signal directly proportional to their volume.
Other automated counters measure red blood cell volume by means of techniques that measure refracted, diffracted, or scattered light
By calculation from an independently-measured red blood cell count and hematocrit:
MCV  (femtoliters) = 10 x HCT(percent) ÷ RBC (millions/µL)

43. Diagnosis of Anemia CBC and Determination of Red Blood Cell Indices
Different types of Anemia are generally characterized by red blood cells of a certain size
For Example, small (microcytic, low MCV) RBCs occur with iron deficiency
RBCs contain less hemoglobin and are pale (hypochromic, low MCHC)

44. Underproduction (morphological approach)
MCV>115
B12, Folate
Drugs that impair DNA synthesis (AZT (Zidovudine, chemo)
MDS (myelodysplastic syndromes)
Ineffective production (or dysplasia) of the myeloid class of blood cells
MCV =
Ditto
Endocrinopathy (hypothyroidism)
Reticulocytosis
Increased number of immature RBCs

45. Underproduction Microcytic Iron deficiency Thalassemia trait
abnormal form of hemoglobin
Anemia due to chronic disease (30-40%)
Sideroblastic anemia
bone marrow produces ringed sideroblasts rather than healthy RBCs
Normocytic
Anemia from a chronic disease
Renal failure

47. Petechial Hemorrhages on the Heart found when a coagulopathy is due to a low platelet count. They can also appear following sudden hypoxia.

48. Ecchymoses are larger than petechiae
Ecchymoses are larger than petechiae. In between in size are hemorrhages called purpura.

49. A localized collection of blood outside the vascular system within tissues is known as a hematoma

50. Review red blood cell disorders
Marrow production
Thalassemias
Myelodysplasia
Myelophthisic
Aplastic anemia
Nutritional deficiencies
Red cell destruction
Hemoglobinopathies
Enzymopathies
Membrane disorders
Autoimmune

51. Thalassemia Genetic defect in hemoglobin synthesis
 synthesis of one of the 2 globin chains ( or )
Imbalance of globin chain synthesis leads to depression of hemoglobin production and precipitation of excess globin (toxic)
“Ineffective erythropoiesis”
Ranges in severity from asymptomatic to incompatible with life (hydrops fetalis)
Found in people of African, Asian, and Mediterranean heritage

52. Alpha Thalassemia
This is alpha thalassemia major. There have been two major variations of alpha thalassemia arise in human history. One variation, most prevalent in Southeast Asia, is known as alpha thalassemia 1. In this variant, two alpha globin genes are deleted on one chromosome 16. The other variant, known as alpha thalassemia 2, is most common in Africa and the Mediterranean region, and differs in that a single alpha globin gene is missing from one chromosome 16. Alpha thalassemia 1, with alpha globin gene deletions on a single chromosome 16, can give rise to alpha thalassemia major in the homozygous state, when both chromosomes are affected. Affected persons become anemic in utero, because even fetal hemoglobin cannot be produced, and severe hydrops fetalis results, which leads to stillbirth, or death soon after birth from pulmonary hypoplasia or cardiac failure. Hemoglobin electrophoresis will reveal affected fetuses or neonates to have about 80% hemoglobin Barts (a tetramer of gamma chains) and about 20% hemoglobin Portland (or sometimes hemoglobin Gower 1) normally present only in embryonic life in the first trimester. RBCs that contain mostly hemoglobin Barts have marked anisocytosis and poikilocytosis, and there is expansion of erythropoiesis with many immature RBCs in the peripheral blood, as evidenced by polychromasia, nucleated RBCs and even erythroblasts as shown here.

53. Thalassemias Dx: Smear: microcytic/hypochromic, misshapen RBCs
-thalassemia will have an abnormal Hgb electrophoresis (HbA2, HbF)
The more severe -thalassemia syndrome can have HbH inclusions in RBCs
Fe stores are usually elevated

54. Thalassemia
The oxygen depletion in the body becomes apparent within the first 6 months of life.
If left untreated, death usually results within a few years.
Note the small, pale (hypochromic), abnormally-shaped red blood cells. The darker cells likely represent normal RBCs from a blood transfusion.

55. Thalassemia
The only treatments are stem cell transplant and simple transfusion.
Chelation therapy to avoid iron overload has to be started early.

57. Marrow Production - Myelodysplasia
Used to be referred to as “Preleukemia”
Most commonly in the elderly.
Occurs when something goes wrong in your bone marrow

58. Signs and Symptoms of Myelodysplasia
Fatigue
Shortness of breath
Unusual paleness (pallor) due to anemia
Easy or unusual bruising or bleeding
Pinpoint-sized red spots just beneath your skin caused by bleeding (petechiae)
Frequent infections

59. Causes
Caused by poorly formed or dysfunctional blood cells due to either
Unknown causes
Chemical exposure

60. Myelodysplasia

61. Marrow Production - Myelophthisic
Myelophthisic anemia is a normocytic-normochromic anemia that occurs when normal marrow space is infiltrated and replaced by nonhematopoietic or abnormal cells.
Causes:
Most often due to replacement of the bone marrow by metastatic cancers such as breast or prostate; less often, kidney, lung, adrenal, or thyroid.
Marrow fibrosis often occurs.
Splenomegaly may develop.

62. Myelophthisic

63. Marrow Production - Aplastic Anemia
The body stops producing enough new blood cells.
Signs and symptoms may include:
Fatigue
Shortness of breath with exertion
Rapid or irregular heart rate
Pale skin
Frequent or prolonged infections
Unexplained or easy bruising
Nosebleeds and bleeding gums
Prolonged bleeding from cuts
Skin rash
Dizziness
Headache

64. NORMAL BONE MARROW

65. Here we see a sample of bone marrow in a patient with Aplastic Anaemia
Here we see a sample of bone marrow in a patient with Aplastic Anaemia. Notice there are very few cells except for the fat cells

66. Factors that can temporarily or permanently injure bone marrow and affect blood cell production include:
Acquired
Radiation and chemotherapy treatments
Exposure to toxic chemicals.
Exposure to benzene
Use of certain drugs even some antibiotics.
Autoimmune disorders
Viral infections
Epstein Barr, CMV, Parvovirus B19, HIV
Pregnancy.
Unknown factors. This is called idiopathic aplastic anemia.

67. Marrow Production - Aplastic Anemia
Hereditary
Fanconi
a rare, inherited blood disorder that leads to bone marrow failure.
Diamond-Shwachman
a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction

68. Marrow Production - Aplastic Anemia
Treatment
Most patients require red cell transfusions.
Bone MarrowTransplant when possible.
Stem Cell Transplant
Medication: Bone Marrow Stimulants
Sargramostim (Leukine)
Filgrastim (Neupogen)
Pegfilgrastim (Neulasta)
Epoetin alfa (Epogen, Procrit)

69. Hemolytic Anemia – RBC Destruction
Hemolytic anemias are either acquired or congenital.
Hemolytic anemia is a condition in which there are not enough RBCs in the blood
Due to premature RBC destruction
Hemolytic anemia can result from:
infection
certain drugs
autoimmune disorders in which the body attacks and destroys its own red blood cells
inherited disorders such as sickle cell anemia or thalassemia.

70. Hemolytic anemias

71. Symptoms of Hemolytic Anemia
Dark Urine
Enlarged spleen
Fatigue
Fever
Pale skins color
Rapid heart rate
Shortness of breath
Yellow skin color (jaundice)
Chills

72. Sickle Cell Anemia
Single base pair mutation results in a single amino acid change.
Under low oxygen, Hgb becomes insoluble forming long polymers
This leads to membrane changes (“sickling”) and vasoocclusion

76. Red Blood Cells from Sickle Cell Anemia
Deoxygenation of SS erythrocytes leads to intracellular hemoglobin polymerization, loss of deformability and changes in cell morphology.
OXY-STATE
DEOXY-STATE

77. Transfusion in Sickle Cell (Controversy!)
Used correctly, transfusion can prevent organ damage and save the lives of sickle cell disease patients.
Used unwisely, transfusion therapy can result in serious complications.

78. Transfusion in Sickle Cell (Controversy!)
Simple transfusion – give blood
Partial exchange transfusion - remove blood and give blood
Erythrocytapheresis – use apheresis to maximize blood exchange
When to use each method?

79. Transfusion in Sickle Cell
In general, patients should be transfused if there is sufficient physiological derangement to result in heart failure, dyspnea, hypotension, or marked fatigue.
Tends to occur during an acute illness or when hemoglobin falls under 5 g/dL.

80. Transfusion in Sickle Cell (exchange transfusion)
Bleed one unit (500 ml), infuse 500 ml of saline
Bleed a second unit and infuse two units.
Repeat. If the patient has a large blood mass, do it again.

81. Transfusion in Sickle Cell (chronic transfusion therapy)
Stroke
Chronic debilitating pain
Pulmonary hypertension
Setting of renal failure and heart failure

82. Transfusion in Sickle Cell (chronic transfusion therapy)
Controversial uses:
Prior to contast media exposure
Sub-clinical neurological damage
Priapism
Leg Ulcers
Pregnancy

83. Pernicious Anemia
Pernicious anemia is a decrease in red blood cells that occurs when the body cannot properly absorb vitamin B12 from the GI Tract
Common causes include:
Weakened stomach lining (atrophic gastritis)
The body's immune system attacking the cells that make intrinsic factor (autoimmunity against gastric parietal cells) or intrinsic factor itself

84. Symptoms Diarrhea or constipation Fatigue Loss of appetite Pale skin
Shortness of breath, mostly during exercise
Swollen, red tongue or bleeding gums
Nerve damage

85. Red cell destruction Elevated reticulocyte count Mechanical Autoimmune
Drug
Congenital

89. Red cell destruction – membrane disorders
Hereditary spherocytosis
Hereditary elliptocytosis
Hereditary pyropoikilocytosis
Southeast Asian ovalocytosis

90. Review red blood cell disorders Red cell destruction – membrane disorders

91. Review red blood cell disorders Red cell destruction – enzymopathies
G6PD deficiency
Pyruvate kinase deficiency
Other very rare deficiencies

92. Deoxyhemoglobin S Polymer Structure
A) Deoxyhemoglobin S
14-stranded polymer
(electron micrograph)
B) Paired strands of
deoxyhemoglobin S
(crystal structure)
C) Hydrophobic pocket
for 6b Val
D) Charge and size prevent
6b Glu from binding.
Dykes, Nature 1978; JMB 1979
Crepeau, PNAS 1981
Wishner, JMB 1975

93. Transfusion in Sickle Cell
In severely anemic patients, simple transfusions should be used.
Common causes of acute anemia:
acute splenic sequestration
transient red cell aplasia
Hyperhemolysis (infection, acute chest syndrome, malaria).
If the patient is stable and the reticulocyte count high, transfusions can (and should) be deferred.

94. Transfusion in Sickle Cell (exchange transfusion)
A comprehensive transfusion protocol should include accurate records of the patient’s red cell phenotype, alloimmunization history, number of units received, serial Hb S percentages, and results of monitoring for infectious diseases and iron overload.
Transfusions are used to raise the oxygen-carrying capacity of blood and decrease the proportion of sickle red cells.

95. Transfusion in Sickle Cell (exchange transfusion)
Transfusions usually fall into two categories:
episodic, acute transfusions to stabilize or reverse complications.
long-term, prophylactic transfusions to prevent future complications.

96. Transfusion in Sickle Cell (exchange transfusion)
episodic, acute transfusions to stabilize or reverse complications.
Limited studies have shown that aggressive transfusion (get Hgb S < 30%) may help in sudden severe illness.
May be useful before general anesthesia.
Vichinsky et al., NEJM 1995

97. Transfusion in Sickle Cell
Inappropriate uses of transfusion:
Chronic steady-state anemia
Uncomplicated pain episodes
Infection
Minor surgery
Uncomplicated pregnancies
Aseptoic necrosis

98. Transfusion in Sickle Cell (exchange transfusion)
Except in severe anemia, exchange transfusion offers many benefits and is our first choice
Phenotypically matched, leukodepleted packed cells are the blood product of choice.
A posttransfusion hematocrit of 36 percent or less is recommended.
Avoid hyperviscosity, which is dangerous to sickle cell patients.

99. Iron overload and chelation
Can occur in any patient requiring chronic transfusion therapy or in hemochromatosis.
Liver biopsy is the most accurate test though MRI is being investigated.
Ferritin is a good starting test.
120 cc of red cells/kg of body weight is an approximate point at which to think about iron overload

100. Iron overload and chelation
Chelator, deferoxamine
25 mg/kg sq per day over 8 hours.
Supplementation with vitamin C may aid excretion.
Otooxicity, eye toxicity, allergic reactions.
Discontinue during an infection.
Oral chelators are in development.

101. Conclusions
Transfuse for any severe anemia with physiologic compromise.
Decide early whether transfusion will be rare or part of therapy.
Avoid long-term complications by working with your blood bank and using chelation theraoy.

102. Anemia: Insufficient Erythrocytes
Hemorrhagic anemia – result of acute or chronic loss of blood
Hemolytic anemia – prematurely ruptured erythrocytes
Aplastic anemia – destruction or inhibition of red bone marrow