Exam 4: Hematologic

Question 1

structure of hemoglobin

Answer 1

o each hgb molecule is composed of two pairs of polypeptide chains (the globins)
- 2 alpha
- 2 beta
**within every chain there is a heme chain, where it binds to iron ion

o four colorful complexes of iron plus protoporphyrin (the hemes)
 responsible for blood’s ruby-red color and oxygen-carrying capacity

Question 2

what is oxyhemoglobin

Answer 2

Hgb picks up oxygen in the lungs and binds it to the iron ions

Question 3

what is deoxyhemoglobin

Answer 3

delivers oxygen to body tissues, becoming darker red

Question 4

how many O2 molecules are carried for every hgb?

Answer 4

four

Question 5

RBC structure: HbA

Answer 5

o 2 alpha, 2 beta chains
o Major adult Hgb
o About 97%
* most common

Question 6

RBC structure: HbA2

Answer 6

o We don’t know significance of having HbA2
o 2 alpha, 2 delta chains
o Minor adult Hgb
o About 2-3%

Question 7

RBC structure: HbF

Answer 7

o Major fetal Hgb: The majority of Hgb when we’re born, completely replaced by HgbA by six months of life
o Increased affinity to O2
o 2 alpha, 2 gamma chains

Question 8

RBC structure: Hgb S

Answer 8

o Quality dysfunction of beta (sickle trait/disease)
o Adult hgb -> HbF turns into HbS after 6months of age

Question 9

what happens to hgb after death?

Answer 9

o After 120 days, macrophages degrade erythrocyte
o Globin (the protein part of Hgb- the alpha/beta) is broken down into amino acids  sent back to bone marrow ->alpha and beta chains are removed by kidneys
o Iron in heme portion is;
 ->stored in liver or spleen, as ferritin OR
 -> returned to red bone marrow
o Non-iron portion of heme is degraded to biliverdin  bilirubin -> liver ->secreted as bile -> excreted in feces and urine

Question 10

normal values: RBC

Answer 10

4.5-6

Question 11

normal value: Hgb

Answer 11

o >13 in men, >12 in women
o The measurement of mass hgb

Question 12

normal values: Hct

Answer 12

o 40-50 in men, 35-45 in women, USUALLY 3X HGB AMT
o Physical amount of space that the hgb occupies as a percentage of the whole that red cells occupy

Question 13

normal values: Mean Corpuscular Volume (MCV)

Answer 13

o 80-100 fl
o measurement of the average volume of an RBC
 [tells you if RBC size is small, normal, or large- each one of these have diff kind of anemias]
o Used as a guide NOT to diagnose- should not be used to rule in or out a specific course of anemia!!
 This is why—just because you have microcytic anemia, doesn’t mean you don’t have macrocytic.

Question 14

COLOR: Mean Corpuscular Hgb (MCH)

Answer 14

o 27-31
o Measurement for the amount of hgb per RBC
 LOW means- pallor

Question 15

COLOR: Mean Corpuscular Hgb Concentration (MCHC)

Answer 15

o 32-36
o Measurement of hgb concentration per RBC
 Deficient in iron, therefore will be pallor looking
 hypochromic anemia most commonly seen in iron deficient anemia

Question 16

SIZE: RBC Distribution Width (RDW)

Answer 16

o An index of variation in RBC size and shape
 Normally RBC size will differ by 11.5-15%
 >15% = indicates cells differing in size – smaller or larger – when compared with older cells
* Indicates an evolving microcytic or macrocytic anemia!

Question 17

where is reticulocytes found and what is it?

Answer 17

o Found in the bone marrow, it is the final precursor to the formation of RBC
o The last immature form of RBC

Question 18

how long does reticulocytes stay in bone marrow?

Answer 18

o Leaves bone marrow after 3 days, enters bloodstream

Question 19

what happens to reticulocytes after 1 day in circulation?

Answer 19

they lose their ribosomal network and become mature RBC/erythrocytes
* In order to be able to carry O2 throughout the body

Question 20

is retic count a part of a CBC?

Answer 20

no. need to order separate.

Question 21

what is normal retic count?

Answer 21

 Normal (0.5-2%)

Question 22

low retic count

Answer 22

 LOW (<0.5%) -> think UNDERPRODUCTION and there is a component with production of RBC that is missing
** the bone marrow is not producing enough**

Question 23

high retic count

Answer 23

 HIGH (>2%)  think destruction/hemolysis or active bleeding is occurring

Question 24

why is ferritin also called acute phase reactant?

Answer 24

if theres an infection going on–>ferritin will increase, doesnt necessarily mean theres an iron deficiency

Question 25

underproduction anemia: Microcytic

Answer 25

o MCV low (<80) – cells are smaller
o Low retic count – think underproduction

Question 26

what are possible causes of microcytic anemia? (5)

Answer 26

 Iron deficiency
 inflammation (anemia of chronic disease)
 Thalassemia
 Sideroblastic- marrow produces ringed sideroblasts rather than healthy RBC’s secondary to genetic disorder vs myelodysplastic syndrome
 Lead exposure

Question 27

underproduction anemia: macrocytic

Answer 27

o “underproduction anemia”
o MCV high (>100) – cells are bigger
o Low retic count
o High MCH weight

Question 28

what are the two groups of macrocytic anemia?

Answer 28

o Two groups-
 Megaloblastic (abnormal shape of RBC, usually bigger in shape, and typically anemia of impaired DNA synthesis)

 Nonmegaloblastic

Question 29

what conditions will you see Megaloblastic in? (3)

Answer 29

Will see it in-
o B12 deficiency
o Folic acid deficiency
o antimetabolite drugs (methotrexate or zidovudine)

Question 30

what conditions will you see Nonmegaloblastic in? (5)

Answer 30

• Will see it in-
  o ETOH
  o liver disease
  o MDS
  o Hypothyroidism – you check a TSH
  o Meds- anti seizure, chemo drugs

Question 31

what deficiency is macrocytic anemia typically present in?

Answer 31

typically in someone with vitamin B12 deficiency

Question 32

underproduction anemia: normocytic

Answer 32

o “underproduction anemia”
o normal-sized red blood cells, but you have a low number of them
o MCV normal (80-100)
o Low retic count

Question 33

underproduction anemia: normocytic possible causes

Answer 33

 Inflammation
 Malignancy
 RBC aplasia secondary to;
* aplastic anemia
* suppression by parovirus B19
* medications
 Hospitalized patient
* Dilutional from IVF in a small period of time
* Iatrogenic secondary to phlebotomy
 Post hemorrhagic anemia is a normocytic-normochromic anemia (NNA) caused by acute blood loss

Question 34

Anemia of Inflammation- Normocytic (6)

Answer 34

 Elevated ferritin
* d/t iron isn’t an issue
 normal or reduced TIBC
 normal peripheral smear
 NO classical presentation
 Most common anemia in a hospitalized patient!
 Acute or chronic immune activation
* Any disease or infectious state

Question 35

Anemia of Inflammation- Normocytic possible causes

Answer 35

• Cytokine-induced  leads to changes iron homeostasis
  o [Cytokines-interferons, interleukins, tumor necrosis factor]
  o Impaired proliferation and differential of erythroid progenitor cells
  o Blunted erythropoietin response
  o Increased erythrophagocytosis
• CKD/ESRD
  o Lack erythropoietin and have marked inflammation- pts received EPO (these patients will be put on EPO 3x a week b/c their kidney cells arent producing EPO)
• Autoimmune diseases
  o SLE, RA, vasculitis, sarcoidosis, and inflammatory bowel disease.
• Acute/chronic infections
• Cancer—with multiple cytopenia’s
  o [think bone marrow infiltration secondary to leukemia, lymphoma, multiple myeloma, MDS, aplastic anemia]
• Endocrine diseases
• Liver disease
   Treatment- TREAT THE UNDERLYING CHRONIC DISEASE

Question 36

what are Macrocytic (megaloblastic) anemia

Answer 36

o are characterized by abnormally large erythroid precursors (megaloblasts) in the marrow that mature into large erythrocytes (macrocytes)
o cells are challenged to make DNA
 however, RNA production proceeds normally.
o The cells have slow-maturing nuclei but have normal maturing cytoplasm.
o Therefore, megaloblastic erythroid precursors grow large before the larger nuclei become mature enough to signal division
 causing the cell to be larger than normal

Question 37

what are microcytic anemia

Answer 37

Characterized by abnormally small erythrocytes that contain unusually reduced amounts of hemoglobin.
 The most common nutritional disorder of microcytic-hypochromic anemia—iron deficiency anemia
* Most common cause of anemia worldwide ^^
* Top two causes— Blood loss from GI or menstrual
* Other causes— Inadequate intake of meats (rare), Malabsorption with patients who have had gastrectomy, bariatric surgery procedures, celiac disease, IBS
o In smear they look small, fewer, and pallor

Question 38

what is the most common cause of anemia worldwide?

Answer 38

iron deficiency microcytic anemia

Question 39

the definition of anemia

Answer 39

• decreased in circulating RBC in the body, as reflected by a reduction in hgb, hct, and/or RBCs
  o Hgb <14 males, <12 women
  o Low oxygen capacity
   There is not enough hgb available to carry the O2
  o Anemia is NOT a disease; it is a condition.
   YOU TREAT THE DISEASE that is causing the anemia!!!

Question 40

what are the causes of anemia? (3)

Answer 40

 Acute or chronic blood loss
 Underproduction of RBCs by the bone marrow
 Increased destruction of RBCs, “hemolysis”

Question 41

definition for iron deficiency anemia

Answer 41

 Microcytic anemia- underproduction!
 A condition of too little iron in the body
 Iron stores are depleted, and reduce hemoglobin synthesis
 Develops slowly through three overlapping stages;
* stage I – body’s iron stores are depleted. Erythropoiesis proceeds normally, with the hemoglobin content of erythrocytes remaining normal.
* stage II – iron transportation to bone marrow is diminished, resulting in iron-deficient erythropoiesis.
* stage III – begins when the small hemoglobin-deficient cells enter the circulation to replace the normal aged erythrocytes that have been removed from the circulation.
o The manifestations of IDA appear in stage III when there is depletion of iron stores and diminished hemoglobin production.

Question 42

what are the three overlapping stages of iron deficiency anemia?

Answer 42

• stage I – body’s iron stores are depleted. Erythropoiesis proceeds normally, with the hemoglobin content of erythrocytes remaining normal.
• stage II – iron transportation to bone marrow is diminished, resulting in iron-deficient erythropoiesis.
• stage III – begins when the small hemoglobin-deficient cells enter the circulation to replace the normal aged erythrocytes that have been removed from the circulation.
  o The manifestations of IDA appear in stage III when there is depletion of iron stores and diminished hemoglobin production.

Question 43

etiology of iron deficiency anemia

Answer 43

 MOST COMMON CAUSE OF ANEMIA WORLDWIDE
* Top two causes— Blood loss from GI or menstrual
* Other causes— Inadequate intake of meats (rare), Malabsorption with patients who have had gastrectomy, bariatric surgery procedures, celiac disease, IBS
* increased requirement of iron
* medications that cause GI bleeding, eating disorders; PICA

Question 44

iron deficiency risk factors (3)

Answer 44

 Pregnancy with continuous blood loss in labor
 Menorrhagia
 H.pylori infections

Question 45

lab findings: microcytic anemia: iron deficiency

Answer 45

 Early-normal CBC, mild with Hgb 9-12
 Low MCH, new cells are smaller and paler (hypochromic)
 Low ferritin
* best measure of iron stores,
* also an acute phase reactant
o [with iron deficiency ferritin is low, it is also acute phase reactant- meaning when you have acute inflammation, it will INCREASE;  so even though you have elevated ferritin levels, it could still mean you have iron deficiency anemia  ALL ABOUT THE CLINICAL PICTURE]
 Low reticulocyte count
* bone marrow doesn’t have enough iron to make red cells
 High total iron binding capacity
* Not enough iron to bind to, but has a lot of capacity for it
 Low serum iron <30
 Poikilocytosis
* found on blood smear with abnormally shaped erythrocytes
 Transferrin saturation < 16% (serum iron x 100/ TIBC)
 Bone marrow biopsy with absence of iron stores (Gold Standard!!)

Question 46

what is the gold standard at diagnosing anemia?

Answer 46

bone marrow biopsy

Question 47

physical exam: iron deficiency anemia

Answer 47

-Fatigue
-irritable
-pagophagia (ice craving)
-pica
-koilonychia (thinning, flattening and then spooning of nail bed)
-hair loss
-glossitis
-stomatitis
-gastritis
-restless leg syndrome (often first sign)

Question 48

what can too much blood transfusion lead to?

Answer 48

iron overload

Question 49

definition: B12 deficiency

Answer 49

 Anemia or nervous system injury from lower than normal amounts of vitamin B12
 Megaloblastic anemia (macrocytic)

Question 50

pathophysiology for B12 deficiency

Answer 50

 B12 is a substrate required for RBC production
 Dietary B12 is protein bound and released by peptic digestion of stomach (ileum)
 B12 intrinsic factor binds to receptors in ileum where B12 is absorbed
* IF is an important factor in the gut, helps absorb
 B12 important for DNA synthesis with folate
 Decreased B12 can lead to demyelination of finer neurons with lead to neuro symptoms
* Can lead to irreversible damage but can be reversed if caught early enough
* [if your patient presents with neuro ss, think of vB12 deficiency this is because neuro ss can be at time irreversible]
 Takes years to develop because liver has extensive stores of vB12
* B12 levels can be falsely low in folate deficiency, pregnancy, and use of oral contraception
* Levels can be falsely normal in myeloproliferative disorders, liver disease, and bacterial overgrowth syndromes

Question 51

common causes: macrocytic anemia: B12 deficiency

Answer 51

 B12 malabsorption from food:
* When B12 isn’t released from food proteins because of impaired acid peptic digestion
o Atrophic gastritis (chronic H pylori infections), gastric surgery, long term acid suppressing meds
o Meds:
 PPI (diminish breakdown of B12 from food source)
* Always check a vB12, since are at risk!
 metformin/neomycin… (decreases absorption of vB12)
o Malabsorption in terminal ileum secondary to resection, bypass, or Chron’s disease
 Lack of intrinsic factor
* Secondary to gastrectomy
* pernicious anemia – type of megaloblastic anemia and is caused by vB12 deficiency, often associated with chronic atrophic (autoimmune) gastritis
o impairs the production of IF
o pernicious= highly injurious or destructive and reflects the fact that this condition was once fatal
o uncommon before 30, usually after 50
o 25% of patients have a fam hx of pernicious anemia and 10% have autoimmune thyroid disease
 You test for the antibody, if it is + then they have pernicious anemia
 Dietary deficiency
* Rare, unless they are true vegans or malnourished
* Since animal food is the primary natural source of B12, including milk, cheese, eggs, meat.

Question 52

physical exam: B12 deficiency (3)

Answer 52

• Paresthesia/peripheral neuropathies,
• ataxia
• cognitive impairment

Question 53

lab findings for B12 deficiency

Answer 53

 Low reticulocyte count
 Elevated MCV- macrocytic
 Low B12
* less than 200-likely deficient
* 200-300 equivocal
* >300- likely ok (no pernicious anemia)
 Intrinsic factor antibody
* + in pernicious anemia
 Increased methylmalonic acid (MMA)*
* B12 helps convert methylmalonyl CoA to succinyl CoA
o in B12 deficiency methylmalonyl CoA converts to MMA instead
* Without B12, you will have increase in byproduct MMA  which is a big indication for B12 deficiency
 Increased homocysteine
* amino acid formed from the conversion of methionine to cysteine
* not as specific/sensitive as MMA test
* will also be elevated in folate deficiency and hypothyroidism
 May have associated thrombocytopenia and neutropenia
 Smear
* macro-ovalocytes, Howell jolly bodies, nucleated RBCs, hyper segmented neutrophils
 Schilling’s test
* Checks B12 absorption but not common test, rarely used

Question 54

complications/consequences for macrocytic anemia: B12 deficiency

Answer 54

 Neurocognitive disorders
 Encephalopathy
 Myelopathy
 Peripheral and optic neuropathy
 Alzheimer disease
 For Pernicious Anemia  increased risk for gastric carcinoma. Untreated PA is fatal, usually because of HF

Question 55

which anemia is common for alcoholics?

Answer 55

macrocytic anemia–folic deficiency

Question 56

definiton: macrocytic anemia: folate deficiency

Answer 56

 Deficiency in folic acid, results in a megaloblastic anemia (macrocytic)
 Folate is an essential vitamin for RNA and DNA synthesis within the maturing erythrocyte

Question 57

risk factors for folate deficiency anemia

Answer 57

 Alcoholics – not having enough
 Pregnant woman – needing more
 Patients taking Medications that are antagonist to folic acid

Question 58

causes of folate deficiency anemia

Answer 58

 Most common cause of macrocytic anemia
 Inadequate dietary intake
* especially in alcoholic patients
 body stores only 4-5 months
 absorption occurs in jejunum
* malabsorption is rare except in short bowel syndrome or bacterial overgrowth syndrome
 increased demand in pregnancy, chronic hemolysis, leukemia
 meds (methotrexate, phenytoin, sulfasalazine)
 alcohol
* folate gets depleted with alcohol

Question 59

physical exam: folate deficiency (8)

Answer 59

• diarrhea
• HA
• loss of appetite
• weight loss
• fatigue
• SOB
• dizziness
• pallor

Question 60

lab findings: folate deficiency anemia (5)

Answer 60

 Low retic count (because the ingredient to make folic acid isnt there to make reticulocytes)
 elevated MCV and MCH
 thrombocytopenia and neutropenia +
 elevated homocysteine
* this one is MORE sensitive for folate deficiency
 low RBC folate

Question 61

Microcytic (iron deficiency)

Answer 61

 Most common cause of anemia worldwide and usually from GI bleed or menses
 Low ferritin and high TIBC

Question 62

Normocytic anemia (of chronic disease)

Answer 62

 Most common anemia of hospitalized pt
 Cause of acute or chronic inflammation
 Elevated ferritin, normal or reduced TIBC, normal smear

Question 63

Macrocytic anemia (B12 and folic acid deficiency)-what are the caused by and what are the additional testings?

Answer 63

 B12 deficiency is usually from poor absorption and will have neurological symptoms
 Folic acid deficiency is usually caused by poor intake or pregnancy
 Additional testing: IF antibody (pernicious anemia), MMA, and homocysteine

Question 64

definition: sickle cell anemia

Answer 64

 Disorder that causes RBC to become misshapen or break down
 Identified at birth
* 6 months when HbS replaces fetal Hg
 Confirmed by hgb electrophoresis*, CBC, retic count, and smear
* used to detect abnormal and variant Hgb like HbS

Question 65

pathophysiology of sickle cell anemia

Answer 65

 Caused by autosomal recessive single gene defect in beta chain of HbA, which results in sickle cell HbS
 Crescent shaped/sickle cell Hgb can obstruct small blood capillaries causing painful crises, damage major organs and increase vulnerability to infections
* Replacement of both beta Hgb subunits with HbS is diagnostic for sickle cell anemia (genotype SS)
o Most severe
o Need both genes in order for it to be sickle cell
* Presence of 1 normal beta hgb subunit and 1 HbA is sickle cell trait (genotype AS)
o Child inherits HBS from one parent and normal HbA from the other
o Carrier state, not the actual disorder

Question 66

lab studies: sickle cell anemia

Answer 66

 Presence of nucleated RBC’s sickle shaped cells, and Howell-jolly bodies on smear
* Nucleated RBC will also falsely elevate WBC count if not corrected because sickled cells are read as WBCs
 Normal iron studies
 Elevated retic count
 high MCV
 elevated unconjugated bili
 elevated LDH
 low haptoglobin

Question 67

types of crisis: sickle cell anemia (4)

Answer 67

 Vaso-occlusive crises (pain)
 Aplastic crisis
 Sequestration crisis
 Hyperhemolytic crisis
* Association with certain drugs/infections

Question 68

concerns/complications: sickle cell anemia

Answer 68

 Aplastic crisis is associated with fever, more profound anemia, and hemolysis and parovirus B19 is often the cause
 Avascular necrosis of joints
 Retinopathy, cholelithiasis, splenic sequestration and auto-splenectomy, liver disease from iron overload
* iron is being spat back into blood with the sickling
 Acute chest syndrome (ARDS), pulm HTN, reactive airways
 Type 4 renal tubular acidosis, proteinuria
 Priapism
 Ischemic/hemorrhagic stroke
 INFECTION, a significant cause of mobidity/mortality

Question 69

definition: hemolytic/hereditary: thalassemia

Answer 69

 blood disorder involving less than normal amounts of an oxygen-carrying protein
 diagnosed at a young age
 inherited autosomal recessive disorder that causes an impaired synthesis of one of the two chains, alpha/beta

Question 70

pathophysiology: thalassemia

Answer 70

 Red cells are microcytic due to defective production of either alpha or beta globin chain
 Resulting imbalance in globin subunit production leads to damage of the RBC membrane, resulting in ineffective erythropoiesis and hemolysis

Question 71

pathophysiology for Alpha-thalassemia

Answer 71

 Patho:
* Most common
* Common in Asian (68%), African (30%), and Mediterranean (5-10%)
* 4 genes will determine synthesis of alpha chain
o any variation of 4  alpha
* ¼ abnormal: silent carrier-
o usually asymptomatic, clinically normal
* 2/4: alpha thalassemia minor (trait)-
o mild microcytic anemia
* ¾: alpha thalassemia intermedia (HbH disease)-
o chronic anemia, pallor, hepatosplenomegaly, frontal and maxilla body overgrowth, pathologic fractures, pigmented gallstones (full of unconjugated bili), iron overload
* 4/4: alpha thalassemia major hydrops fetalis-
o associated with stillbirth or death shortly after birth
o causes congestive HF intrauterine

** A thalassemia is an inherited blood disorder. It causes the body to make less hemoglobin than normal. There are 4 different types of alpha thalassemia. This condition causes mild to severe anemia, based on the type of alpha thalassemia that is inherited.

an inherited blood disorder in which the body doesn’t make as much alpha globin

Question 72

lab findings: Alpha-thalassemia

Answer 72

• Smear with hypochromia, microcytic, target cells, red cell fragments, basophilic stippling
• Normal or increased RBC count
• Normal or increased iron and iron stores
• Hgb can be as low as 3-6

Question 73

patho:o Beta- thalassemia

Answer 73

• Genetic syndrome of ineffective erythropoiesis caused by mutations of the beta-globin gene and no production of the beta chain, which leads to absent HgbA
  o This leads to excess alpha-chains
• Found in Mediterranean, African, Indian, and Asian ancestry

Question 74

Beta thalassemia minor (trait)

Answer 74

o only one gene defective leading to about 50% decrease in beta-chain synthesis
o usually asymptomatic, mild microcytic anemia

Question 75

Beta thalassemia Intermedia

Answer 75

o about 90% HgbA with increased HgbA2 (alpha, delta, and gamma chains) and Hgb F
 similar presentation as major but as a toddler or child with milder symptoms
o Associated with anemia, hepatosplenomegaly and body disease

two of the genes are affected

Question 76

• Beta thalassemia Major (Cooly’s anemia)-

Answer 76

o usually asymptomatic at birth, due to presence of fetal HbF but symptomatic at 6 months with decline of HgbF
o Deficient beta chains leads to excess alpha chains not able to form tetramers, leads to ineffective erythropoiesis, erythroid hyperplasia and extramedullary hematopoiesis
 frontal bossing and maxillary overgrowth
o Hepatosplenomegaly, severe hemolytic anemia (jaundice, dyspnea, pallor), osteopenia and stunted growth, iron overload, pigmented gallstones

Question 77

lab findings: beta thalassemia

Answer 77

• Low Hgb/HCT
• low MCV
• normal/elevated retic count
• increased RBC
• Smear will show;
  o microcytic red cells, tear drops, microspherocytes, target cells, many nucleated red cells
• Major will show;
  o minimal to no HbA,
  o elevated HbF and HbA2
• Normal iron studies

Question 78

DESTRUCTION/HEMOLYTIC TYPE OF ANEMIAS

Answer 78

o No classic presentation
o anemia with elevated retic count
o Two types of Hemolytic Anemia intrinsic and extrinsic

Question 79

destruction/hemolytic anemia: intrinsic/heredity etiology

Answer 79

• Enzyme defects such as pyruvate kinase or glucose-6 phosphate dehydrogenase (G6PD) deficiency
• Hemoglobinopathies like sickle cell anemia and Thalassemia
• RBC membrane abnormalities, such as spherocytosis

Question 80

destruction/hemolytic anemia: extrinsic/etiology

Answer 80

an acute process or medication causing this
* Autoimmune hemolytic anemia
* Disseminated Intravascular Coagulation (DIC)
o Concomitant thrombocytopenia and coagulopathy
 prolonged PT, decreased fibrinogen, elevated D-dimer, decreased factors V, VIII, X, XIII
o Can find purpura and/or petechiae from thrombocytopenia
* Thrombotic Thrombocytopenic Purpura (TTP)
o Concomitant thrombocytopenia, renal insufficiency, neurological symptoms
* Hemolytic Uremic Syndrome (HUS)
o Concomitant thrombocytopenia, renal insufficiency, neurological symptoms
* Paroxysmal nocturnal hemoglobinuria
* Hypersplensim
* Traumatic (something is injuring the RBC)
o Impact
o Macrovascular shearing secondary to prosthetic valve (literally cutting those RBCs–>the cells are lysing and being shattered which is causing the anemia)
o Microvascular (the irritation to the lining of the vessels-from medication, acute process, or a new cancer dx) (DIC, TTP, HUS)
* Toxins- snake venom and aniline dyes

Question 81

patho: DESTRUCTION/HEMOLYTIC TYPE OF ANEMIAS

Answer 81

 During hemolysis, RBC products are released into the circulation and their presence can be measures to support the dx of hemolysis

Question 82

lab findings: DESTRUCTION/HEMOLYTIC TYPE OF ANEMIAS (6)

Answer 82

 Elevated Lactate dehydrogenase (LDH):
* enzyme found in RBCs (also the muscle, brain, liver, and kidneys
* Released with cell damage., it is a byproduct released from lysis of RBC
* Also elevated in liver disease and other disease process (pancreatitis, CHF, malignancy, skeletal muscle disease, medications )
 Elevated reticulocyte count: RBC are being destroyed in the circulation, the body will compensate and the bone marrow will try to generate more RBC and the reticulocyte is the immature RBC)
 Low Haptoglobin
* acute phase reactant protein made by the liver.
* Primary function is to preserve iron by irreversibly binding free hemoglobin from lysed RBCs.
o With increased LDH, 90% specific for hemolysis— haptoglobin production is exhausted from responding to the lysed RBCs
 Elevated Indirect Bilirubin
* measure of unconjugated bilirubin.
* Heme breakdown into unconjugated/indirect bilirubin.
o In liver, unconjugated/indirect bilirubin conjugates to glucuronic acid to form conjugated/direct bilirubin and excreted via biliary system to small intestines and out with feces.
* Overwhelmed liver unable to conjugate and can lead to jaundice.
 Positive Direct Coombs/Direct Antiglobulin Test (DAT)
* detects IgG/IgM antibody on the surface of the RBC, found in autoimmune hemolytic anemia
o aid in the processing and removal of immune complexes
 Positive schistocytes on peripheral smear
* Fragmented RBCs found in traumatic hemolysis
* Destruction can occur in the spleen, liver or small blood vessels
o i.e. small vessel thrombosis in DIC, TTP, HUS

Question 83

define Hematopoiesis

Answer 83

the production of blood cells

Question 84

define erythropoiesis and where does it occur

Answer 84

the production of erythrocytes (RBC)

 occurs mostly in the bone marrow in flat bones of pelvis, vertebrae, cranium/mandible, sternum, ribs, and proximal portions of the humerus and femur.

Question 85

what are the requirements for RBC production

Answer 85

Amino Acids, copper, cobalt, Vitamin B (2,3,6,12), folate, Iron, and Vitamin E
 When there isn’t enough of any one of these, we start running into problems with anemia

Question 86

pathophysiology: RBC production

Answer 86

 Production of RBC is stimulated by the hormone erythropoietin
* hormone secreted by the kidneys, when decreased oxygen is detected either from;
o decreased oxygen content in the blood
o decreased blood flow
o decreased hemoglobin
 i.e. sepsis, dehydration, acute blood loss
 When EPO stimulates the production of erythrocytes  iron is released from storage (mostly from bone marrow, liver, and spleen),  binds to transferrin,  carried to the red marrow where it attaches to erythrocyte precursors

Question 87

Relate hemoglobin and hematocrit values

Answer 87

• Hemoglobin: g/dL whole blood, measurement of mass Hgb
  o Normal range= >13 in men >12 in women
• Hematocrit: % whole blood with intact RBCs, physical amount of space that the hgb occupies as a percentage of the whole that red cells occupy
  o Normal range: 40-50 in men, 35-45 in women
  o Usually 3x the hgb count

Question 88

describe thrombocytopenia

Answer 88

Thrombocytopenia: a condition in which there is a lower than normal number of platelets in the blood
o Normal platelet count : 150,000-450,000

Question 89

clinical manifestations of thrombocytopenia

Answer 89

o Easy or excessive bleeding (purpura)
o Superficial bleeding into the skin that appears as a rash of pinpoint sized reddish-purple spots (petechiae), usually on the lower legs
o Prolonged bleeding from cuts
o Blood in urine or stools
o Bleeding from your gums or nose
o Unusually heavy menstrual flows
o Fatigue
o Enlarged spleen

Question 90

define Poikilocytosis and for which anemia is it found in

Answer 90

a term that refers to the presence of abnormally shaped red blood cells
o It is found on blood smear with abnormally shaped erythrocytes for microcytic anemia-iron deficiency

Question 91

define Schistocytes

Answer 91

are red blood cell fragments; the presence of this suggest red blood cell injury from the endothelium
o In destruction/hemolytic anemias- positive schistocytes are found on a peripheral smear
o Fragmented RBCs found in traumatic hemolysis
o Used in diagnosis of DIC, TTP, HUS