Episode 8 Overview of Hematological Pathology

Question 1

What is anemia?

Answer 1

A reduction one or more of the major RBC measurements - Hg concentration, hematocrit, and/or RBC count

Question 2

What is the most common cause of anemia worldwide?

Answer 2

Iron deficiency

Question 3

What is the result of defective Hb synthesis on RBC formation?

Answer 3

Microcytic (MCV is low) and Hypochromic (low MCH and MCHC)

Question 4

Why do pencil cells appear in a blood smear?

Answer 4

Unbalanced surface membrane to cytoplasmic volume due to reduced Hb

Question 5

What does a reduced rate of Hb synthesis result in?

Answer 5

More cell division and smaller cells

Question 6

How do lower levels of Hb affect the appearance of RBCs?

Answer 6

They look pale

Question 7

What are the major causes of iron deficiency?

Answer 7

Blood loss, decreased iron absorption (GI tract problem or drug induced), Dietary, Increased iron requirements (pregnancy and growth spurts)

Question 8

What is the effect of vitamin B12 deficiency on RBCs?

Answer 8

RBCs become macrocytic (MCV is elevated)

Question 9

What are enlarged RBCs sometimes referred to as?

Answer 9

Megaloblasts - “megalobalstic anemia”

Question 10

Which is affected by vitamin B12 - RNA or DNA?

Answer 10

DNA, RNA is unaffected and protein synthesis continues and accumulates making the RBC larger

Question 11

What are the main causes of Vitamin B12 deficient anemia?

Answer 11

Lack of intrinsic factor (IF), dietary, and gastrectomy or other stomach procedures

Question 12

What does the lack of IF lead to?

Answer 12

Decreased absorption of vitamin B12

Question 13

What is pernicious anemia?

Answer 13

Vitamin B12 deficiency specifically due to decreased IF

Question 14

What are the causes in a lack of IF?

Answer 14

Lack of gene, autoimmune attack on IF or on the Parietal cells in the stomach

Question 15

What does an attack on parietal cells produce, besides lack of IF?

Answer 15

Chronic atrophic gastritis

Question 16

T/F Vitamin B12 deficiency and folate deficiency both produce very similar RBCs under the microscope

Answer 16

True, both produce increased MCV

Question 17

Does folate absorption require IF?

Answer 17

No, only Vit. B12 does

Question 18

What are the potential causes of folate deficiency?

Answer 18

Poor nutrition, increased requirements (pregnancy), malabsorption (inflammatory diseases of the intestines), Drugs interfering with absorption

Question 19

What are the general features of anemia due to acute blood loss?

Answer 19

Increased HR and Low BP

Question 20

Why would Hb concentration and a full blood count taken immediately after acute blood loss be normal?

Answer 20

B/c RBCs and plasma are lost together

Question 21

When MCV remains normal during this is called what?

Answer 21

Normocytic

Question 22

Where must the movement of fluid go to develop anemia after acute blood loss?

Answer 22

From the extravascular space to the intravascular

Question 23

What is anemia due to chronic blood loss most often associated with in the developed world?

Answer 23

Iron deficient anemia

Question 24

What are examples of anemia due to chronic blood loss?

Answer 24

Unrecognized loss from a bleed gastric ulcer or heavy menstrual flow

Question 25

What is typical of anemia of chronic disease?

Answer 25

It is typically normocytic

Question 26

Why would chronic renal failure cause anemia?

Answer 26

Kidney's produce erythropoeitin, w/o which RBCs production cannot respond to falling oxygen levels in tissues

Question 27

What is a hemolytic anemia?

Answer 27

Disorder in which the RBCs are destroyed faster than normal - bone marrow cannot keep pace with the rate of destruction

Question 28

How few days may RBCs live when someone has hemolytic anemia?

Answer 28

As few as 20 days

Question 29

What is the autoimmune response directed against in Acquired Autoimmune Hemolytic Anemia?

Answer 29

RBCs own antigens

Question 30

Virtually all hereditary anemias are what?

Answer 30

Hemolytic

Question 31

Inherited anemias may be classified into what three major groups of disorders?

Answer 31

Those affecting: 1) RBC membrane - spherocytosis, elliptocytosis 2) RBC enzymes - G6PD deficiency 3) Hb molecules - sickle cell, thalassemia

Question 32

What defects cause hereditary spherocytosis?

Answer 32

Molecular defects in genes that code for Ankryn, Protein 4.2, Spectrin, Band 3 protein

Question 33

What is the most helpful RBC index in hereditary spherocytosis?

Answer 33

Mean Cell Hemoglobin Concentration (MCHC), which is routinely elevated

Question 34

What does an elevated MCHC indicate?

Answer 34

membrane loss and RBC dehydration

Question 35

What does an elevated RDW favor the diagnosis of?

Answer 35

hereditary spherocytosis

Question 36

What is the difference between Hereditary Elliptocytosis (HE) and pencil cells in iron deficient anemia?

Answer 36

Pencil cells in iron deficient anemia appear occasionally by with HE the vast majority of cells look elliptical

Question 37

When would an Osmotic Fragility Test (OFT) be performed?

Answer 37

When one is suspected of having spherocytosis or elliptocytosis

Question 38

What is the OFT?

Answer 38

Measure of RBC lysis in an NaCl concentration at which 50% lysis occurs - spherocytes and elliptocytes lyse more readily than normal RBCs

Question 39

G6PD is the only source of what in RBCs?

Answer 39

NADPH, which maintains glutathione in its reduced form

Question 40

The RBCs of G6PD often show what characteristics?

Answer 40

Heinz Bodies (a cluster of denatured Hb) and Bite cells (removal of HBs afterr processing thru the spleen)

Question 41

Where are HBs usually located on an RBC?

Answer 41

Periphery - look like olives with pits

Question 42

What is the sickle cell anemia a result of?

Answer 42

Point mutation in the Beta globin gene - resulting in the change of amino acid number 6 - Glutamate to Valine

Question 43

What is Thalassemia?

Answer 43

Unbalanced globin chain production

Question 44

Where is thalassemia prevalent?

Answer 44

Some of the same areas as sickle cell anemia - Africa, Mediterranean, Middle East, India, and Asia

Question 45

How is thalassemia classified?

Answer 45

Classified after the gene affected - alpha-thalassemia if the alpha-globin gene is altered, or beta-thalassemia etc

Question 46

What is the consequence of thalassemia?

Answer 46

RBCs that are microcytic and hypochromic

Question 47

What cells get cancer in Leukemia?

Answer 47

WBC precursors

Question 48

What are the two classic leukemia forms?

Answer 48

Acute and chronic

Question 49

What happens in leukemia?

Answer 49

progressive accumulation of abnormal WBCs in the bone marrow and other organs, which spill out into the peripheral blood; progressive bone marrow failure with a reduction in other normal cell types. Tend to have reduced number of RBCs and Megakaryocytes

Question 50

What is Acute Myeloid Leukemia (AML)?

Answer 50

Cancer of myeloid line of stem cells. Rapid growth of abnormal WBCs that accumulate in bone marrow an interfere with production of normal blood cells

Question 51

What is the most common acute leukemia?

Answer 51

AML

Question 52

What are the symptoms of AML?

Answer 52

Tiredness, infections, bruising, bone pain, respiratory and neurological symptoms

Question 53

What are the symptoms of AML caused by?

Answer 53

drop in RBCs, platelets, and normal WBCs

Question 54

What is acute lymphoblastic leukemia (ALL)?

Answer 54

cancer of lymphoid line of stem cells

Question 55

At what age is ALL most common? AML?

Answer 55

ALL is most common in ages 2-5. AML is most common in adults and increases with age

Question 56

What is the difference b/w acute (AML) and chronic (CML) myeloid leukemia?

Answer 56

CML has the presence of the Philadelphia chromosome

Question 57

What is the Philadelphia chromosome?

Answer 57

Translocation in which two parts of two chromosomes 9 and 22 are swapped

Question 58

What does the Philadelphia chromosome mutation lead to?

Answer 58

Transcription of proteins with high tyrosine kinase activity

Question 59

What does the drug Gleevec treat?

Answer 59

CML

Question 60

What are three phases of CML?

Answer 60

Chronic phase, Accelerated phase, and Blast Crisis

Question 61

Where is the Chronic Lymphoblastic Leukemia most common?

Answer 61

Western societies w/ a peak incidence in pts b/w 60-80 and a male:female ratio of 2:1

Question 62

CLL is a slow-growing disorder characterized by progressive accumulation of cancerous cells where?

Answer 62

Bone marrow, spleen, liver, and lymph nodes

Question 63

What is the difference between leukemia and lymphoma?

Answer 63

Leukemia is a cancer of WBC precursors that occurs in the bone marrow. Lymphoma is a solid mass tumor that can originate w/in many different lymphoid tissues - lymph nodes (most common), spleen, liver, GI tract, thymus or bone marrow

Question 64

What are the symptoms of Hodgkin's lymphoma?

Answer 64

Itchy skin, night sweats, unexplained weight loss, enlarged lymph nodes, splenomegaly, hepatomegaly

Question 65

What type of cells are characteristically seen in biopsies of Hodgkin's lymphoma?

Answer 65

Reed-Sternberg cells - AKA "popcorn cells"

Question 66

What are Reed-Sternberg cells - AKA "popcorn cells"?

Answer 66

B lymphocytes that have lost the ability to produce antibodies

Question 67

What is the prognosis for Hodgkin's Lymphoma?

Answer 67

Good prognosis (unlike Non-Hodgkin's Lymphoma)

Question 68

What is Non-Hodgkin's Lymphoma (NHL)?

Answer 68

A group of lymphoma's that includes everything Hodgkin's Lymphoma. No good prognosis for treatment or cure