PHAR 232: Hematology-RBC

What are the 16 lab test for hematology?

1. Hematocrit

2. hemoglobin

3. rbc count

4. mcv

5. ferritin

6. iron

7. iron saturation

8. MCH

9. MCHC

10. reticulocyte count

11. TIBC

12. Transferrin Saturation

13. Transferrin

14. Folic acid

15. vitamin B12

16. blood smear

The assessment of anemia:

1. The amount of ___ and the amount ____.

2. The overall dimensions and health of the____.

1. The amount of iron in the blood and the amount stored in the tissues

2. The overall dimensions and health of the Red Blood Cells

What is the iron cycle?

Iron is:

1. absorbed

2. recycled

3. excreted (or lost)

4. Stored

Iron is absorbed by the …

GI tract

What effects iron absorption?

poor diet and malabsorption

Iron is recycled from…

dead blood cells

What are two ways iron is lost?

1. bleeding due to wounds

2. ulcer

What can happen if any step of the iron cycle goes wrong?

anemia can develop

excessive iron accumulation can occur

iron by itself is __ in the body

toxic = number one cause of poisoning in children

iron is in the ___ and it is stored in the ___

blood, body

How much of iron are distributed in the body?

1. approx 50% in the body is in hemoglobin

   1. other 50 is found in tissues and stored as iron

Can you evaluate iron only in the blood or body?

both can be evaluated

How many atoms can ferritin-storage iron store?

can store up to 4500 atoms of iron per molecule

ferritin = ___ + ____

iron, apoferritin

what is serum ferritin?

a small amount of ferritin is found in the blood

What is the best indicator of iron deficiency anemia (IDA)?

serum ferritin

ferritin lab result = ___

serum ferritin

Does normal and high iron levels needs careful evaluation?

yes

What is ferritin?

an acute phase reactant

what is ferritin associated with?

inflammation

Iron levels can be falsely high in…

RA, infection, etc

What is transferrin (TRF)?

a protein that carries serum iron in the serum

What is TIBC and what does it measure?

Total Iron Binding Capacity

→measures the binding ability of transferrin

what is the normal range for TIBC?

250-460 mcg/dL

Will TIBC be high or low in iron deficiency?

high

What is transferrin saturation %?

serum / TIBC

Will transferrin saturation % high or low in iron deficiency?

low

What is the normal range for transferrin saturation %?

30-50%

describe behavior of serum iron and transferrin in normal iron levels.

iron is bound to transferrin-high saturation and low binding capacity

describe behavior of serum iron and transferrin in abnormal or deficient iron levels.

More transferrin is produced when Iron is low.

Low transferrin saturation

what are the 4 main indices for RBC?

Hgb

Hct

RBC count

MCV

What are the secondary indices for RBC?

MCH, MCHC, RDW, reticulocyte count

Helper labs: B12, Folate (folic acid)

Peripheral Blood Smear (PBS)

what is Hgb?

Hgb-Hemoglobin concentration is the

concentration of hemoglobin in g/dL

What is Hct?

Hct-Hematocrit, also called packed cell

volume, is the packed spun volume of blood

that consists of intact RBCs, expressed as a

percentage

equation for Hct

(Hct= MCV x RBC)

what is RBC?

RBC-RBC count is the number of RBCs

contained in a specified volume of whole

blood (# x 106/μl)

What is MCV?

Mean corpuscular volume (MCV) =

The average volume (size) of the

patient's RBCs.

→It can be measured or calculated

(MCV in femtoliters [fL] = 10 x HCT [in

percent] ÷ RBC [in millions/microL]).

High MCV

macrocytic

High MCV (macrocytic) usually caused by

1. Folate or B12 deficiency: Most common macrocytic anemia

2. Drug toxicity: Zidovudine, hydroxyurea

3. Abnormal RBC maturation: seen in some leukemias

4. Alcohol abuse, hypothyroidism, liver disease

low MCV

microcytic

low MCV (microcytic) usually caused by

1. Iron deficiency

2. Disorders of heme synthesis

3. Chronic inflammatory states

What is RDW?

Red cell distribution width

→Coefficient of variation of the MCV

→RDW = Standard deviation of RBC size ÷ MCV x 100

what is Anisocytosis?

An increased RDW indicates the presence of increased variability in red cell size

is RDW useful by iteslf?

no

what is used with RDW for interpretation?

Use with peripheral blood smear for interpretation

What is MCH?

Mean Corpuscular Hemoglobin

→Amount of Hgb per RBC cell count

→(Hgb/RBC count) x10 = MCH

Low MCH is seen in

IDA and thalassemia

High MCH is seen in

macrocytosis

What is MCHC?

Mean Corpuscular Hemoglobin Concentration

→Concentration of Hgb per dL of RBC

→Hgb/(MCV x RBC) = MCHC

Low MCHC is seen in

IDA and thalassemia

High MCHC is seen in

rarer diseases, unusual

About how much of RBCs are destroyed daily and replaced with new RBCs?

1%

life span of a RBC

120 days

Normal ranges for RBC

0.5 - 1.5% of total RBC count

What does reticulocyte count indicate?

indicates the ability of bone marrow to produce new RBC

→can show loss of mature RBC

large increase of RBC are seen in

hemolytic anemia or acute blood loss

→if bone marrow is functioning

decrease in reticulocytes indicates

ineffective hematopoiesis despite the anemia

→bone marrow is not functioning

when does reticulocytosis not happen?

will not happen if there is not adequate iron to support erythropoiesis

What are the four anemia focuses?

1. Macrocytic Anemia

2. Hemolytic anemia

3. iron deficiency anemia (IDA)

4. Anemia of chronic disease (or inflammation)

What is anemia?

When RBC creation is less than RBC destruction

What are 5 causes of anemia?

1. Lack of nutrients (Iron, B12, Folate, etc)

2. Bone marrow disorders (Cancers, radiation exposure, etc.)

3. Low levels of trophic hormones (EPO)

4. Chronic inflammation (Chronic disease)

5. Blood loss (Acute and chronic)

All anemias have what in common?

HCT/Hgb/RBC are low

how are anemias differentiated?

The type of anemia is then differentiated by the RBC indices

Physical presentation of anemia includes:

 Pallor

 Fatigue

 Tachycardia

 Orthostatic hypotension

 Koilonychia- spoon nail

 Stomach pain

 Black, tarry stools

→(+)melena

physical presentation of anemia is linked to what?

Physical presentation linked to decreased oxygen delivery to tissues and with acute bleeding, hypovolemia.

hemoglobin, hct, and rbc count are all

concentrations

hemoglobin, hct, and rbc count are all dependent on the

red blood cell mass (RCM) as well as plasma volume

Values for all three parameters (hemoglobin, hct, and rbc count) will be ______ if the RCM is _____ and/or if the plasma volume is _____.

Values for all three parameters will be reduced if the

RCM is decreased and/or if the plasma volume is

increased

Values for all three (hemoglobin, hct, and rbc count) will be ____ if the plasma volume is _______ (ie concentration).

values for all three will be increased if the plasma volume is decreased (ie, hemoconcentration).

what is the first and second step in assessing anemia?

low H&H (hemoglobin and hematocrit) or RBC count, the next step is to evaluate MCV

next step after determining low MCV in anemia

1.evaluate iron stores

2.evaluate possible blood loss

what type of anemia occurs if MCV is low or normal

IDA and Anemia of chronic disease (inflammation)

next step after determining normal MCV in anemia and what type of anemia is this

evaluate reticulocyte count

hemolytic anemia

next step after determining high MCV in anemia

evaluate folate and B12

what type of anemia occurs if MCV is high

macrocytic anemia

Deficiency in what is a common cause of Macrocytic anemia?

B12 and folate

Is macrocytic anemia drug induced and what are some examples?

yes

 Bactrim (SMX-TMP)

 Methotrexate

 Triamterene

 Phenytoin

 Zidovudine (AZT)

 Metformin. (B12 absorption inhibition)

Which type of anemia is the most common?

IDA

is IDA microcytic or macrocytic?

MICROCYTIC----But can be normocytic!

 Depends on the extent of the deficiency

what is a common cause of IDA?

chronic GI bleed

How to evaluate chronic GI bleed in IDA in patients?

 Evaluate patient for meds that can cause GI

bleed.

 Stool Guaiac test (AKA occult blood)

What chronic diseases are ACD or ACI associated with?

 COPD

 Diabetes

 Renal failure

difference between IDA and ACD/ACI

What is the MCV value in hemolytic anemia?

Usually has a MCV that is normal-Normocytic

life span of RBC in hemolytic anemia

Usually an increased destruction of RBCs leading to an

average life span of less than 100 days per RBC

what are some examples of hemolytic anemia?

Examples are: Sickle cell disease, autoimmune

hemolytic anemias, hypersplenism

are reticulocyte levels higher or lower in hemolytic anemia?

Higher levels of reticulocytes can be seen with

hemolytic anemia

what helpful in diagnosing hemolytic anemia?

Blood smear is very helpful in the diagnosis due to sub-

populations of broken or misshapen cells

What else is indirectly elevated in hemolytic anemia?

Indirect bilirubin and Lactose Dehydrogenase can be

elevated