Hematology II Bone Marrow and Anemia

How many times of bone marrow are there

Two-Red and Yellow

What is the yellow marrow primarily composed of and is it active

Fat, and it is inactive

What is the function of red marrow

It is active in hematopoiesis (blood cell production)

How many total marrow space does an adult have

About 4 liters

How much of an adult’s marrow is acitve

About half

How much total marrow space does a child have

About 1.6 liters

How much of a child’s marrow is active

Nearly 100%

Which bone has the highest percentage of total marrow

The pelvis 40%

What are the preferred sites for bone marrow sampling

1. Posterior superior iliac crest

2. Anterior iliac crest in adults

3. Sternum at second intercostal space

What is bone marrow composed of

A jelly like material dispersed among bony trabeculae and supported by a fine reticulin network

How is the bone marrow supplied with blood

By a main nutrient artery with small terminal arterioles

What is special about about the central blood vessel or the central sinusoid in bone marrow

It has a permeable basement membrane similar to the glomerular filtration barrier in the kidney

What does the bone marrow provide for stem cells

A suitable micro-environment for growth and development

What type of stromal cells are found in bone marrow

1. Macrophages or Histocytes

2. Fibroblast or Reticulin cells

3. Fat cells

4. Endothelial cells

5. Osteoblasts

6. Osteoclasts

What does the bone marrow provide for developing cells

A wet, sticky surface for adherence, a normal population of red marrow cells for interaction, and supportive substances like cytokines, growth factors, and extracellular matrix molecules

What is the normal composition of adult bone marrow

50% hematopoietic tissue and 50% fat

What are the 3 developmental periods in hematopoiesis

1. Mesoblastic

2. Hepatic

3. Myeloid

What happens during the mesoblastic period

Blood islands of the yolk sac form, primarily producing RBC’s, and embryonic hemoglobin is produced

What happens during the Hepatic period

At 5-6 weeks, cell production occurs in the liver, fetal HGB is produced, and the spleen, thymus, and lymph nodes also contribute to production

What happens during the Myeloid phase

At the 5th month, the bone marrow becomes the main site of production, and the liver and spleen engage in extramedullary hematopoiesis

What are the indications for bone marrow examination

1. Evaluation of Pancytopenia

2. Leucoerythroblastic anemia

3. Diagnosis and staging of tumors

4. Suspected cases of myelofibrosis

5. Evaluation of myeloproliferative syndrome

6. Dry tap

What is leukoerythroblastic anemia?

A condition where the bone marrow is infiltrated with metastatic anemia, lymphoma, or granuloma

How is the marrow sample typically collected?

By needle biopsy of the iliac crest under local anesthesia.

What is the first step in collecting a marrow sample?

A needle core biopsy is first obtained.

What happens after the core biopsy?

Some jelly-like marrow substance is aspirated and smeared onto a glass slide.

What is the size of the modified Illinois sternal iliac bone marrow aspiration needle for adults?

Size 15

What is the size of the modified Illinois sternal iliac bone marrow aspiration needle for children?

Size 18

What is the size of the Jamshidi bone marrow biopsy needle for adults?

Size 11 or Size 13

What does a trephine biopsy obtain

A solid core of bone and marrow tissue

What type of needle is used for a trephine biopsy?

A specialized needle with a curved edge

Why is a biopsy more accurate than aspiration?

It is better for determining cellularity and detecting bone-involving processes.

What is obtained during bone marrow aspiration?

A jelly-like marrow substance.

How is the aspirated marrow sample prepared?

It is smeared onto a glass slide for examination

What is a bone marrow aspiration used for

A differential

What stain is commonly used for bone marrow aspiration smears?

Wright-Giemsa stain, along with iron and other necessary stains.

What is the normal % of myeloid cells in the bone marrow

60-70%

What % of erythroid cells is considered normal in the bone marrow

20%

What is the normal % of lymphocytes in the bone marrow

15%

What is the normal % of plasma cells in the bone marrow

2%

What is the normal % of Megas, Monos, Fibroblasts, Osteoclasts, and Osteoblasts in the bone marrow

1%

What is the normal M:E ratio

2.5-4.1

What is the M:E ration typically seen in infection

5-6.1

What M:E ratio is associated with anemia

2:1

What is erythroid hyperplasia

An abnormal increase in the number of red blood cell precursors (erythroid cells) in the bone marrow

What does hypercellular bone marrow mean?

An increase in one or more of the cell lines.

What is the usual mechanism behind hypercellularity?

It is usually a compensatory response.

What causes granulocytic hyperplasia?

Infection.

What causes erythroid hyperplasia?

Anemia

What causes megakaryocytic hyperplasia?

Hemorrhage

Hypercellular

What does hypocellular bone marrow mean?

A decrease or complete loss of cellularity.

What is aplasia or hypoplasia?

A significant reduction or absence of bone marrow cells.

What are possible causes of hypocellularity?

Idiopathic factors, chemotherapy, radiation, drugs, and viral infections.

Hypocellular

What anemias are associated with an RPI of < 2 which is ineffective

Hypo proliferative or Maturation

What anemias are associated with an RPI of > 3 which is effective

Hemolytic or Blood loss

What is the goal of a bone marrow transplant?

To rebuild the recipient's blood cells and immune system and hopefully cure the underlying disease.

Where are the donor stem cells obtained from?

Bone marrow or peripheral blood from a healthy donor.

Why are donor cells transferred to the recipient?

Because the recipient's body cannot produce normal blood cells.

What is an autologous transplant?

A transplant using the patient’s own stem cells.

What is an allogeneic transplant?

A transplant using stem cells from a donor of the same species

What is important for allogeneic transplants?

HLA testing or matching.

What is the reference range for RBC for males

4.20-6.00

What is the reference range for RBC for females

3.80-5.20

What is the reference range for HGB for males

13.5-18

What is the reference range for HGB for females

12-15

What is the reference range for HCT for males

40-54

What is the reference range for HCT for females

35-49

What is the reference range for MCV

80-100

What is the reference range for MCH

24-36

What is the reference range for MCHC

32-36

What is the reference range for RDW

11.5-14.5

What is the reference range for PLT

150-450

What is the reference range for NEUT

50-70

What is the reference range for LYMPH

18-42

What is the reference range for MONO

2-11

What is the reference range for EO

1-3

What is the reference range for EO

0-2

Formula for RETIC %

# of RETIC/ # of RBC * 100

Formula for Absolute Retic count

RETIC % X RBC count / 100

What is the formula for RPI

Corrected RETIC count/ Maturation Correction Factor

What is the formula for corrected RETIC count

RETIC % x PT HCT/ Normal HCT

What is anemia?

A condition with decreased hemoglobin, often accompanied by a reduced number of red blood cells.

What are erythrocytosis and polycythemia?

An increase in red blood cells in circulation above normal levels.

What is relative anemia or erythrocytosis caused by?

a decrease in plasma volume, meaning the concentration of red blood cells appears higher than normal because there is less fluid in the blood, typically due to dehydration from factors like vomiting, diarrhea, excessive sweating, or not drinking enough fluids; essentially, it's a "relative" increase in red blood cells rather than an actual increase in their number. 

How does plasma volume affect red cell mass (RCM) in relative anemia?

Fluid shifts from the intravascular to the extravascular compartment, decreasing plasma volume and increasing the relative concentration of red blood cells.

In what conditions is relative anemia commonly seen?

Pregnancy and hyperproteinemia.

What is absolute anemia?

A true decrease in red cell mass

What are the categories of hypoproliferative anemias?

• Anemia of bone marrow failure

• Anemia of systemic disorders

What are the types of maturation disorders in anemia?

• Anemia of abnormal nuclear development

• Anemias of abnormal iron metabolism

• Anemias of abnormal globin development (e.g., Thalassemias)

What are the types of hemolytic disorders?

• Hereditary hemolytic anemias

• Hemoglobinopathies

• Membrane and enzyme disorders

• Acquired hemolytic anemias

  • Non-Immune

  • Immune

What are the types of anemias of blood loss?

• Acute blood loss

• Chronic blood loss

What are the symptoms of mild anemia?

• No symptoms

• Palpitations and dyspnea

• Tachycardia, shortness of breath, headache

• Pallor of the skin

• Leg cramps, dizziness, fatigue, and insomnia

• Tissue hypoxia, coma, and death (in severe cases)

What tests are used for anemia diagnosis?

• CBC with cell indices (HB, HCT, RBC, MCV, MCH, MCHC)

• Reticulocyte count

• Blood smear examination

• Bone marrow examination

• Other: Urinalysis & Occult blood

What is effective erythropoiesis?

When ≥90% of progenitor cells mature into differentiated RBCs.

What is ineffective erythropoiesis?

When progenitor cells are defective and fail to produce mature RBCs.

What is insufficient erythropoiesis?

When there is a quantitative absence of RBC progenitor cells.

What is the etiology of anemia

The cause or underlying pathophysiologic mechanism that leads to the anemia

How is anemia classified morphologically?

Based on RBC indices and direct examination of RBC morphology, including size and hemoglobin content.

What RBC indices are used for classification?

• Mean Corpuscular Volume (MCV)

• Mean Corpuscular Hemoglobin (MCH)

• Mean Corpuscular Hemoglobin Concentration (MCHC)