HEAMATOLOGICAL INDICES AND BONE

MARROW BIOPSY

HEMATOCRIT

Hematocrit is a measure of the percentage of

the total blood volume that is made up by the

red blood cells

The hematocrit can be determined directly by

centrifugation (“spun hematocrit”)

The height of the red blood cell column is

measured and compared to the column of the

whole blood

CENTRIFUGED BLOOD (NORMAL)

Red blood cells

Buffy coat (WBCs and Platelets)

Plasma

Normal Hct in adult males

40-54%

Normal Hct in adult females

34-51%

CENTRIFUGED BLOOD (ADULT MALE OR FEMALE)

WHAT IS YOUR DIAGNOSIS?

Anemia – there is a low percentage of RBCs

(low hematocrit)

RBCs

Buffy coat

Plasma

CALCULATING THE HEMATOCRIT

More commonly the Hct is calculated directly

from the RBC and MCV

Hematocrit % = RBC (cells/liter) x MCV (liter/cell)

Because the Hct is a derived value, errors in

the RBC or MCV determination will lead to

spurious results

MEAN CORPUSCULAR VOLUME

The MCV is a measure of the average volume,

or size, of an RBC

It is determined by the distribution of the red

blood cell histogram

The mean of the red blood cell distribution

histogram is the MCV

Cell Size (fl)

Number

Of

cells

60 120

MCV

RED CELL DISTRIBUTION HISTOGRAM

USE OF MCV RESULT

The MCV is important in classifying anemias

Normal MCV = normocytic anemia

Decreased MCV = microcytic anemia

Increased MCV = macrocytic anemia

Cell Size (fl)

Number

Of

cells

60 120

MCV

RED CELL DISTRIBUTION HISTOGRAM

Microcytic

Red blood cells

Macrocytic

Red blood cells

PURPOSE FOR PERFORMING RBC INDICES:

( I ) Morphologic classification of anaemia.

( II ) To correlate Hb estimation and RBC count

I. Mean cell volume ( MCV ) :MCV is the average volume of red cells. It is expressed in

cubic micrometers or femtolitre.

MCV = PCV x 10 / RBC count in millions/cmm.

It is expreesed in femtolitre.

Normal range: 80 - 96 micrometer or femtolitre.

II. Mean cell haemoglobin ( MCH ) :MCH is the content (weight) of haemoglobin of average red cell.It is expressed in picograms or

micromicrograms.

MCH = Hb (in gms/ 100ml)/ RBC count( in millions/cmm) x 10.

It is expressed in picogram or micromicrogram.

Normal range: 27 - 33 picograms or micromicrograms.

III. Mean cell Heamoglobin concentration ( MCHC ):It is the average concentration of haemoglobin in a

given volume of packed red cells.

MCHC = Hb (in gms/100ml) / PCV - expressed in percentage.

Normal range :33 to 36 %

Abnormal Indices :

In microcytic anaemias, indices are decreased , with MCV upto 50 fl, MCH upto 15 pg, MCHC upto 22 %

In macrocytic anaemias, the values may be as high as MCV upto 150fl, MCH upto 50 pg with normal or decreased MCHC.

The MCHC increases only in spherocytosis, it rarely is over 35 %.

BONE MARROW BIOPSY

BONE MARROW

Bone marrow differentiates into myeloid, erythroid and lymphoid cell lineages under the influence of cytokines or growth factors.

Function: supply mature hematopoietic cells into peripheral blood and respond to demands

BONE MARROW

Highly vascularized loose

connective tissue

Organized around bone

vasculature

Located between

trabeculae of spongy bone

Composed of 2 major

compartments

Hematopoietic

Vascular

INDICATIONS FOR BM EVALUATION

Hematological and nonhematological disorders often requires BM evaluation for

Diagnosing

Managing

Making prognoses

Following up on disorders

Bone marrow should be evaluated together with

Peripheral blood counts

Peripheral blood smear

INDICATIONS FOR BONE MARROW STUDY :-

In microcytic anemias - evaluation of the iron stores and sideroblasts allows categorization of the anemia i.e. iron deficiency , anemia of chronic diseases,sideroblasticanemia.

In macrocytic anemias - to confirm whether the process is megaloblastic or not.

In normocytic anemias without an increased reticulocyteproduction index - evaluation for quantitative or qualitative abnormalities in erythropoiesis .eg. pure red cell aplasia, myelodysplasia

In neutropenia , thrombocytopenia or pancytopenia –

Helpful in assessing the presence and normality of the precursor cells in each series

One can assess -

Decreased production

Impaired maturation

Increased destruction

as the mechanism of the disorder.

In cytopenias - sometimes presence of

Leukemia or other hematologic neoplasia.

Confirmation of diagnosis in immunoglobulin

abnormalities -

Plasma cell myeloma

Macroglobulinemia

Trephine biopsy is indicated for -

For assessing marrow cellularity

Following the administration of antineoplasticdrugs.

To assess the status of engraftment

Following bone marrow transplantation

To investigate the patients with

Infectious diseases

Metabolic disorders

Evaluation of patients with

Malignant lymphoma

Leukemia

Metastatic tumor

Granulomatous disorders

Myelofibrosis

Aplastic anemia

Plasma cell dyscrasias

BONE MARROW PROCEDURE

Sites of hematopoiesis

Differ by age

Certain disease states

Red marrow can extend into long bones

Cellularity within red marrow decreases with age

Adipose tissue replaces hematopietic tissue

BONE MARROW PROCEDURE

Marrow specimens

After adolescence

Posterior superior iliac

crest

Occasionally sternum and

anterior iliac crest

< 2 years of age

Anterior tibia

Older children

Spines of the lumbar

vertebral bodies L1 and

L2

BONE MARROW PROCEDURE

Equipment Use sterile technique

Make direct smears from the aspirate

Make crush smears from the marrow spicules

Place extra aspirate into anticoagulated tubes

Performance of the preliminary exam and processing

BONE MARROW EQUIPMENT

Bone marrow aspirates and biopsies

Obtained using disposable needles

Jamshidi trephine needle (8 or 11 gauge)

Sterile technique always used

JEMSHIDI TREPHINE

SALAH ASPIRATION

NEEDLE

PROCESSING THE SPECIMEN IN THE

LAB Place EDTA specimen (liquid aspirate) in Wintrobe tube and

centrifuge at low speed.

Measure layers formed by centrifugation

FPV - fat and perivascular

used for iron stain

Plasma

Buffy coat (myeloid:erythroid cells- M:E)

Normal is 4:1.

M:E is the ratio between all granulocytes and their precursors and all nucleated red cell precursors.

RBC’s

PROCESSING THE SPECIMEN :

Prepare and stain ME smears.

Deliver clot remaining in syringe and biopsy to histology for processing.

Deliver other specimens obtained such as viral, fungal or routine culture specimens to microbiology.

INFORMATION DERIVED FROM SPECIMENS

Direct smear from syringe tip - evaluation of cellular morphology with Wright’s stain

Particle (crush) smear - evaluation of cellularity and the relationship of cells to each other

M:E smear - evaluation of hematopoietic cells and M:E ratio

Biopsy If marrow cannot be aspirated (“dry tap”), this is the only specimen for examination

Examination for malignancy for clinical staging of lymphomas and cancers

Examination of the architecture of the bone marrow and the cells in their natural relationship to each other

Trephine imprint (touch prep) - examination of cells with Wright’s stain; may be the only source to study cellular detail if an aspirate is not obtained

Thank You