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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
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