Red cell morphological evaluation
description
Transcript of Red cell morphological evaluation
LECTURE 5 EVALUATION OF BLOOD
Undergraduate Course in Veterinary Clinical PathologySocrates-Erasmus Programme
Haematology
5-1
LECTURE 5. EVALUATION OF BLOOD SMEAR RBCs AND RETICULOCYTES
OVERVIEW
1. RBC morphological evaluation
5-2
2. Reticulocyte count and evaluation
1. RBC MORPHOLOGICAL EVALUATION
5-3
EVALUATION
DOG CAT
VARIATIONS IN SPECIES
5-4
-Large erythrocytes-Size uniformity-Central pallor
-Smaller erythrocytes-Anisocytosis
-Scarce central pallor
HORSES RUMINANTS
VARIATIONS IN SPECIES
5-5
Rouleaux(sedimentation tendency) Anisocytosis and crenation
EVALUATION OF RBC NUMBER AND SIZE INDIFFERENT ANIMAL SPECIES
20
25
30
70
80
90
100
5-6
NUMBER VOLUME
0
5
10
15
RBC
1012
/l
Hund Katze Pferd Schwein Rind Schaf ZiegeTierart
n = 46 6161 105 176 141 181 1720
10
20
30
40
50
60
MC
V fl
Hund Katze Pferd Schwein Rind Schaf ZiegeTierart
n = 46 6161 105 176 141 181 172
dogs cats horses pigs cattle sheep goatsspecies
dogs cats horses pigs cattle sheep goatsspecies
ABNORMALITIES OF RBCs MORPHOLOGY1. Abnormalities in size
-MACROCYTOSIS-MICROCYTOSIS
2. Abnormalities in colour -POLYCHROMASIA-HYPOCHROMASIA
5-7
-HYPOCHROMASIA 3. Abnormalities in shape
-SPHEROCYTOSIS -NON-SPECIFIC FINDINGS
4. Abnormalities in distribution -ROULEAUX-AGGLUTINATION
5. Inclusion Bodies and infectious agents
ReticulocytesMACROCYTOSIS
FeLV
ABNORMALITIES IN SIZE
5-8
MICROCYTOSIS Iron deficiency
ABNORMALITIES IN SIZE
5-9
Reticulocytes and spherocytesin a dog with immune-mediatedhaemolytic anemia
Macrocytic (but non-regenerative)anemia in FeLV infected cat
ABNORMALITIES IN COLOUR
POLYCHROMASIA HYPOCHROMASIA
5-10Reticulocyte Iron deficiency
-SPHEROCYTOSIS (MARKER OF IMMUNE-MEDIATED HAEMOLYTICANAEMIA)
-NON-SPECIFIC FINDINGS
ABNORMALITIES IN SHAPE (POIKILOCYTOSIS)
5-11
- Crenation- Acanthocyte- Schistocyte/fragmentocyte- Target Cell
Spherocytes
5-12
Crenation Numerous pin-point projections
5-13
Acanthocytes (few irregular elongations of RBC border with rounded ends often forming a bud)
5-14
Schistocytes. (erythrocyte fragmentation)
5-15
Target cell
5-16
Rouleaux
- normal finding in horses- indicates inflammationin small animals
ABNORMALITIES IN RBC DISTRIBUTION
5-17
in small animals
Agglutination
Macroscopic Microscopic
5-18
- can suggest immune-mediated haemolytic anaemia
HOWELL-JOLLY BODIES
BASOPHILIC STIPPLING
NUCLEATED ERYTHROCYTES
INCLUSION BODIES AND INFECTIOUS AGENTS
Signs ofregeneration
5-19
HEINZ BODIES
INFECTIOUS AGENTS (Babesia, Mycoplasma haemofelis)
Nucleated RBCs
5-20
and Howell-JollyBodies
Basophilic stippling
5-21
HeinzBodies
5-22
HeinzBodies
5-23
Infectious agents
5-24
Babesia canis Haemobartonella felis(Mycoplasma haemofelis)
2. RETICULOCYTE COUNT AND EVALUATION
5-25
EVALUATION
Reticulocytes are young (immature) erythrocytes prematurely released to blood from the bone marrow in some anaemias.
CLINICAL APPLICATIONS: Evaluation of erythropoiesis in bone narrow. Differentiation of regenerative and non regenerative anaemia
5-26
TECHNIQUES OF DETECTION: -Romanowsky stains-Supravital stains:
• New methylene blue • Brillant cresyl blue
Differentiation of regenerative and non-regenerative anaemia.
ROMANOWSKY STAINS
5-27
In dogs, an average of >10 polychromatic red cells per OIF suggests a marked regenerative response
NEW METHYLENE BLUE (NMB) STAIN
Reticulocytes are non-nucleated erythrocytes in which NMBstain precipitates in RNA-protein complexes
5-28
ABSOLUTE RETICULOCYTE COUNT
- Manual
A t t d ( h t l i l l )
5-29
- Automated (some haematological analysers)
MANUAL ABSOLUTE RETICULOCYTE COUNT
1. Count number of reticulocytes per 500-1000 erythrocytes (blood smear)
-e.g. 10 reticulocytes / 500 erythrocytes
2 Calculate % of reticulocytes
5-30
2. Calculate % of reticulocytes
-e.g. Reticulocyte % = 10 x 100 / 500 = 2
3. Calculate absolute reticulocyte count based on erythrocyte count from the haematology analyser
-e.g. Absolute reticulocyte count (109/L)= Reticulocyte % x Erythrocyte count / 100
If absolute reticulocyte count:
INTERPRETATION
5-31
Dogs >60x 109/LA sign of regeneration
Cats>50x 109/L
RETICULOCYTE PRODUCTION INDEX:CALCULATIONS
- Corrected reticulocyte percentage (CRP)
CRP= % reticulocytes x PCV of sample/normal PCV
5-32
- Reticulocyte Production Index (RPI)
RPI= CRP/Maturation Index(MI) PCV MI (days)0.45 1
(values for dogs) 0.35 1.50.25 20.15 2.5
- Corrected reticulocytes percentage (CRP)
Dog with PCV=0.15L/L and reticulocytes =15%
RETICULOCYTE PRODUCTION INDEX:PRACTICAL EXAMPLE
5-33
CRP= 0.15 x 0.15/0.45 = 5%
- Reticulocyte Production Index (RPI)
RPI= 5/2.5 =2
INTERPRETATION
RPI > 3 Very good regeneration
RPI = 1-3 Good regeneration
5-34
RPI = 1-3 Good regeneration
RPI < 1 Inadequate regeneration
EXAMPLES OF USE OF RETICULOCYTE PARAMETERS IN DOGS
Units Case 1 Case 2 Case 3
Hct/PCV L/L 0.15 0.15 0.15 RBC count x1012/L 2.0 2.0 2.0 Reticulocytes % 3 12 25
5-35
y % 3 12 25 Reticulocytes x109/L 60 240 500 CRP --- 1 4 8.33 RPI --- 0.4 1.6 3.33 Diagnosis
non-regenerative
anemia
good regenerative
anemia
highly regenerative
anemia
SPECIES VARIATIONS: IN CLINICALLY HEALTHY ANIMALS
- Dogs. Low number of reticulocytes (<1%), aggregate only
- Cats Two types of reticulocytes:
5-36
Cats. Two types of reticulocytes:
• aggregate: blue stained coarse clumping (0.5% of erythrocytes)
• punctate: small, blue stained dots (1-10%).
- Ruminants and horses. Virtually no reticulocytes in blood.
SPECIES VARIATION: in anaemicanimals
- Canine. Strong reticulocyte response in regenerative anaemias.
Aggregated reticulocytes (indicate recent response)
5-37
Aggregated reticulocytes (indicate recent response)- Feline.
Punctated reticulocytes (indicate response to anaemia occurring 3-4 weeks previously)
- Ruminants and horses. Reticulocytes may not appeareven in very severe anaemias