Incorporating Differentials Into Every Complete Blood Count. Paige Flowers, LVT Dogwood Veterinary Internal Medicine

Transcription

1 Incorporating Differentials Into Every Complete Blood Count Paige Flowers, LVT Dogwood Veterinary Internal Medicine

2 Complete Blood Count Diagnostic performed to evaluate the quantity and morphology of the cellular components of blood. Automated cell count PCV/TS Manual Differential

3 Sample Collection and Handling Fill EDTA tubes until vacuum flow stops Ensures appropriate blood volume to anticoagulant ratio Prevents overfilling If not analyzed within 2-3 hours, EDTA blood should be refrigerated Minimal changes in refrigerator for up to 24 hours

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5 Automated Cell Counters Impedance Principle {aka: The Coultier Principle} Quantifies cells Identifies cells by size and density

6 Automated Cell Counters Platelet-erythrocyte histograms used to evaluate for mechanical errors Overlap in the size of platelets and erythrocytes indicates the machine cannot differentiate between the two

7 A clear separation valley must be identified between erythrocyte and platelet peaks

8 Automated Cell Counters Laser Light Scatter Laser detection system in a flow cytometer to measure size and internal complexity of cells Able to make distinctions that are undetectable using impedance

9 Cytogram

10 PCV vs HCT HCT (RBCs x MCV) 10 PCV Centrifugation of blood to pack erythrocytes and determine a packed cell volume The variation between HCT and PCV should not exceed 5% Suggests technical error

11 The Differential Complements automated cell counters Often provides diagnostic information that an automated cell counter cannot Even without an automated cell count

12 The Blood Smear Prepare immediately Monolayer Provides optimal morphologic detail Good distribution Stains well Cells lay flat

13 The Blood Smear Only cells with sufficient morphologic detail should be included in the differential cell count A large percentage could be cause for concern

14 LEUKOGRAM Total and differential leukocyte count Assessment of WBC morphologic features.

15 Neutrophils

16 Neutrophils Toxic neutrophils Indicates more severe disease, a worse prognosis and longer hospital stays Moderate to severe toxic changes can cause signs such as fever, vomiting, diarrhea or shock like symptoms

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18 Eosinophils Orange - pink granules Shorter and less segmented than neutrophil nuclei Cytoplasm, if visible, is pale blue.

19 Basophils Canine ribbon-like nucleus gray-lavender hue Feline small, slightly oval granules pale lavender

20 Monocytes Variable in size and appearance Usually largest leukocyte Nucleus can be round to kidneyshaped to pseudolobulated

21 Lymphocytes small (mature) cells round nuclei smooth, dense chromatin small rim of light blue cytoplasm

22 Lymphocyte sizes Lymphocyte size Nucleus size relative to neutrophil Small Intermediate Large Nucleus of lymphocyte can fit inside a neutrophil Nucleus of lymphocyte is the same size as a neutrophil Neutrophil can fit inside the nucleus

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26 Reactive Lymphocytes

27 Erythrogram Assessment of red blood cell numbers Assessment of morphologic features

28 Erythropoesis

29 Spherocytes More spherical than normal disc shaped erythrocytes Do not lay flat - appear smaller Darker in color Lack central palor

30 Autoagglutination Immune-induced aggregation of erythrocytes into clusters

31 Target Cell Resemble a bullseye target Regenerative anemia Iron deficiency anemia

32 Acanthocytes Club shaped spicules protruding from erythrocyte

33 Howell-Jolly Body Blue in color Perfectly round Small fragments of nonfunctional nucleus

34 Heinz Body Intracellualr inclusions Small, round protrusion on the edge of erythrocytes

35 Mycoplasma Small, blue cocci or rod-like on the edges or across the faces of erythrocytes

36 Immature neutrophil vs monocyte vs reactive lymphocyte

37 Immature Erythrocyte vs Lymphocyte

38 Thrombogram Assessment of platelet numbers Assessment of platelet size Assessment of morphologic features

39 Macroplatelets Large, immature platelet

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41 Willard, DVM, MS, DACVIM, Michael, and Harold Tvedten, DVM, PhD, DACVP, DACVCP. "The Complete Blood Count, Bone Marrow Examination and Blood Banking." Small Animal Clinical Diagnosis by Laboratory Methods. Fifth ed. St. Louis: Elsevier, Print. "Hemogram Basics." EClinpath. Cornell University College of Veterinary Medicine, Web. 16 Oct