Haematology Parameter 2 PARAMETER LASERCYTE QBC VETAUTOREAD IMPEDANZ

Haematology

Parameter 2 PARAMETER LASERCYTE QBC VETAUTOREAD IMPEDANZ SYSTEM Hct Yes Yes Hgb Yes Yes RBC Yes Retics Yes MCV Yes RDW Yes MCHC Yes MCH Yes WBC Yes LYM Yes ( Small ) MONO Yes ( Middle ) NEU Yes EOS Yes Dogs and Cows BASO Yes PLT Yes PCT Yes PDW Yes MPV Yes Up to 4% Yes Yes ( Large ) Yes FIBRINOGEN Yes NRBC’s Yes © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential Yes

Eosinophils Eosinophilia l l l Most frequent causes l Parasitic and allergic processes l Heartworm, Strongyle, Lung Flukes l Feline asthma, Flea bite dermatitis Least frequent cause l Neoplasia, Fungal Infecion l Viral Infection ( Fe. LV ) Eosinopenia l 3 When concurrent with lymphopenia is usually due to stress © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

What can cause changes in blood values? l Infections l l l l l 4 Bacteria Viral Funghi Inflammation Intoxication Stress Anaemia Tumors Bleeding disorders Autoimmun diseases © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Why run Haematology inhouse? • Blood samples consist of living cells and should therefore be analysed as quickly as possible, to avoid: § Changes in cells because of storage and transport § To minimise artefacts which can develop if the sample has contact to EDTA for a longer period of time § So treatment decisions are based on todays situation and not yesterdays 5 © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Fresh Sample versus 48 hr Sample 6 © 2004 IDEXX Laboratories, Inc. , IDEXX

CBC l Red cells (Erythrocytes) l White cells (Leucocytes) l Granulocytes Neutrophiles Eosinophiles Basophiles l Agranulocytes Lymphocytes Monocytes l 7 Platelets (Trombocytes) © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

White differentials • Typical “ 2 part” Diff Agranulocytes Granulocytes • Typical “ 5 part” Diff • Typical “ 3 part” Diff 8 Lymphocytes Monocytes Granulocytes © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential Lymphocytes Monocytes Neutrophile Grans Eosinophile Grans Basophile Grans

What differentials do you get with. . QBC Autoread Laser. Cyte ? Impedance System

Why can’t an impedance system give you a 5 part diff SIZE MATTERS !

Laser. Cyte…. l l l l 11 Cells focused into a stream that passes through a laser light that interrogates them. Light scatter is sensed by four photodiodes. Time of flight measurement also taken. Initial RBC count and platelet count taken. The RBC’s are then lysed using a mild agent. 5 part differential then performed quali. Beads are run with every sample. These act as an internal standard for quality assurance. © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Laser. Cyte Technologie. . . 12 © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

QBC Autoread… 13 l The QBC uses centrifugation to separate cells by density. l The ‘float’ in the QBC tube reduces the volume of lumen in the area of the buffy coat. l This causes the cells to be spread out over a greater distance. l Cells take up the ‘acridine orange’ present in the tube (DNA and RNA/Lipoproteins). l Cell types are differentiated by the location and intensity of dye. © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

QBC Vet. Autoread 14 © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Coulter® Principle l 15 Impedance counters rely on the Coulter principle. When a particle passes through a narrow orifice, it causes a change in resistance. The magnitude of the change corresponds to cell size and the number of changes corresponds to cell size. © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Interfering Substances 3 Part Impedance Technology l l 16 Giant / Clumped Platelets l Results in erroneously low platelet counts. Erroneously high WBC count. Can also be misclassified as RBC’s. n. RBC’s and unlysed RBC’s l Unable to classify n. RBC’s result in erroneously high WBC count Excessive eosinophils, metamyelocytes, blasts and plasma cells. l Can cause erroneous monocyte count Leukaemia and chemotherapy l Harsh lysing agent can damage fragile cells © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Interfering Substances. . l High WBC count l l Agglutinated red cells l l Can cause erroneously low RBC and can trap platelets. Microcytic cells and fragments l 17 WBC’s counted during RBC count. This can effect the red cell parameters. (Hct, RDW, MCV and RBC) Can effect platelet count © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Interfering Substances…. l l l 18 How does the operator know if you have abnormal cells present that may affect the results ? How do they know if the results are due to the clinical condition or erroneous reading caused by abnormal cells? Would you trust a system that could not flag ‘suspect’ results ? © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential

Parameter 19 PARAMETER LASERCYTE QBC VETAUTOREAD IMPEDANZ SYSTEM Hct Yes Yes Hgb Yes Yes RBC Yes Retics Yes MCV Yes RDW Yes MCHC Yes MCH Yes WBC Yes LYM Yes ( Small ) MONO Yes ( Middle ) NEU Yes EOS Yes Dogs and Cows BASO Yes PLT Yes PCT Yes PDW Yes MPV Yes Up to 4% Yes Yes ( Large ) Yes FIBRINOGEN Yes NRBC’s Yes © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential Yes

ABC Analyser – The Bad ! l l l No retic information 3 Part Diff Impedance technology l l l 20 Interfering substances 160 cycles include calibration / flushes / start up runs etc No data storage Few or no flags on abnormal samples Needs recalibrating every 6 months Different smart card per species © 2004 IDEXX Laboratories, Inc. , IDEXX Confidential