农业类兽医临床病理(英)课件

1、Veterinary Clinical Pathology兽医临床病理学Prof. Zhaoxin TangCollege of Veterinary Medicine, South China Agricultural University, Guangzhou, China , 5106422021/02/241Veterinary Clinical Pathology兽PrefaceVeterinary Clinical Pathology:Veterinary Laboratory MedicineInclude:1 Clinical Hematology2 Clinical bioc

2、hemistry3 Clinical cytology4 Clinical microbiology5 Clinical parasitology6 Clinical toxicology2021/02/242PrefaceVeterinary Clinical PatPrefaceGeneral Laboratory concepts Veterinarians have many choices regarding laboratory testing. Important factors include:-Need and usefulness-Practicality-Cost-eff

3、ectiveness-Accuracy-Turnaround time2021/02/243PrefaceGeneral Laboratory concComplete Blood Count and Bone Marrow Examination:general comments and selected techniquesComplete blood countQuantitation techniquesBlood smear analysisOther determinationsBone marrow examinationBone marrow biopsy and aspira

4、te2021/02/244Complete Blood Count and Bone Complete blood count (CBC)CBC is a pro tests used to describe the quantity and quality of the cellular elements in blood and a few substances in plasma.CBC is a cost-effective screen the detects many abnormalities and disease conditions.Bone marrow examinat

5、ion is used in selected instances to answer questions the more readily available CBC cannot.2021/02/245Complete blood count (CBC)CBC Quantitation TechniquesSample submissionMicrohemotcritHemoglobin concentrationCell countsAbsolute nucleated RBC countAutomated hematology cell counters2021/02/246Quant

6、itation TechniquesSample Blood Smear AnalysisMaking the smearStainsEvaluating blood smears -platelet morphology -leukocyte morphology -leukocyte estimation -leukocyte differential count -erythrocyte morphology2021/02/247Blood Smear AnalysisMaking theBone Marrow ExaminationBone marrow is usually exam

7、ined to answer certain question that arose from evaluating the CBC.Indications for bone marrow examination include: -nonregenerative anemia -Persistent neutropenia -Persistent thrombocytopenia -Unexplained polycythemia or thrombocytosis -Atypical cells in blood2021/02/248Bone Marrow ExaminationBone

8、maErythrocytesBasic concepts of erythrocyte function,metabolism, production and breakdownHeme synthesisGlobin synthesisIron metabolism2021/02/249ErythrocytesBasic concepts of Erythrocyte metabolismEmbden-meyerhof pathway -Glycolysis generates ATP and NADHPentose phosphate pathway -This pathway produ

9、ces NADPHMethemoblobin reductase pathway -Methemoglobin(Fe3+) cannot transport oxygenRapoport-luebering pathway -2,3 diphosphoglycerate(2,3 DPG)2021/02/2410Erythrocyte metabolismEmbden-mRed blood cells The fundamental stimulus for production of red blood cells (erythropoiesis) is erythropoietin(红细胞生

10、成素）, a glycoprotein produced by the kidneys in response to renal tissue hypoxia. Other hormones, such as corticosteroids, thyroid hormone and androgens, stimulate the production or release of erythropoietin but have no intrinsic erythropoietic activity.The average lifespan of a circulating erythrocy

11、te is 110-120 days in the dog and 68 days in the cat. Aged or damaged red cells are removed primarily by macrophages in the liver, spleen and bone marrow. 2021/02/2411Red blood cells2021/02/2411NeutrophilsThe production of neutrophils, eosinophils and basophils is termed granulopoiesis. The neutroph

12、ils in the bloodstream either circulate freely (the circulating pool) or adhere to the vascular endothelium (the marginal pool). In the dog the marginal pool and the circulating pool are approximately equal in size, whilst in the cat the marginal pool is two to three times larger than the circulatin

13、g pool. There is a continual exchange of cells between these two pools. The half-life of circulating neutrophils is only 6-14 hours, after which time they leave the circulation and pass into the tissue pool. The circulating time is shortened during acute infections as neutrophils pass to the site of

14、 infection in the tissues. The main function of the neutrophil is the phagocytosis of pyogenic bacteria. 2021/02/2412Neutrophils2021/02/2412Lymphocytes Lymphoid primitive stem cells divide and differentiate into pre-B lymphocytes and pre-T lymphocytes in the bone marrow. Pre-T lymphocytes mature and

15、 proliferate into T cells in the thymus. Pre-B cells proliferate in the bone marrow and migrate to peripheral lymphoid organs (spleen and lymph nodes) where further proliferation takes place. Platelets Platelets are produced from the cytoplasm of megakaryocytes Once in the circulation, platelets sur

16、vive for 8-12 days. Up to 20-30% of circulating platelets can be sequestered in the spleen; the figure may be a high as 90% if there is splenomegaly. Old or damaged platelets are removed from the circulation by the spleen, liver and bone marrow. 2021/02/2413Lymphocytes2021/02/2413ROUTINE HAEMATOLOGY

17、The complete blood count is an integral part of the diagnostic investigation of any systemic disease process. It consists of two components: A quantitative examination of the cells, including : packed cell volume (PCV) total red cell count (RBC) total white cell count(WBC) differential white cell co

18、unt platelet count mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total plasma protein concentration.A qualitative examination of blood smears for changes in cellular morphology. 2021/02/2414ROUTINE HAEMATOLOGYThe compleTable 1 R

19、eference values for red cell indices DogsCatsTotal red blood cells(x1012/L)5.58.55.010.0Haemoglobin(g/dl)12.018.08.015.0PCV (L/L)0.370.550.260.45MCV (fl)60.077.039.055.0MCH (pg)19.524.512.517.5MCHC (g/dl)32.037.030.036.0ROUTINE HAEMATOLOGY2021/02/2415Table 1 Reference values forRED BLOOD CELL INDICE

20、SMCV(fl飞升)= PCV (L/L) 1000/ total red cells ( 1012/L) MCH (pg皮克) = total haemoglobin (g/dl) 10/ total red blood cells ( 1012/L) MCHC (g/dl) = total haemoglobin (g/dl)/PCV (L/L) RBC indices are helpful in the classification of certain anemias.ROUTINE HAEMATOLOGY2021/02/2416RED BLOOD CELL INDICESMCV(f

21、l飞升Differential white cell countsThe differential white cell count is performed by counting 200 leucocytes in a blood smear. The cells are counted along the long edge of the smear, using the battlement meander method: four high-power fields are counted in one direction, then four more in a direction

22、 at right angles to the first, and so on, following the shape of a battlement. The percentage of each type of cell is determined. This percentage is then multiplied by the total white cell count to obtain an absolute count for each cell type. ROUTINE HAEMATOLOGY2021/02/2417Differential white cell co

23、untsPlasma protein concentration(Reference range: 60-80 g/1 for the dog and cat) Total plasma protein (TPP) and PCV should be interpreted together. Qualitative examination of a blood smearA blood smear should always be evaluated when automated cell counts are made or when in-practice instrumentation

24、 is limited to a centrifuge for PCV Preparation of a blood smear A small drop of blood is placed on one end of a glass slide, using a capillary tube. A spreader slide (made by breaking off the comer of another slide, after scoring it with a glass cutter or diamond writer) is placed on to the slide h

25、olding the blood drop, in front of the drop and at an angle of 20-40. ROUTINE HAEMATOLOGY2021/02/2418Plasma protein concentrationROANAEMIAAnaemia is characterized by an absolute decrease in red cell count, haemoglobin concentration and PCV. Acute haemorrhage Acute haemorrhage may be due to trauma or

26、 surgery, bleeding gastrointestinal ulcers or tumours, rupture of a vascular tumour (e.g. splenic haemangiosarcoma), or a coagulopathy (e.g. warfarin toxicity). Immediately following acute haemorrhage the red cell parameters, including PCV, are normal because both red cells and plasma have been lost

27、 in proportion. Compensatory mechanisms such as splenic contraction may further offset any fall in PCV. The PCV falls when blood volume is replaced by interstitial fluid and so does not indicate the full magnitude of blood loss for at least 24 hours after the onset of haemorrhage. ROUTINE HAEMATOLOG

28、Y2021/02/2419ANAEMIAROUTINE HAEMATOLOGY202 Chronic haemorrhageChronic external blood loss (e.g. chronic gastrointestinal haemorrhage, renal or bladder neoplasia) initially results in a regenerative anaemia but gradually the anaemia becomes non-regenerative as the iron stores become depleted. Young a

29、nimals become iron-deficient more bone marrow is already very active producing red cells quickly than adults following blood loss, partly because they have low iron stores and partly because their to match their growth rate and so has less capacity to increase its rate of haemopoiesis. Haemolytic an

30、aemiasMost cases of haemolytic anaemia are immune-mediated. In the dog most cases of immune-mediated is haemolytic anaemia (IHA) are primary (idiopathic) and are termed autoimmune haemolytic anaemia (AIHA). IHA may occur in association with: drugs(e.g. potentiated sulphonamides); lymphoreticular dis

31、eases (e.g. lymphoid leukaemia); systemic lupus erythematosus; or infections (e.g. Babesia, bacterial endocarditis). ROUTINE HAEMATOLOGY2021/02/2420 Chronic haemorrhageROUTINE HDISORDERS OF WHITE CELL NUMBERNeutrophiliaFigure 3.20 Causes of neutrophilia Physiological response (fear, excitement, exer

32、cise) Stress/corticosteroid-induced Acute inflammatory response: bacterial infection (localized or generalized), immune-mediated disease, necrosis,e.g.pancreatitis, neoplasia, especially with tumor necrosis. Chronic granulocytic leukaemia Neutrophil dysfunction Paraneoplastic syndromes 2021/02/2421D

33、ISORDERS OF WHITE CELL NUMBERNeutropenia The three main causes of neutropenia are: An overwhelming demand for neutrophils Reduced production of neutrophils in the bone marrow Defective neutrophil maturation in the bone marrow. An overwhelming demand for neutrophils may occur with peracute bacterial

34、infections, especially Gram-negative sepsis and endotoxaemia. Other possible causes include peritonitis, pyometra（子宫蓄脓）, aspiration pneumonia and canine parvovirus infection. DISORDERS OF WHITE CELL NUMBER2021/02/2422Neutropenia DISORDERS OF WHITEEosinophilia Eosinophils are distributed in the body

35、among various pools in a similar way to neutrophils, although the bone marrow storage pool is minimal. Eosinophils circulate in the bloodstream for only a few hours before entering the tissues, where they may live for several days. Their two main functions are to kill parasites and to regulate aller

36、gic and inflammatory reactions. Eosinopenia Eosinopenia in combination with lymphopenia occurs following stress, administration of corticosteroids and in spontaneous hyperadrenocorticism (Cushings syndrome). Basophilia Basophils contain inflammatory mediators such as histamine and heparin and functi

37、on in a similar manner to mast cells in hypersensitivity reactions. DISORDERS OF WHITE CELL NUMBER2021/02/2423Eosinophilia DISORDERS OF WHITLymphocytosis Causes of lymphocytosis 1. Physiological lymphocytosis, with concomitant neutrophilia, in response to excitement (especially cats) 2. Strong immun

38、e stimulation (e.g. in chronic infection, viraemia or immune-mediated disease) 3. Chronic lymphocytic leukaemia 4. Hypoadrenocortiscism (lymphocytosis may be associated with an eosinophilia) 5. Increased numbers of large reactive lymphocytes may occur transiently following vaccination 6. Young anima

39、ls have a higher lymphocyte count than adult animalsDISORDERS OF WHITE CELL NUMBER2021/02/2424Lymphocytosis DISORDERS OF WHILymphopeniaCauses of lymphopenia are listed.StressGlucocorticoid therapyHyperadrenocorticismChylothorax (loss of lymphocytes into the pleural space)Lymphangiectasia (loss of ly

40、mphocytes into the gut)Acute phase of most viral infections (e.g. canine distemper, parvovirus, FeLV)Septicaemia/endotoxaemiaDISORDERS OF WHITE CELL NUMBER2021/02/2425LymphopeniaStressDISORDERS OF DogsCats percentageAbsolute valuepercentageAbsolute value(10/Total WBCN/a617N/a5.519.5Band neutropils03

41、00.30300.3Neutropils6077311.535372.512.5Lymphocytes123014.820551.57Monocytes3100.21.51401.5Eosinopils2100.11.321201.5basopilsrarerarerareRareReference ranges for total and differential white blood cell counts2021/02/2426DogsCats percentageAbsolute vaTable 2 shows the alterations in some of parameter

42、s in various diseases.Laboratory assessmentTests to assess primary haemostasis include: Platelet count Bleeding time Clot retraction.Tests to assess secondary haemostasis include: Whole blood clotting time (WBCT) Activated clotting time (ACT) Activated partial thromboplastin time (APPT) One-stage pr

43、othrombin time (OSPT) Thrombin time (TT)DISORDERS OF WHITE CELL NUMBER2021/02/2427Table 2 shows the alterations Disseminated intravascular coagulation (DIC): This may be triggered by a wide variety of diseases, including endotoxaemia neoplasia (especially haemangiosarcoma 血管肉瘤) acute infections (e.g

44、. infectious canine hepatitis) haemolytic anaemia pancreatitis heat stroke. The clinicopathological features of DIC are: Thrombocytopenia Increased OSPT/APTT Elevated FDPs Low fibrinogen Schistocytes in the blood film. DISORDERS OF WHITE CELL NUMBER2021/02/2428Disseminated intravascular coa兽医临床病理学Co

45、llege of Veterinary Medicine, SCAU, Guangzhou,China 510642Veterinary Clinical Pathology2021/02/2429兽医临床病理学College of Veterinary MClinical biochemistryIntroduction Serum proteins Total protein and albumin Globulins Indicators of renal function Urea nitrogen Creatinine Markers of hepatic disease Alani

46、ne aminotransferase Aspartate aminotransferase Alkaline phosphatase Gamma-glutamyi transferase Bilirubin Bile acids Ammonia Pancreatic disease Amylase LipaseElectrolytes Sodium; Potassium; Chloride Magnesium; Calcium; Phosphorus Muscle enzymes Creatine kinaseAspartate aminotransferase Carbohydrate m

47、etabolism GlucoseFructosamine Lipid metabolism CholesterolTriglycerides Miscellaneous tests Iron Lead ZincCopper Chemical profiles and test selection 2021/02/2430Clinical biochemistryIntroductSERUM PROTEINSTotal protein and albumin Physiology The circulating proteins are synthesized predominantly in

48、 the liver, although plasma cells also contribute to their production. Quantitatively the single most important protein is albumin (35-50% of the total serum protein concentration). The other proteins are collectively known as globulins. The functions of proteins are many and varied but include main

49、tenance of plasma osmotic pressure, transport of substances around the body (e.g. ferritin铁蛋白, ceruloplasmin血浆铜蓝蛋白), humoral immunity, buffering and enzyme regulation. Indications for assay The measurement of proteins is generally included in an initial health screen in all patients but especially w

50、here intestinal, renal or hepatic disease or haemorrhage is suspected. Analysis Protein concentrations can be estimated in serum, plasma, urine or body fluids with a refractometer or by spectrophotometry. Serum albumin levels are measured by bromocresol green dye溴甲酚绿 binding and the serum globulin i

51、s calculated by subtraction of the albumin concentration from the total protein concentration. 2021/02/2431SERUM PROTEINSTotal protein anReference ranges Neonates and very young animals have lower concentrations of albumin and globulins (due to minimal quantities of immunoglobulins). As the animal g

52、ains immunocompetence the protein concentrations rise to reach adult values. Physiological decreases in albumin may be noted during pregnancy. Critical values Marked hypoalbuminaemia ( 1.030 in dogs, 1.035 in cats) supports the diagnosis of a prerenal azotaemia. INDICATORS OF RENAL FUNCTION2021/02/2

53、439Causes of increased blood ureaCreatininePhysiologyCreatinine is formed from creatine in the muscles in an irreversible reaction. The quantity of creatinine produced depends upon diet (small contribution) and the muscle mass. Disease affecting the muscle mass may affect the daily creatinine produc

54、tion. Both urea and creatinine are freely filtered at the renal glomerulus but urea is subject to tubular reabsorption and thus creatinine is said to be a better indicator of GFR.Analysis Creatinine can be measured in serum, plasma or abdominal fluid by spectrophotometric methods. Reference ranges D

55、ogs 20-110 umol/L Cats 40-150umol/L INDICATORS OF RENAL FUNCTION2021/02/2440CreatinineINDICATORS OF RENAL Causes of low serum creatinine Since the daily production of creatinine is dependent upon the muscle mass of the animal, the body condition should be considered when interpreting serum creatinin

56、e concentrations. A poor body condition may be associated with low concentrations while minor rises in such cases may be more significant than in other individuals. Causes of increased serum creatinine Decreased glomerular filtration is the major cause of raised serum creatinine. However, approximat

57、ely 75% of nephron function must be impaired before serum creatinine (and urea) is increased. Creatinine is considered a more reliable indicator of GFR than is urea nitrogen, since there are fewer factors which influence the serum concentration of creatinine. INDICATORS OF RENAL FUNCTION2021/02/2441

58、Causes of low serum creatinineThe biochemical parameters used to assess liver pathology may be divided into two classes: the hepatic enzymes that reflect liver damage and cholestasis, and the endogenous indicators of liver function. Alanine aminotransferase (ALT) is the most useful enzyme for identi

59、fying hepatocellular damage in dogs and cats but should not be used alone as a screening test for liver disease. The production of other enzymes, i.e. alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT), is increased secondary to intra- and extrahepatic cholestasis. These enzymes are mar

60、kers of cholestatic disease. Bilirubin, serum albumin and serum bile acids are considered to be indicators of hepatic function . It is common for extrahepatic disease (e.g. pancreatitis, diabetes mellitus, hyperadrenocorticism and inflammatory bowel disease) to cause abnormalities of these biochemic