Nur Aisyah AzizPathology Practical 15.12.2010

BASICComposition of Blood5L (1/13 of body weight): 3L plasma + 2L cells

Plasma: intestine & lymphatic systemBlood cells: RBCs (erythrocytes), WBCs (leucocytes) & platelets (thrombocytes)

Hematopoeisis: Liver (before birth) Spleen & lymph nodes (minor role – midfetal life) BM (after birth)

Blood testBasic screening for disorders of Hb and cell production, synthesis & functions

Specimen collection: Capillary skin punctures (finger, toe, heel)Dried blood samplesArterial or venous samplingBM aspiration

Specimen Collection Procedures1.Capillary puncture (skin puncture) Preferred for peripheral blood smear Clinical alert: Do not squeeze the site to obtain blood – alters blood compositions &

invalidates test values Warming extremities or placing it in a dependent position – may

facilitate specimen collection

2. Venipuncture Allows procurement of larger quantities of blood Vein of choice: antecubital vein Blood values remain constant – regardless of venipuncture site, not

arterial blood Venipuncture errors: Pretest, Procedure & Posttest

Specimen Collection Procedures

Preventions for venipuncture errors:

3. BM aspirationBM is located within cancellous bone &

bone marrow cavitiesBM consists of pattern of vessels and

nerves, differentiated hemopeitic cells, RE

cells & fatty tissuesImportant to evaluate a number of

hematologic disorders & infectious ds.Presence of suspicious of a blood disorder

not always an indication for BM studies

decision on individual basisBefore BM procedure: blood smear

should be obtained from pts & diff.

leukocyte count done

Specimen Collection Procedures

3. BM aspiration: Clinical Implications①Clues for many ds. – presence, absence, ratio of

cells

②Abnormal cell patterns:

Multiple myeloma, plasma cell myeloma,

macroglobulinemia

Chronic or Acute leukemias

Anemia (megaloblastic, macrocytic & normocytic)

Toxic states that cause BM depression &

destruction

Neoplastic ds. – BM invaded by tumour cells

Agranulocytosis – white cell production

③Platelet dysfunction

④Infectious ds – histoplasmosis & tubercuklosis

⑤Def. of body iron stores, microcytic anemia

⑥Lipid or glycogen storage ds.

Normal

Hypoplastic

Hyperplastic

Bone Marrow

Basic blood tests: Complete blood count (CBC)Basic screening test – most frequent ordered laboratory proceduresValuable diagnostic test: hematologic and other body systems, prognosis, response to treatment and recoveryConsist of series of tests – no., variety, percentage, concentrations & quality of blood cells:1)White blood cell count (WBC): leukocytes fight infection2)Diff. white blood cell count (Diff.): specific pattern of WBC3)Red blood cell count (RBC):4)Hematocrit (Hct): measures of RBC mass5)Hemoglobin (Hb): main component of RBCs and transport O2 and CO2

6)RBC indices: calculated values of size and Hb content of RBCs – important in anemia evaluations7)Mean corpuscular volume (MCV)8)Mean corpuscular hemoglobin concentration (MCHC)9)Mean corpuscular hemoglobin (MCH)10)Stained red cell examination (film or peripheral blood smear)11)Platelet count (often included in CBC)12)Red cell distribution width (RDW): degree of variability and abN cell size13)Mean platelet volume (MPV): index of platelet production

Adult Reference Ranges for Red Blood Cells

Measurement (units) Men WomenHemoglobin (gm/dL) 13.6–17.2 12.0–15.0

Hematocrit (%) 39–49 33–43

Red cell count (106 /µL) 4.3–5.9 3.5–5.0

Reticulocyte count (%) 0.5–1.5

Mean cell volume (µm3 ) 82–96

Mean corpuscular hemoglobin (pg) 27–33

Mean corpuscular hemoglobin concentration (gm/dL)

33–37

RBC distribution width 11.5–14.5

1.White blood cell count (WBC; Leukocyte count)

Leukocytosis vs Leukopenia

??? Clinical Implications

Leukocytosis Leukopenia1. Increase of only one type of leukocyte

1. Rarely caused by a proportional increase in leukocytes of all types

2. Of a temporary nature (leukemoid reaction) must be distinguish from leukemia

3. In leukemia: permanent & progressive4. Acute infection: depends on severity of

infection, pts resistence, age and marrow efficiency & reserve

5. Other causes: Leukemia, Myeloproliferative disorder, Trauma, Tissues injury, Malignant Neoplasm, Toxins, Drugs, Acute hemolysis, Hemorrhage, After splenectomy, Polycythemia vera & Tissue necrosis

6. No eveidence of clinical ds.: Physiologic leukocytosis (excitemnt, stress, exercise, pain, cold or heat, anesthesia), Sunlight, UV irradiation, Nausea, Seizures & Vomitting.

1. Viral & bacterial infection

2. Hypersplenism

3. Bone marrow depression caused by heavy-metal intoxication, ionizing radiation, drugs

4. Primary BM disorder: Leukemia, Aplastic anemia, Pernicious anemia, Myelodisplastic syndromes, congenital disorder etc.

5. Immune-associated nuetropenia

6. Marrow-occupying ds (fungal infection, metastatic tumour)

7. Pernicious anemia.

2. Diff. white blood cell count (Diff; Differential Leukocyte Count)

• Total count of circulating WBC, differentiated according to 5 types of leukocytes – each with specific fx.

• Percentage of the total number of leukocytes (WBC)

• The distribution (number & types) of cells and the degree of increase or decrease are dx significant.

Neutrophils Pyogenic infections (bacterial)

Eosinophils Allergic disorders & parasitic infections

Basophils Parasitic infection, some allergic disorder

Lymphocytes Viral infections (measles, rubella, chicken pox)

Monocytes Severe infections, by phagocytosis

3. Red cell count• Important in evaluation of anemia or polycythemia

• Determines the total number of erythrocytes in a microliter of blood

• Clinical Implications:

RBC values vs. Erythrocytosis

RBC values Erythrocytosis

1. Anemia

2. Hodgkin’s ds & other

lymphoma

3. Multiple myeloma

4. Leukemia

5. Myeloproliferative disorder

6. Acute & chronic hemorrhage

7. Lupus erythematous

8. Addison’s ds

9. Rheumatic fever

10.Subacute endocarditis

11.Chronic infection

1. Primary erythrocytosis (PV,

erythemic erythrocytosis)

2. Secondary erythrocytosis

(Renal ds, extrarenal

tumours, High altitude,

pulmonary ds, cardiovascular

ds, alveolar hypoventilation,

Hemoglobinopathy, tobacco,

carboxyhemoglobin

3. Relative erythrocytosis (dec.

in plasma volume):

dehydration – vomiting &

diarhea

4. Hematocrit (Hct); Packed cell volume (PCV)

Important measurement for anemia & polycythemia

Hematocrit – ‘to separate blood’ Test mechanism: plasma & cells are

separated by centrifugation Measures the RBC mass Percentage of volume of packed RBCs in

whole blood (PCV)

Clinical implications: Hct vs Hct = ?????????

Hct Hct

1. Anemia

2. Leukemias

3. Lymphomas

4. Hodgkin’s ds

5. Adrenal insufficiency

6. Chronic ds.

7. Acute & Chronic blood loss

8. Hemolytic reaction: transfusion

of incompatible blood, reactions

to chemicals or drug, infectious

agents or physical agents such

as severe burns, prosthetic

heart valves.

1. Erythrocytosis

2. Polycythemia vera

3. Shock – when

hemoconcentration rises

considerably.

HOWEVER….

•Hct may or may not be reliable immediately after even a moderate loss of blood or after transfusion

•Hct may be N after acute hemorrhage

•Hct is parallels the RBC when the cells are of N size Pts with microcytic or macrocytic anemia – NOT TRUE

Iron def. anemia with small RBCs Hct decreased …due to microcytic cells pack to a smaller volume

5. Hemoglobin; Hb Main component of erythrocytes Vehicle for O2 and CO2 transportation The O2-combining capacity is directly proportional to

[Hb]

Hb determination is important Evaluation of anemia Determine severity of anemia Treatment response monitoring Evaluation of polycythemia

Clinical implications: DECREASED vs INCREASED

Hb Hb1. Anemia states (Hb must be

evaluated along with Hct and RBC; Iron-def., thalassemia, pernicious anemia, hemoglobinopathies, liver ds., hypothyrodism, hemorrhage-chronic & acute, Hemolytic anemia)

1. Polycythemia vera2. Congestive heart failure3. COPD

Variation in Hb level:•Occurs after transfusions•Hemorrhage•Burns

Hb and Hct provide valuable information in an emergency situation if they are interpreted not in an isolated fashion but in conjunction with other pertinent laboratory data

RBC, Hct, and/or Hb

Relative polycythemia: Hb-Hct or RBC caused by plasma volume Dehydration

Absolute or True polycythemia:Primary (PV, erythemic erythrocytosis)Secondary: Appropriate vs Inappropriate

Appropriate: Physiologic conditions – altitude, cardiopulmonary disorder. Increased affinity to O2

Inappropriate: Renal tumor or cyst, Hepatoma, Cerebral hemangioblastoma

Clinical implications of POLYCYTHEMIA:

RBC, Hct, and/or Hb

Pathophysiology states:

Examples:

Hypoproliferative anemia Marrow aplasia, Myelopthisic anemia, Anemia of chronic ds, etc

Maturation defect anemias

Cytoplasmic – hypochromic anemiasNuclear – Megaloblastic anemiaCombined: Myelodisplastic syndromes

Hyperproliferative anemias

Hemorrhagic – Acute blood lossHemolytic – a premature, accelerated destruction of RBCs

Dilutional anemias PregnancySplenomegaly

Clinical implications of ANEMIA:

RBC indices Define the size & Hb content of the RBC Consist of MCV, MCHC and MCH

To differentiate anemias:

by cell size: Macrocytic, Microcytic & Normocytic

by colour: Hypochromia, Hyperchromia, Anisochromasia, Polychromasia

Microcytic red cells (MCV 62fl)

Normocytic red cells

Macrocytic red cells (MCV 105 fl)

Hyperchromic cells (MCHC)

Normochromic cells (N MCHC)

Hypochromic cells (MCHC)

Mean Corpuscular Volume (MCV) – index of single erythrocyte volume (fL)MCV (fL) = Hct (%) X

10 RBC (1012/L)

Mean Corpuscular Hemoglobin Concentration (MCHC) – average [Hb] in RBCs

MCHC (g/dL) = Hb (g/dL) X 100 Hct (%)

Mean Corpuscular Hemoglobin (MCH) – average Hb weight per RBC MCH (pg/cell) = Hb (g/dL)

X 10 RBC (1012/L)

Red Cell Size Distribution Width (RDW) – indication of the degree of anisocytosis

RDW (CV%) = Standard deviation of RBC size X 100

MCV

Sedimentation Rate (Sed Rate); Erythrocyte Sedimentation Rate (ESR)

The rate for which erythrocytes settle out of anticoagulated blood in 1 hour

Sedimentation – occurs when the erythrocytes clump or aggregate together in a column-like manner (ROULEAUX FORMATION)

Changes are related to alterations in plasma proteins

N state: erythrocytes settle slowly – N RBCs do not form rouleaux

• The test is based on the fact that inflammatory and necrotic processes cause an alteration in blood proteins, resulting in aggregation of RBCs, which makes them heavier and more likely to fall rapidly when placed in a special vertical test tube.

• The faster the settling of cells, the higher the ESR

• ESR is used in diagnosis of temporal arthritis, rheumatoid arthritis and polymyalgia rheumathica, also useful in monitoring the progression of inflammatory ds.

ESR

1 = Normal ESR2 = Normal ESR with reddish plasma in hemolysis (disease or artifact)3 = Blurring of the plasma-erythrocyte border in reticulocytosis4 = White turbidity and blurring in severe leukocytosis of leukemia5 = Accelerated ESR and lipemic plasma after a fatty meal6 = Accelerated ESR and icteric plasma7 = "Zero" ESR in polycythemia8 = Severely accelerated ESR in multiple myeloma

Normal ESR ESR

1. PV, eryhthrocytosis

2. SC anemia, Hb C ds.

3. Congestive heart failure

4. Hypofibrinogenemia

5. PK def.

6. Hereditary spherocytosis

7. Anemia – N ESR in iron-def. ;

abN ESR in anemia of chronic ds

alone or in combination with

iron-def.

Etc.

1. All collagen ds. (SLE)

2. Infections, pneumonia, syphilis,

TB

3. Inflammatory ds. (acute pelvic

inf. Ds)

4. Carcinoma, Neoplasms,

Lymphoma

5. Acute-heavy metal posioning

6. Cell or tissue destruction, MI

7. Toxemia, pregnancy

8. Nephritis, Nephrosis

9. Anemia – acute or chronic ds.

10.Rheumatoid arthritis

Etc.