Laboratory Diagnosis

What is laboratory diagnosis?

Laboratory diagnosis is such a diagnostic process in which the samples coming from patients’ blood , body fluid , secretion , excretion , tissues and cells are examined by using various laboratory methods to get useful data which may reflects body` s functional status , pathological changes and etiological hints.

Why to study laboratory diagnosis?

Laboratory diagnosis is a very important part in diagnostics. After we have finished the study of physical diagnosis and instrument examination , we might be able to judge what kind of disease this patient probably suffer from . For further diagnosis , it is still not enough if we only master physical examination . We have to depend upon some laboratory data to ensure our diagnosis .

How to learn laboratory diagnosis?

First, the methods used in laboratory diagnosis are more automatic and computerized.

Second , the aim is to train for clinical application .

For each test, referential values and clinical significance always should be known very well.

Chapter 1 Blood Test Blood routine test (BRT)

1. content (items) of BRT red blood cell count (RBC) hemoglobin(HB)concentration determination total white blood cell count (WBC) leukocyte differential count (DC) platelet count (PC)

1. content (items) of BRT red blood cell count (RBC) hemoglobin(HB)concentration determination total white blood cell count (WBC) leukocyte differential count (DC) platelet count (PC)

Rferential values of BRT Table 1. Deferential values for blood routine test in different age

and sex ___________________________________ male female newborn

___________________________________

RBC 4.0-5.5 3.5-5.0 6.0-7.0 HB 120-160 110-150 170-200 WBC 4-10 4-10 15-20 PLT 100-300 100-300 ___________________________________

Table 2 Referential values of differential count

___________________________________ type percent value(%) absolute value ___________________________________ N st 1-5 0.04-0.5 N se 50-70 2-7 LYM 20-40 0.8-4 Mo 3-8 0.12-0.8 Eo 0.5-5 0.02-0.5 Ba 0-1 0-0.1 ___________________________________

Morphology of blood cells

Red blood cell: normocyte: 6-9um, discocyte- shape, no nucleus

white blood cell divided in five types: neutrophilic granulocyte : neutrophil stab cell (Nst), neutrophil segmented cell (Nse), lymphocyte, basophil granulocyte, eosinophil granulocyte

Platelet: smallest cell in peripheral blood

In automatic blood cell analyzer,25 items are included together : WBC : 4.0~10.0x109/L LYM : 0.8~ 4.0 x109 /L (20~40%) MID( middle cells) : monocyte, eosinocyte, basoc

yte , immature cells(rare be seen) GRAN(granulocyte):2.0~7.8x109/L(50~70%) RBC:4.0~5.5x1012/L(male),3.5~5.0x 1012 /L (fe

male) HGB: 120~160 g/L (male), 110~150 g /L (femal)

--

HCT(hematocrit):0.4~0.5L/L(male), 0.37~ 0.48 L/L (female)

MCV ( mean corpuscular volume): 82~95 fl MCH(mean corpuscular hemoglubin): 27~31 pg MCHC ( mean corpuscular hemoglubin concentration)

: 320~360 g/L RDW ( red cell distribution width ): 11.5~14.5% PLT( platelet): 100~300x109 /L MPV ( mean platelet volume): 8.7~16.5 fl PDW ( platelet distribution width): 15.8~21.4%

Clinical significance

Anomalies of RBC and HB 1. decrease of RBC and HB Anemia: When RBC and HB of individual i

s lower than the referential values of the people in same age , same sex and same area. Usually, if Hb of adult male and female is lower than 120g/L or 110g/L respectively, they are considered as anemia.

According to the level of Hb, anemia is divided into four degrees i

n clinic

mild anemia: Hb < 120g/L(male) or < 110g/L(female)

medium anemia : Hb <90 g/L severe anemia : Hb <60g/L extreme severe anemia: Hb <30g/L

Physiological anemia

infant and children aged between 3 months to 15 years,

pregnant women in middle or terminal periods of pregnancy,

elderly people.

Pathological anemia.

decrease in synthesis of red blood cell in bone marrow

increased destroy of red blood cell in peripheral blood

blood loss

Decrease in synthesis of red blood cell in bone marrow

disorder of hemopoiesis in bone marrow: aplastic anemia

infiltration of bone marrow by tumorous cell: leukemia, multiple myeloma , lymphoma , metastatic tumor

deficiency of hemopoietic materials or factors: iron deficiency anemia(IDA), megaloblastic anemia (folic acid deficiency)

Destroy of RBC in peripheral blood -- hemolytic anemia

Hereditory disease : hereditory sphrocytosis (HS) , G6PD deficiency, thalassmia , Hb disease

Acquired anomalies : hemolysis by immunological , physical, chemical , biological and mechanical factors

Blood loss -- hemorrhagic anemia

acute blood loss : acute upper digestive tract bleeding , splenic rupture

chronic blood loss : hemorrhoid, hookworm disease, hypermenorrhea, GI tumor

2. Increase of RBC and Hb

• Comparative increase of RBC and Hb: due to the decrease of volume of plasma--severe dehydration: severe vomoting, diarrhea, severe burn

• Absolute increase of RBC and Hb—ery-throcytosis: polycythemia vera(PV), chronic cardiopulmonary diseases: cor pulmonale, obstructive emphysema, scarcity of oxygen.

Anomalies of WBC and DC

•In most cases, increase and decrease of WBC is chiefly depend on the numbers of neutrophil granuiocyte in the blood.

•Leukocytosis: WBC is high than 10 x109 /L

•Leukopenia: WBC is lower than 4 x109 /L

1. Neutrophil granulocyte

A. granulocytosis: 5 causes leading to granulocytosis

• acute infection or inflammation: acute pyogenic

tonsilitis, acute appendicitis, hematosepsis

• damage or necrosis of tissue: severe burn, acute myocardiac infarction

•acute blood loss: digestive tract bleeding,

splenic rupture

•Acute poisoning: uremia, ketoacidosis

•Malignant blood diseases and tumor:

leukemia, metastatic tumor

B. Granulocytopenia:

• leukopenia: WBC < 4 x109 /L

• granulocytopenia:

neutrophil granulocyte < 1.5 x109 /L

• agranulocytopenia:

neutrophil granulocyte < 0.5 x109 /L

5 causes for granulocytopenia:

• Infection of bacteria and virus: typhoid, influenza,

measles

• some physical and chemical factors: drug

• autoimmune diseases: systemic lupus erythematosis (SLE),

• malignant blood diseases: aplastic anemia,leukemia

•hypersplenism

Changes of nucleus

nucleus shift to left:

• mild shift to left: Nst > 6% only

• medium shift to left: Nst > 10% with meta-

myelocyte

• severe shift to left : Nst > 25% with more

immuture cell (leukemiod reaction )

nucleus shift to left cab be seen in acute infection,

acute poisoning, acute hemolysis

Nucleus shift to right: multi-segmented Nse >3%

3-lobed Nse is normal segmented neutrophil in BP

nucleus shift to right can be seen

• megaloblastic anemia

• administration of anti-metabolic drugs

2. lymphocyte

A . Lymphocytosis: DC: Lym > 40%

•Virus infection: infectious mononucleosis,

chickenpox,

•Lymphocytic leukemia: ALL, AA, lymphoma

•GVHD or GVHR after BMT

B. lymphocytopenia:

•administration of anti-tumor drugs, prednision

•radiation: x-ray, r-ray , isotope

3. monocytosis:

• malaria, black fever, TB, subacute bacterial

endocarditis(SBE)

• monocytic leukemia, malignant histocytosis,

4. eosinophilia

•allergic diseases, hypersensitive diseases

•parasites infection:

•Skin diseases: psoriasis

•blood diseases: CML, eosinophilic leukemia,

lymphoma

•Infectious diseas: scarlatina

•Hypereosinophilic syndrome

5. Basophil granulocyte

bosophilia: CML, basophilic leukemia,

myelofibrosis

Other tests for red blood cellOther tests for red blood cell

1. Reticulocyte count (RC)

0.05-0.015 (0.5-1.5%)

24-84 x109 /L

Reticulocytosis: hemolytic anemia

acute hemorrhagic anemia

index of therapeutic effect:

IDA, megaloblastic anemia

•Reticulocytopenia:

Aplastic anemia

leukemia

2. Hematocrit(Hct)

0.4-0.5L/L(male), 0.37-0.48L/L(female)

• increase of Hct:

blood concentration

water loss

polycythemia(PV)

• decreas of Hct: anemia

3. Mean values of RBC

Mean corpuscular volume (MCV):

MCV=Hct/RBC 82-95fl

Mean corpuscular hemoglubin(MCH):

MCH=Hb/RBC 27-31pg

Mean corpuscular hemoglubin concentration

MCHC=Hb/Hct 320-360g/L

Morphological classification of anemia

Classification MCV MCH MCHC diseases

Normocytic 82-95 27-31 320-360 AA, HA, leukemia

Macrocytic >100 > 31 320-360 MA, pernicious

anemia

Microcytic < 80 < 27 320-260 infection, tumor,

uremia

Microcytic < 80 < 27 < 320 IDA, thalassemia

Hypochromic sideroblastic

anemia

4. Erythrocyte sedimentation rate(ESR)

0-15mm/h (male), 0-20mm/h (female)

higher ESR:

• infection and inflammation: rheumatic diseases,tuberculosis

• malignant tumor

• anemia

• damage or necrosis of tissue

• globulinemia, cholesterolemia

Chapter 2. Bone MarrowChapter 2. Bone MarrowExaminationExamination

1. Clinical application of marrow examination Diagnosis for hematopoietic system diseases:

leukemia, myeloma, aplastic anemia, etc parasite infectious diseases: malaria, black

fever metabolic diseases: Gaucher disease. Nieman

n-Pick disease

Indications:

•Fever origin unknown (FOU)

•Cachexia

•Hepatomegaly, splenomegaly, lymphoadenovarix

•Abnormal in quantity and quality in peripheral

blood cell

Contraindication:

• Hemophilia

• Pyogenic infection in local skin

Methods:

• bone marrow aspiration

• bone marrow biopsy

2. Development of blood cells

myeloblast promyelocyte myelocyte metamyelocyte Nst Seg

normoblast basophilic normoblast

polychromatic normoblast orthochromatic

normoblast erythrocyte

Monoblast promonocyte monocyte

macrophage histiocyte

Megakaryoblast promega granular Meg

thrombocytogenous Meg platelet

B-lymphoblast B-prolymphoblast B-lymphocyte plasmablast proplasmacyte

plasmacyte

3. Regulation of blood cell 3. Regulation of blood cell developmentdevelopment

Cytobody: from large to small,

Mega is an exception Cytoplasma: from less to more,

color from blue to pink or orange red,

granules from invisible to visible,

granules from non-specific to specific

Nucleus: from large to small, Mega is an exception, shape of nucleus from round to irregular, chromatin patten of nucleus from fine to coarse. nucleolus from existance to nonexistanceRation of nucleus to cytoplasma: from bigger to smaller

5.Contene and step of marrow 5.Contene and step of marrow examinationexamination

Myelogram: Low power(LP):

Wright stain of marrow film

plastic degree: 5 classification

Meg count : 7-35/1.5x3cm2

ousspecial cell: metastatic tumorous cell

•Oil immersion:

Nucleated cell count (%): 200-500

Ratio of myeloid to erythroid (M:E): 2-4:1

Morpholigical description of every series

Special cells and parasite

•Diagnosis

•Hemogram:

Low power(LP):

Oil immersion len: differential count 100

leukocyte (DC)

Immature cell (nucleated cell)

parasites

6. Normal myelogram and he6. Normal myelogram and hemogrammogram

1. Myelogram Normal cellularity: erythrocyte: nucleated cell M:E=2-4:1 Granulocytic series is 40-60% in all nucleated cells Erythrocytic series is 20% in all nucleated cells Lymphocyte is 20% , monocyte is <4% in all nucleated cells Meg count is 7-35, platelet is normal Other cell: plasmacyte and histiocyte are rare No specific cells and parasite

Plastic degree of marrow

Plastic degree erythrocyte: nucleated diseases

Extreme hypercellularity 1:1 leukemia

Significant hyper- 10:1 leukemia, ITP,

Cellularity plastic anemia

Normal cellularity 20:1 anemia, normal

myelogram

Hypocellularity 50:1 AA,agranulocy-

topenia

Extreme hypocellularity 300:1 aplastic anemia

2. Hemogram:

•DC is normal

•No nucleated red blood cell

•No immature white cell

•Platelet is normal

7. Characters of common bloo7. Characters of common blood diseases in microscoped diseases in microscope

Iron deficiency anemia(IDA) Aplastic anemia(AA) Acute leukemia(AL) Chronic myelocytic leukemia(CML) Idiopathic thrombocytopenia purpura(ITP)

1. Iron Deficiency Anemia(IDA) 1. Iron Deficiency Anemia(IDA)

Hemogram:

Hb , RBC , normal RC,

RBC hypochromia, exaggeration of central pallor to from rings, anisocytosis

normal WBC and platelet

•Myelogram:

Significant hypercellularity

M:E

Erythroid hyperplasia with small normoblast

Pycnotic nuclei and scanty cytoplasma

irregular margin

2. Aplastic Anemia(AA)2. Aplastic Anemia(AA)

Hemogram:

pancytopenia: Hb ,RBC , WBC ,PLT

RC <0.005 or absolute value < 15 x109 /L

RBC is normocytic

•Myelogram:

Hypocellularity or extreme hypocellularity,

Hematopoietic cell decrease: erythroid, myeloid

cells , meg or absent, platelet rarely be seen

Non-hematoietic cell increase: lymphocyte

Reticular cell , plasmacyte

3. Acute Leukemia(AL)3. Acute Leukemia(AL)

FAB classification:

acute lymphocytic leukemia: L1-L3

acute non-lymphocytic leukemia: M0-M7 Hemogram:

Hb, RBC

WBC uncertain: normal, increase, decreas

platelet:

•Myelogram:

Extreme or significant hypercellularity

M:E

Hyperplasia of certain line :

Myeliod(M0,M1-3), monocyte(M4-5), meg(M7), lymphocyte(L1-3) , erythroid(M6)

Depressed erythroid and meg line

4. Chronic Myelocytic Leuke4. Chronic Myelocytic Leukemia(CML)mia(CML)

Hemogram:

WBC increase rxtremly

DC: E0, Ba increas, myelocyte,

metamyelocyte, band cell increase

normal Hb, RBC or mild decrease

normal plt

•Myelogram:

Extreme hypercellularity

M:E increase

Extreme hyperplasia of granulocyte with increas of myelocyte, metamyelocyte, band cell, E0, Ba

Normal erythroid and Megakaryocyte

5. Idiopathic Thrombocytopenic P5. Idiopathic Thrombocytopenic Purpura(ITP)urpura(ITP)

Hemogram:

normal Hb, RBC

normal WBC and DC

PC decreas with abnormal morphology

•Myelogram:

Significant hypercellulerity or normal cellularity

Normal myeloid, erythroid line

Significant hyperplasia of Meg.

Impaired maturation of Meg:

Granular Meg or promeg increase

Platelet producting Meg absent

Platelet rarely be seen