appropriate laboratory investigation

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Laboratory interpretation

Lalita Norasetthada, MD Hematology Division,

Department of internal medicine, CMU

Laboratory interpretation

•Hematology lab

▫ CBC

▫ Coagulogram

•Blood chemistry

▫ Liver function

▫ Kidney function

▫ FPG and lipid profile

•Serologic test

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Normal Laboratory Values

2 SD

Abnormal Normal

normal values = mean ± 2SD of normal population

CBC : Complete Blood Count

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• ปริมาณลดลง ▫ การตดิเชือ้ไวรัส ▫ ยาบางชนิด ▫ โรคของไขกระดูกท าให้สร้างเม็ดเลือดขาวลดลง

• ปริมาณเพิ่มขึน้ ▫ การตอบสนองของร่างกายปกตทิี่เกิดในภาวะตดิเชือ้หรือการอักเสบ (< 30,000/uL)

▫ มะเร็งเม็ดเลือดขาว

• Normal range • 4,500-10,000 cell/mm3

• 4.5-10 x 103/uL

White blood cell count

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WBC morphology

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การตรวจ ค่าผลการตรวจ

ต ่า สูง

Hemoglobin Hematocrit

- ภาวะเสียเลือด -ขาดสารอาหาร เช่น ธาตุเหล็ก, ขาดวิตามิน

- ภาวะเม็ดเลือดแดงแตก จากการติดเชือ้, สารพิษ, ยา หรือดแตกเองในร่างกาย -ไขกระดูกผ่อหรือไม่ท างาน - มะเร็งของเม็ดเลือด

- ขาดสารน า้ -ภาวะที่มี OXYGEN ในเลือดต ่าเรือ้รัง เช่น สูบบุหร่ี - ไขกระดูกสร้างเม็ดเลือดสงูผิดปกติ

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RBC morphology

Concerning values

•For general dental procedure

▫ Hb > 7 gm/dl

•Procedure under GA

▫ Hb > 9.5-10 gm/dl

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การนับจ านวนเกร็ดเลือด (platelet count)

•Platelet count

▫ 100,000-450,000/mm3

▫ 100-450 x 103/uL

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การตรวจ ค่าผลการตรวจ

ต ่า สูง

เกร็ดเลือด

- ม้ามโต - เกร็ดเลือดถูกท าลายมากขึน้ จากยา, ภูมิต้านทาน - เกร็ดเลือดสร้างได้น้อยจากความผิดปกติของไขกระดูก • ไขกระดูกฝ่อ หรือ

ท างานผิดปกติ • ไขกระดูกถูกแทรกซึม

จากการติดเชือ้หรือมะเร็ง

• โรคมะเร็งเม็ดเลือด

-การอักเสบหรือการติดเชือ้เรือ้รัง -มะเร็งของอวัยวะอื่น -โรคไขกระดูกสร้างเม็ดเลือดเพิ่มมากผิดปกติ -มะเร็งเม็ดเลือดขาวเรือ้รัง

Platelet morphology

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Increased risk of bleeding when

• Platelet count

▫ <50,000/mm3 or < 50 x 103/uL

▫ > 1,000,000/mm3 or > 1,000 x 103/uL

• In mild thrombocytopenia, all dental

procedure can be done safely (50,000-

100,000/mm3)

Coagulation test

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Primary hemostasis

Secondary Hemostasis

In vivo

In vitro

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Coagulation test

• PT : prothrombin time

▫ Range 8-11 seccods

• aPTT : activated partial thromblastin

time ▫ Range 28-32 seconds

Isolated PT Prolongation

Inherited

• FVII deficiency

Acquired

• Vitamin K deficiency

• Liver disease

• Warfarin

administration

• Inhibitor of FVII

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Isolated PTT prolongation

Inherited

• Deficiency of F VIII, IX, XI

• Deficiency of FXII, prekallikrein, HMW kininogen

• VWD

Acquired

• Lupus anticoagulant

• Inhibitor to FVIII, IX, XI, XII

• Heparin administration

Combined PT and PTT prolongation

Inherited

• Deficiency of FV, X,

fibrinogen, prothrombin

Acquired

• Liver disease

• DIC

• Supratherapeutic dose of

warfarin and heparin

• Inhibitor of FV, X,

fibrinogen, prothrombin

• Primary amyloidosis

associated FX deficiency

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Bleeding risk

• Increased risk of bleeding after

invasive procedure when

▫ Either PT or aPTT increases > 1.5

folds above mid normal range

▫ Ex.

PT 24 secs (8-12), INR 2.5

PTT 40 secs (28-32)

Bleeding disorder in the setting

of normal screening test

• Platelet dysfunction

▫ Drug : aspirin, NSAID, clopidrogrel

▫ Chronic disease : liver/kidney failure

▫ Hereditary disorder

• Impaired fibrin crosslink and

fibrinolytic disorder

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Blood Chemistry BUN

Cr

Albumin / Globulin

GOT / GPT

Alk. Phosphatase

Cholesterol

Bilirubin

Cholesterol

Triglyceride

HDL

LDL

Plasma glucose

Kidney function

Liver function test

Lipid Profile

Kidney function test

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Laboratory test to evaluate kidney

function

• Glomerular filtration rate (GFR)

• Plasma creatinine

• Plasma urea

• Urine volume

• Urine electrolytes, protein, urea, osmolality

Glomerular filtration rate

• Value always adapted to the BSA!! Ideal BSA

in adults is 1.73m2

•Schwartz equation : GFR= v x 0.808

• Pcr

(umol/L)

•How to assess easy if plasma creatinine is OK

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Creatinine and Urea Plasma

Concentration- hyperbolic correlation

GFR 50%

pCr,

pUrea

140 mL/min

(100%) 0 mL/min

(0%)

Lower limit 90 ml/Min./1.73

m2 Normal

range->

Plasma urea (BUN)

• BUN (blood urea nitrogen) 10-20 mg/dl

• Urea: product of protein catabolism

• Synthesized by liver, excreted by kidney,

partially reabsorbed in tubuli

• Plasma concentration increases with

decreased GFR

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BUN in patients

with kidney diseases

• Useful test but must be interpreted with

great care ▫ urea plasma level is more than creatinine

dependent on protein intake

• Most useful when considered along

with creatinine ▫ High in high protein intake, UGI bleeding

▫ Low in severe liver dysfunction

Creatine Creatinine (Waste product)

H2O

• Creatine : main storage compound of high

energy phosphate needed for muscle

metabolism

• Creatinine: anhydride of creatine

• Creatinine is freely filtered by the glomerulii

and is not reabsorbed

Plasma creatinine and renal function

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• Plasma creatinine

Male 0.6-1.2 mg/dL,

Female 0.5-1.0 mg/dL

• Pre-renal disorder ▫ BUN:Cr ratio >20

• Renal and postrenal

disorders

▫ BUN: Cr 10-20 both

elevated

Analytic method

Filter

Processor

Input

Arterial

Output

Venous

Output

Urine

Liver function test

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Liver Function Test

Liver chemistry test Clinical implication of abnormality

ALT Hepatocellular damage

AST Hepatocellular damage

Bilirubin Cholestasis, impair conjugation, or biliary obstruction

ALP Cholestasis, infiltrative disease, or biliary obstruction

PT Synthetic function

Albumin Synthetic function

GGT Cholestasis or biliary obstruction

Bile acids Cholestasis or biliary obstruction

5`-nucleotidase Cholestasis or biliary obstruction

LDH Hepatocellular damage, not specific

Normal values

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Advantages

• Sensitive, noninvasive method of screening liver dysfunction

• Pattern of laboratory test abnormalities to recognize type of liver disorder

• Assess severity of liver dysfunction

• Follow cause of liver disease

Disadvantages

• Not specific for liver

dysfunction

• Seldom lead to specific

diagnosis

Liver Function Test

Liver function test

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Classified in 3 groups

•Synthetic function : albumin,

prothrombin time (PT)

•Hepatocyte injury : AST, ALT

•Cholestasis : bilirubin, ALP, GGT

PT, albumin, bilirubin : most common tests used as prognostic factors

Liver Function Test

Liver function test

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Albumin

•Depending on nutrition, volume status, vascular integrity, catabolism, hormone, loss in stool and urine •Not specific for liver disease •T1/2 19-21 D

Globulin

• Produced by stimulated B-lymphocyte

• Elevation in

• chronic liver disease

• chronic inflammation and malignant

disease

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Hypoalbuminemia

globulin chol/TG Hb

1.decrease synthesis

-protein malnutrition

-chronic liver disease

-chronic inflammation

2.increase loss

-Protein loosing enteropathy

-NS

3.increase Vd (ascites, overhydration)

Metabolic Syndrome

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Abnormal Lipid

Metabolism

LDL

ApoB

HDL

Trigly.

Cardiometabolic Risk Global Diabetes / CVD Risk

Overweight / Obesity

Inflammation

Hypercoagulation

Hypertension

Smoking

Physical Inactivity

Unhealthy Eating

Age, Race,

Gender,

Family History

Glucose BP Lipids

Age Genetics

Insulin Resistance

Insulin Resistance

Syndrome

Cardiometabolic Risk - Graphic

Interpreting Blood

Glucose Levels

• Fasting glucose : No caloric intake > 8 hours ▫ Healthy BG FPG < 100 mg/dL

▫ Pre-diabetes FPG 100–125 mg/dL

(Impaired fasting glucose)

▫ Diabetes FPG ≥126 mg/dL

• Random plasma glucose ▫ PG > 200 mg/dl

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Total Cholesterol Goals34

• Desirable — Less than 200 mg/dL

• Borderline high risk — 200–239 mg/dL

• High risk — 240 mg/dL and over

American Diabetes Association. Understanding Cardiometabolic Risk: Broadening Risk Assessment and Management,

Dyslipidemia Richard M Bergenstal, MD International Diabetes Center

Lipid profile

•No caloric intake > 12 H

•Lipid profle

▫ Total choleterol

▫ LDL

▫ HDL

▫ TG

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Cholesterol Management

Category of risk LDL-C Goal

0-1 risk factor* < 160 mg/dL or lower

Multiple (2+) risk factors* < 130 mg/dL or lower

People with coronary heart

disease or risk equivalent

(e.g., diabetes)

< 100 mg/dL or lower

Known CAD and DM < 70 mg/dL or lower may be ideal

LDL-C-lowering

Serologic tests

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Test and window period

Virus marker window period

mean range

HBV HBsAg 59 37-87

HCV anti-HCV 82 54-192

HIV anti-HIV-1/2 22 6-38

HTLV anti-HTLV-I 51 36-72

NAT yield in Thailand : The National Blood Centre Thai Red Cross

Society

HIV 1:97,000

HCV 1:490,000, HBV 1:2,800

Viral hepatits

•Acute

▫ AntiHAV

▫ HBsAg

•Chronic

▫ HBsAg

▫ AntiHCV

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Main Ways to Get Hepatitis A

Fecal-oral route

Viral hepatitis A

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Having sex without condoms with

someone who has hepatitis B

Main Ways to Get Hepatitis B

Sharing needles and syringes

Being born to a mother who has

hepatitis B

Receiving blood component from

HBV infected donor

Natural history of HBV - related infection

Acute

hepatitis Contamination

Resolution Chronic infection

95%

Chronic hepatitis

5%

Inactive carriage

HCC Cirrhosis

3-5% yearly

Asymptomatic 30%

Fulminant hepatitis 1%

66% 33%

10-20%

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Viral hepatitis B

If you have never had hepatitis B,

you can get 3 shots . . .

. . . and get long lasting

protection.

3 2 1

Hepatitis B can be prevented!

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Main Ways to Get Hepatitis C



HCV infected donor

Hepatitis C Virus (HCV)

•HCV Infection

- Acute infection

- Mild symptoms

- 50-70% of affected patients develop

chronic hepatitis

- 20% of affected patients develop

cirrhosis or hepatocellular carcinoma

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Viral hepatitis C

HIV infection

•AIDs situation in Thailand, March

2011

•Prevalence 0.6% ▫ Total HIV infected cases 372,874 persons

▫ Already died 98,153 persons

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Having sex without condoms with HIV

infected persons

Main Ways to HIV


Being born to a mother who has

HIV


HBV infected donor

Strauss JM & Strauss EG,2002

HIV

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Who to Test for HIV

• High risk groups include ▫ MSM

▫ Injection drug users or history injection drugs

▫ Heterosexual partners of those listed above

▫ Those interested in HIV testing

▫ People presenting with an opportunistic infection or recurrent/severe infections that can not otherwise be explained

HIV Testing

• EIA- standard serologic screening test ▫ Needs to be repeatedly positive

▫ Should not give the patient this test result until

confirmed

• Western Blot-confirmatory test. ▫ 2 bands of the following: p24, gp41 or gp120/160

Antibodies to p24 and p55 appear earliest but decrease or

become undetectable.

Antibodies to gp31, gp41, gp120, and gp160 appear later but are

present throughout all stages of the disease

▫ EIA and Western Blot >99.9% sensitive and

specific

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Window period in HIV infection

HIV Testing

• 4-20% of test results are indeterminate with WB assays with positive bands for HIV-1 proteins

• Causes of indeterminate tests include ▫ Patients in the process of

seroconversion ▫ HIV-2 infection ▫ Cross-reacting nonspecific antibodies ▫ Testing should be repeated at 6-8 weeks,

3, and 6 months

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HIV Testing

•Rapid testing ▫ Two tests FDA approved, SUDS and

Oraquick

▫ Oraquick much easier and very accurate

▫ Sensitivity and Specificity is 99.5%

▫ Positives still need confirmation ▫ Similar to performing a pregnancy

test

The End

appropriate laboratory investigation

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