Leiny García Rev. Lasallista Investig. vol.7 no.2 Caldas. 2010.
Lab investig
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Transcript of Lab investig
Dr. Iman M. Fawzy; MD. PhD.Mansoura, Egypt
BASIC LABORATORY INVESTIGATIONS
Urinalysis
COMPONENTS OF THE URINE DIPSTICK
• Color:pale yellow to amber• Specific gravity: 1.015–1.025• pH: 4.5–8.0• Protein: negative• Glucose: negative• Ketone: negative• Bilirubin: negative• Urobilinogen: 0.2–1.0• Blood: negative• Nitrite: negative• Leukocytes (esterase): negative
COMPONENTS OF THE URINE DIPSTICK
Microscopic Examination of Urine Sediment
Increased WBCs are seen in Urinary tract disease (eg, cystitis, prostatitis)Chronic pyelonephritisTuberculosisViral infectionInterstitial nephritisGlomerulonephritis
WBC casts Pyelonephritis (most common cause)Acute glomerulonephritisInterstitial nephritisLupus nephritis
URINE WHITE BLOOD CELLSNormal Values: WBCs: 0–4/hpf
Microscopic Examination of Urine Sediment
Increased numbers of RBCs occur in • Contamination during Menstrual cycle • Glomeulo and Pyelonephritis• Renal stones• Cystitis (acute or chronic)• Prostatitis• Genitourinary tract malignancies• Bleeding disorders• Trauma• Anticoagulant therapy overdose
RBC casts in• Glomerulonephritis (acute and chronic)• Renal infarction• Severe pyelonephritis• Congestive heart failure• Renal vein thrombosis
URINE RED BLOOD CELLSNormal Values: RBCs: 0–3/HPF
Microscopic Examination of Urine SedimentGRANULAR CASTSAcute tubular necrosis Advanced glomerulonephritis Pyelonephritis Malignant nephrosclerosisFever (dehydration)
Hyaline castsGlomerulonephritis, pyelonephritis Malignant hypertension Chronic renal disease Diabetic nephropathyFever (dehydration) Emotional stress Strenuous exercise
WAXY CASTSChronic renal disease Nephrotic syndrome Localized nephron obstruction
Fatty castslipiduria e.g. nephrotic syndrome
Urinary sediment crystals
Acidic urine• Uric acid crystal• Amorphous urates• Cholesterol crystals
Alkaline urine• Triple phosphate
crystals• Calcium phosphate• Amorphous phosphates
ACID, NEUTRAL, OR SLIGHTLY ALKALINE URINECalcium oxalate
URINE COMPOSITION URINALYSIS: FINDINGS IN COMMON DISEASE STATES.
Disease Protein RBC WBC Casts Other Microscopic Findings
Normal 0 0 or Occ 0 or Occ 0 or Occ Hyaline casts
Fever Trace or 1+ 0 Occ 0 or Occ Granular, Hyaline casts
Eclampsia 3+-4+ 0 or 1+ 0 3+, 4+ Hyaline castsDM v 0 0 0 or 1+ Glucose, ketones
AGM 2+-4+ 1+-4+ v 2+-4+ Blood; RBC, cellular, granular, and hyaline casts
Nephrotic syndrome 4+ 0 4+ Granular, waxy, hyaline,
and fatty castsChronic renal failure 1+-2+ Occ or
1+ 0 1+-3+ Granular, hyaline, and broad casts
Pyelonephritis 1+-2+ 0 or 1+ 4+ 0 or 1+WBC casts and hyaline casts; many pus cells; bacteria
Clinical Microbiology
Organisms may found in UrineBACTERIA
Gram positive Gram negativeStaphylococcus Escherichia colisaprophyticus Proteus speciesHaemolytic streptococci Pseudomonas aeruginosa
Klebsiella strains
Mycobacterium tuberculosisLeptospira interrogansChlamydiaMycoplasma
CandidaPARASITES
Schistosoma haematobium,Trichomonas vaginalisEnterobius vermicularisWuchereria bancrofti Onchocerca volvulus.
Organisms may found in CSFBACTERIA
Gram positive Gram negativeStreptococcus pneumoniae Neisseria meningitidis
Streptococcus agalactiae (Group B) Haemophilus influenzaeListeria monocytogenes Escherichia coli
Pseudomonas aeruginosa
Proteus specie Mycobacterium tuberculosisTreponema pallidum.
Organisms may found in CSFVIRUSES
CoxsackievirusesEchovirusarboviruses.herpes simplex 2 virusvaricella zoster virus
FUNGICryptococcus neoformans (mainly in AIDS patients)Aspergillus species.
PARASITESTrypanosoma species and Naegleria fowleriToxoplasma gondii (mainly in AIDS patients).
Bacterial meningitis
Glucose (mg/dL): Normal to ↓↓<40 mg/dL.
Protein (mg/dL) ↑↑ > 250 mg/dL.
WBCs (cells/µL) >500 (usually > 1000). Early: May be < 100.
Cell differential: Predominance of Neutrophils (PMNs)
Culture: PositiveOpening Pressure ↑
Fungal meningitisGlucose (mg/dL): <40 mg/dL (Low)
Protein (mg/dL) (moderate to ↑↑) 25 -500 mg/dL
WBCs (cells/µL) Variable (10 -1000 cells/µL) <500cells/µL.
Cell differential: Predominance of Lymphocytes
Culture: Positive (fungal)Opening Pressure Variable
TB meningitis
Glucose (mg/dL): <40 mg/dL (Low)
Protein (mg/dL) (moderate to ↑↑50 -500 mg/dL
WBCs (cells/µL) Variable (10 -1000 cells/µL) <500cells/µL.
Cell differential: Predominance of Lymphocytes
Culture: Positive for AFB
Opening Pressure Variable
Viral meningitis
Glucose (mg/dL): Normal (> 40 mg/dL.)
Protein (mg/dL) <100 mg/dL (moderate ↑)
WBCs (cells/µL) < 100 cells/µL.
Cell differential: Early: neutrophils. Late: lymphocytes.
Culture: Negative
Opening Pressure Usually normal
Blood CulturesBACTERIA
Gram positive Gram negativeStaphylococcus aureus Salmonella Typhi
Viridans streptococci Other Salmonella serovarsStreptococcus pneumoniae Brucella speciesStreptococcus pyogenes Haemophilus influenzaeEnterococcus faecalis Pseudomonas aeruginosaClostridium perfringens Klebsiella strainsAnaerobic streptococci Escherichia coli
Proteus speciesBacteroides fragilisNeisseria meningitidisYersinia pestis
Mycobacterium tuberculosis (HIV-associated tuberculosis), Leptospira species, Borrelia species,rickettsiae, Bartonella bacilliformis.
FUNGICandidaalbicansandother yeasts, e.g. Cryptococcus neoformans, and occasionally Histoplasma capsulatum
and other fungi that cause systemic mycoses.
Throat culture
BACTERIA
Gram positive Gram negativeStreptococcus pyogenes Vincent’s organismsCorynebacterium diphtheriaeCorynebacterium ulcerans
VIRUSESRespiratory virusesenteroviruses and herpes simplex virus type 1
FUNGICandida albicans and other yeasts.
pus, ulcer material and skin culture
BACTERIAGram positive Gram negative
Staphylococcus aureus Pseudonomas aeruginosaStreptococcus pyogenes Proteus speciesEnterococcus species Escherichia coliAnaerobic streptococci Bacteriodes speciesOther streptococci Klebsiella speciesClostridium perfringens Pasteurella speciesand other clostridiaActinomycetesActinomyces israeliAlso Mycobacterium tuberculosis
FUNGIHistoplasma c. duboisiiCandida albicansFungi that cause mycetoma
PARASITESEntamoeba histolytica
Effusions cultureSYNOVIAL FLUID
Gram positive Gram negativeStaphylococcus aureus Neisseria gonorrhoeaeStreptococcus pyogenes Neisseria meningitidisStreptococcus pneumoniae Haemophilus influenzaeAnaerobic streptococci Brucella species
Actinomycetes Salmonella serovarsEscherichia coliPseudomonas aeruginosaProteus
Bacteroides
Mycobacterium tuberculosis
Effusions culture
PLEURAL AND PERICARDIAL FLUIDS
BacterialGram positive Gram negative
Staphylococcus aureus Haemophilus influenzaeStreptococcus pneumoniae BacteroidesStreptococcus pyogenes Pseudomonas aeruginosaActinomycetes Klebsiella strains
Other enterobacteria
Mycobacterium tuberculosis fungiViruses especially coxsackie B virus
Effusions culture
ASCITIC FLUIDGram positive Gram negative
Enterococcus species Escherichia coliStreptococcus pneumoniae Klebsiella strainsStaphylococcus aureus Other enterobacteriaStreptococcus pyogenes Pseudomonas aeruginosaStreptococcus agalactiae BacteroidesViridans streptococciClostridium perfringens
Mycobacterium tuberculosisCandida species
Urogenital cultureURETHRAL SWABS
Neisseria gonorrhoeaeChlamydia trachomatis (serovars D-K)UreaplasmaMycoplasmaTrichomonas vaginalis.
Urogenital cultureCERVICAL SWABSFrom non-puerperal women:
Neisseria gonorrhoeae, Chlamydia trachomatis (serovars D-K),Streptococcus pyogenes, herpes simplex virus.
From women with puerperal sepsis or septic abortion:Streptococcus pyogenes, other betahaemolytic streptococci,
Staphylococcus aureus, Enterococcus species, anaerobic cocci, Clostridium perfringens, Bacteroides, Proteus, Escherichia coli and other coliforms, Listeria monocytogenes.
Urogenital cultureVAGINAL SWABS
Trichomonas vaginalisCandida speciesGardnerella vaginalis anaerobes
Stool sampleBACTERIA
Gram positive Gram negativeClostridium perfringens Shigella speciesClostridium difficile Salmonella serovars Staphylococcus aureus Campylobacter species
Escherichia coli (toxin)Vibrio cholerae 01, 0139Other Vibrio speciesAeromonas species
Mycobacterium tuberculosis
VIRUSESRotaviruses, Adenoviruses, , Astrovirus, calcivirus
PARASITESEntamoeba histolytica, Giardia lamblia
Sputum BACTERIA
Gram positive Gram negativeStreptococcus pneumoniae Haemophilus influenzaeStaphylococcus aureus Klebsiella pneumoniaeStreptococcus pyogenes Pseudomonas aeruginosa
Proteus speciesYersina pestisMoraxella catarrhalis
Mycobacterium tuberculosisMycoplasma pneumoniaeLegionella pneumophila.
FUNGI AND ACTINOMYCETESPneumocystis jiroveci, Blastomyces dermatitidis, Histoplasma capsulatum, Aspergillus species,
Candida albicans, Cryptococcus neoformans, and Nocardia species.
PARASITESParagonimus species
Serology
Widal test
negative Widal
absence of infection by S typhi and para typhiFalse negative• the carrier state• early treatment• hidden organism in bone or
joints• Technical errors
positive Widal
Typhoid feverFalse positive in: • previous immunization with
Salmonella antigen.• cross-reaction with non-
typhoidal Salmonella.• infection with malaria, Brucella,
other Enterobacteriaceae, dysentry, pneumonia, dengue, immune diseases
• Technical errors
O antigen: 4 fold ↑ if repeatedOr O antigen >1:160, H> 1: 320 in endemic areas
Brucella antibody
negative
absence of infection by Brucella infection
False negative• B canis infection• Technical errors
positive
• Brucella infection (except B canis)
False positive in: • infections with Francisella
tularensis, Yersinia enterocolitica, salmonella, Rocky Mountain spotted fever; vaccinations for cholera
• Technical errors
Positive titer ≥1:80↑≥ 4-fold in serum specimens obtained >2 weeks apart.
C-reactive protein (CRP)Positive titre: >6 mg/dLPositive in: • InflammationFalse positive in: • High protein diet• Smoking• Aging• Pregnancy or contraceptive use• Metabolic syndrome (insulin resistance)• Diabetes• Elevated triglycerides• Cancer
Rheumatoid factor (RF)
Positive titre: >8 mg/dLPositive in: • Rheumatoid arthritis (75-90%), False positive in • Other auto immune diseases• Drugs: methyldopa, others.• 1-4% of normal individuals, acute immune responses (eg, viral
infections, including infectious mononucleosis and viral hepatitis), chronic bacterial infections (tuberculosis, leprosy, subacute infective endocarditis), and chronic active hepatitis
False negative:• 20% of Rheumatoid arthritis
Antistreptolysin O titer (ASO)
Positive titre: >200 IU/mL• Detects antibody to the antigen streptolysin O produced by
group A streptococci.Titer rises to a peak at 4-6 weeks and may remain elevated for 1 year.
Positive in: • Streptococcal infection (eg, upper airway infections,
scarlet fever)• post-streptococcal infection complication (eg,
glomerulonephritis and rheumatic fever). False positive in• Some bacterial infections.
Hepatitis A antibody (Anti-HAV)
Positive in: • IgM: Acute hepatitis A• IgG: convalescence from hepatitis AIgM antibody is detectable within a week after
symptoms develop and persists for 6 months.IgG appears 4 weeks later than IgM and persists
for years.
Hepatitis B surface antigen (HBsAg)In hepatitis B virus infection HBsAg is • detectable 2-5 weeks before
onset of symptoms• peaks at the time of onset of
clinical illness.• persists for 1-5 months• Declining with resolution of
clinical symptoms.Positive in: • Acute hepatitis B • chronic hepatitis B (persistence
of HBsAg for >6 months, positive HBcAb [total])
• HBsAg positive carriers..
HBV markers
Hepatitis B markers
Hepatitis C antibody (HCV-Ab)
Detects antibody to HCVPositive in:
HCV infection
False positive:autoimmune liver disease Hypergammaglobulinemia
False negative:immunosuppressed patientslong-term hemodialysis.
HCVANTI-HCV HCV RNA (PCR) INTERPRETATION
Negative Negative No infection
Positive Positive HCV present (acute or chronic infection)
Negative Positive•Chronic infection in immunosuppressed patient•Early infection
Positive Negative•Resolved infection•Treated infection•False-positive anti-HCV test
HIV antibody
• HIV antibody test is considered positive only when confirmed by a Western blot analysis or immunofluorescent antibody test (IFA).
Positive in: • HIV infection
Toxoplasma antibodys
Toxo IgGToxo IgMPositive in: • IgM: Acute or congenital toxoplasmosis• IgG: previous toxoplasma exposurefalse-positive • SLE, HIV infection, positive rheumatoid factor,
positive ANA.
AUTOANTIBODIES: ASSOCIATIONS WITH CONNECTIVE TISSUE DISEASES
Disease Test Sensitivity, Specificity Other Disease
CREST Anti-centromere antibody CREST (70-90%, high) Scleroderma (10-15%), Raynaud disease (10-30%).
SLE
ANA SLE (>95%, low) RA (30-50%), scleroderma (60%), Sjogren (80%).
anti-ds-DNA SLE (60-70%, high) Lupus nephritis
Anti-Smith antibody (anti-Sm) SLE (30-40%, high)
Mixed connective tissue disease (MCTD)
Anti-ribonucleoprotein antibody (RNP)
MCTD (95-100%, low) Scleroderma (20-30%, low)
SLE (30%), Sjogren, RA (10%), discoid lupus (20-30%).
Rheumatoid arthritis (RA)
Rheumatoid factor (RF), Anti-CCP Rheumatoid arthritis (50-90%) Other rheumatic diseases,
chronic infections, elderly
Scleroderma Anti-Scl-70 antibody Scleroderma (15-20%, high)
Sjogren syndrome Anti-SS-A/Ro antibody Sjogren syndrome (60-70%, low) SLE (30-40%), RA (10%), subacute cutaneous lupus, vasculitis.
Wegener granulomatosis
Anti-neutrophil cytoplasmic antibody (ANCA)
Wegener granulomatosis (systemic necrotizing vasculitis) (56-96%, high)
Crescentic glomerulonephritis or other systemic vasculitis (eg, polyarteritis nodosa).
Clinical Chemistry
Glucose
HyperglycemiaPhysiologic
hard physical activity,strong emotions, e.g., fear.
Pathologic• Diabetes Mellitus Type 1, 2• Gestational diabetes• Chronic renal failure• Chronic pancreatitis• Glucagonoma• Hyperthyroidism• Pancreatic cancer• Pancreatitis• Hypopituitarism, Hypothyroidism
HypoglycemiaPhysiologic
normal pregnancy (mild)neonates born to diabetic mothers.
Pathologic
Liver necrosis, adrenal cortical hypofunction, hepatic failure.
Fasting blood glucose 70-110mg/dL2 hours post prandial <200 mg/dL
Alanine aminotransferase(ALT, SGPT, GPT)
Reference range: 10 - 46 U/LIncreased in:
Acute viral hepatitisbiliary tract obstructionLiver cirrhosisDrugs
Aspartate aminotransferase(AST, SGOT, GOT)
Reference range: 10 - 40 U/LIncreased in:
Acute viral hepatitis biliary tract obstruction (cholangitis, stone)cirrhosis Acute myocardial infarctionProgressive muscle diseaseHemolytic anemiaDrugs
ALT + AST
Viral Hepatitis• ↑20-50 even 100 times• Before clinical manifestations• Peak: 7th-12th day ↓ normal at 3th-5th week.• ALT>ASTToxic hepatitis: • as viral hepatitisInfectious mononucleosis + liver involvement: • ↑ ALT & AST up to 20 times
ALT + AST
Biliary obstruction:• ALT & AST higher in extrahepatic and chronic
obstructionCirrhosis: • ALT & AST: high normal ↑5 times• AST>ALTMalignancy• ALT & AST: normal ↑5-10 times
Bilirubin
DierctRR: 0.1-0.3 mg/dLIncreased in:
Bile duct obstructionHepatitisCirrhosisIntrahepatic cholestasis
IndirectRR: 0.1-0.7 mg/dL Increased in:
Crigler-Najjar syndromeGilbert's diseaseHemolytic anemiaHemolytic disease of the
newbornHepatitisPhysiological jaundiceTransfusion reaction
Albumin
Reference range: 3.5-5.2g/dL
Increased in: Dehydrationhemoconcentration.
Decreased in:Decreased hepatic synthesis
chronic liver disease, malnutrition, malabsorption
Increased losses nephrotic syndromeburnsenteropathy
Total Protein
Reference range: 6.3 - 8.2 g/dlIncreased in:
marked dehydration.
Decreased in: Protein-losing enteropathieschronic liver diseaseacute burnsnephrotic syndromesevere dietary protein deficiencymalabsorption syndrome
Alkaline phosphatase
Reference range: 45 - 150 U/LALP is found in liver, bone, intestine, and placenta.Liver• bil obstruction – extrahepatic : ↑↑ 3 times e.g. stone, cancer head of
pancreas)– Intrahepatic ↑↑ < 3 times (drugs, invasion by cancer
tissue)• Moderate ↑ to normal: parenchymal cells of liver
affected e.g. infectious hepatitis
Alkaline phosphatase
Bone• Physiologic– Children: growing bones– Healing bone fracture
• ↑↑ 10-25 times: Paget• Moderate ↑: Osteomalacia• 2 times: Rickets• Normal: Osteoporosis
Pregnancy: 3rd trimestre: 2-3 times
CreatinineReference range:
0.5-1.2 mg/dLIncreased in:
Acute or chronic renal failureurinary tract obstructionnephrotoxic drugs
Decreased in: Reduced muscle mass.
Creatinine clearanceRefernce range• Men
– Range: 97-137 ml/min/1.73 m2 • Women
– Range: 88-128 ml/min/1.73 m2
Increased in: High cardiac outputexercise
Decreased in: Acute or chronic renal failuredecreased renal blood flow (shock, hemorrhage, dehydration, CHF). Nephrotoxic drugs.
Uric acid
Increased in: Decreased renal excretion of Uric Acid
Primary idiopathic HyperuricemiaChronic Renal InsufficiencyDehydration or starvation ketosisDrugs
Overproduction of Uric AcidHGPRTase deficiencyMyeloproliferative disorderLymphoproliferative disorderChemotherapy
Decreased in: DrugsSIADHHemochromatosisProtein or purine deficient diet
Reference Range:Males: 3.4 to 7.0 mg/dLFemales 2.4–6.0 mg/dL
Urea
Reference Range: 20-40 mg/dlIncreased in:
intake of high-protein diet 12 hours before blood samplingRenal failure (acute or chronic)urinary tract obstructiondehydration, Nephrotoxic drugs (eg, gentamicin).
Decreased in: Hepatic failure, nephrotic syndrome, Cachexia
CholesterolReference Range:
Desirable: <200 mg/dLBorderline: 200-239 mg/dLHigh risk: >240 mg/dL
Increased in: Primary hypercholesterolemia Secondary disorders:
hypothyroidism, uncontrolled diabetes mellitus, nephrotic syndrome, biliary obstruction, Drugs.
Decreased in: Severe liver disease (acute hepatitis, cirrhosis)malnutritionmalabsorptionfamilial (Gaucher disease, Tangier disease)abetalipoproteinemia
Triglycerides
Reference Range:Desirable: <150 mg/dLBorderline: 150-199 mg/dLHigh risk: 200-499 mg/dLVery high risk: >500 mg/dL
Increased in: PrimaryDMHypothyroidism, nephrotic syndromebiliary tract obstructionDrugs
Decreased in:Tangier diseaseMalabsorptionparenchymal liver diseaseDrugs
CalciumReference Range: 8.5 - 10.3 mg/dLIncreased in:
Hyperparathyroidism, malignancies secreting parathyroid hormone-related protein (PTHrP) vitamin D excess, Bone diseases FamilialDrugs
Decreased in: Hypoparathyroidismvitamin D deficiencyRenal insufficiencymassive transfusionhypoalbuminemia.
CSF glucose and protein
CSF glucose
Reference range: 50 - 80 mg/dL (or 60-70% of the blood glucose).
CSF protein
Reference range: 15–45 mg/dL
Laboratory Hematology
Complete blood count Reference range
(adult) ↑ ↓
WBC 4-11 X109/L InfectionLeukemia
Some infectionsBM failure
WBC differential
Neutrophils: 55-75%Lymphocytes: 25-40%Monocytes: 2-8%Eosinophils: 1-4%Basophils: 0-1%
Bacterial: NeutrophiliaViral: Lymphocytosis
Some infectionsBM failure
Hb Male: 13.5-16 g/dLFemale: 12-15 g/dL
DehydrationPolycythemia
AnemiaBleeding
Platelets 150-450 X109/L Some infectionsThrombocytosis
BleedingThrombocytopenia
Erythrocyte sedimentation rate (ESR)Reference range: Male: <10 Female: <15 mm/h
↑ ↓
Anemiaincreased fibrinogenIncreased abnormal proteinsInflammationInfection
Marked ↑↑Collagen diseasesMalignancyTB
Polycythemia abnormal red cells, eg spherocytosissickle cells Cryoglobulins low fibrinogen
PT (INR) and APTT
PT APTT EXAMPLES
10 - 13.5 seconds, orINR of 0.8-1.1
30 to 45 seconds Reference ranges
↑ Normal Liver disease, ↓vitamin K, ↓factor VII,anticoagulation drug therapy
Normal ↑ ↓factor VIII, IX, or XI, von Willebrand disease
↑ ↑ ↓ factor I, II, V or X, severe liver disease, DIC
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