Cerebrospinal Fluid

1. 1

2. Cerebrospinal Fluid
 Physiologic system to supply nutrients to
nervous tissue, move metabolic waste &
mechanical barrier to cushion the brain &
spinal cord against trauma
 Produce 500 ml/day
 Ultrafiltration and secretion through the
choroid plexus
 Obtained by lumbar puncture, cisternal
puncture, lateral cervical puncture or
ventricular cannulas
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3. Formation of Cerebrospinal
Fluid
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4. 4

5. Specimen Collection
 Routinely by lumbar puncture between
3rd, 4th or 5th vertebrae
 Up to 20 mL CSF may normally be moved
 Collected in 3 sterile tubes:
1. Tube 1: chemical & serologic tests
2. Tube 2: microbiology
3. Tube 3: cell count & differential
 Examination should be performed
immediately (<1 hr)
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6. Indications
 Indications:
1. Meningeal infection
2. Subarachnoid hemorrhage
3. CNS malignancy
4. Demyelinating disease
Opening Pressure:
90-180 mmH2O
>200 mmH2O→20mL
<90 mmH2O →no withdrawn
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7. Disease detected by CSF
Examination
 High sensitivity, high specificity
bacterial, TB, fungal meningitis
 High sensitivity, moderate specificity
viral meningitis, subarachnoid hemorrhage
 Moderate sensitivity, high specificity
meningeal malignancy
 Moderate sensitivity, moderate specificity
intracranial hemorrhage, viral encephalitis,
subdural hematoma
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8. Gross Examination
 Normal CSF:
clear and colorless
viscosity similar to water
 Turbidity
leukocyte >200cells/µL
erithrocyte > 400cells/µL
 Clot formation
traumatic tap, complete spinal block,
suppurative and tuberculous meningitis
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9. Gross Examination
 Viscous
metastatic mucin-producing
adenomacarcinomas
cryptococcal adenocarcinomas
 Xanthochromia
pink, orange or yellow
due to RBC lysis or Hb breakdown
bilirubin, protein >150mg/dL, carotinoids,
melanin, rifampicin therapi, contamination
of detergent or methiolate disinfectan
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10. Microscopic Examination
Total Cell Count
 Leukocyte: normal 0-5 cells/µL, neonates <30 cells/µL
 Use Fuch Rosenthal or Neubauer counting chamber
Differential Count
 Performed on a Wright’s-stained smear
 Normal: primarily lymphocytes & monocytes
adult: lymphocytes : monocytes = 70:30
children: monocytes more prevalent (up to 80%)
 Neutrophil: e.g bacterial meningitis
 Lymphocytes: e.g viral & Tb meningitis
 Eosinophil: e.g parasitic & fungal infections
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11. Chemical Analysis
 Total Protein
Derived from plasma, concentration<1%
blood level (15-45 mg/dL)
elevated CSF protein:
Increased permeability of BBB (meningitis,
hemorrhage)
Decreased resorption at arachnoid villi
Mechanical obstruction (tumor)
Increase intrathecal immunoglobulin
synthesis (Guillain-Barre synd, multiple
sclerosis)
Method: Turbidimetric, colorimetric
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12. Chemical Analysis
 Glucose
derived from blood glucose
fasting CSF glucose 50-80mg/dL
60% plasma values, normal ratio 0.3-0.9
Hypoglycorrhacia:
bacterial, tuberculous and fungal
meningitis
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13. Chemical Analysis
Lactate
 Reference: 9.0-26.0 mg/dL
 differentiating viral meningitis from
bacterial, mycoplasma, fungal & TB
meningitis
 Viral meningitis <35 mg/dL
 Bacterial meningitis >35 mg/dL
 Sensitivity & specificity 80-90%
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14. Chemical Analysis
 Enzymes
1. Lactate Dehydrogenase (LDH)
Normal < 40U/L
traumatic tap vs intracranial hemorrhage
elevated in bacterial meningitis
sensitivity & specificity 86% & 93%
2. Creatine Kinase (CK)
Normal < 5 U/L
elevated in demyelinating disease, seizures,
stroke, malignant tumors, meningitis & head injury
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15. Microbiological Examination
 Gram stain, bacterial antigen test, Limulus
Lysate assay
 Bacterial Meningitis
group B Streptococcus and Gram negative rods
Hemophilus influenza
Neisseria meningitidis & Streptococcus
pneumonia
 Viral meningitis
Enteroviruses (polioviruses)
 Fungal meningitis
Cryptococcus (in AIDS patients)
 Tuberculous meningitis 15

16. Differential Diagnosis of Meningitis
Bacterial Viral Tubercular Fungal
WBC count Elevated
1000-
100,000
Elevated
5-300
Elevated
100-600
Elevated
40-400
Cell present neutrophil Lympho-
cytes
Lympho-
cytes &
monocytes
Lympho-
cytes &
monocytes
Protein
elevated
Marked
80-500
Moderate
30-100
Moderate to
marked
50-300
Moderate to
marked
50-300
Glucosa Decreased
<40mg/dL
normal Decreased<4
5 mg/dL
Normal to
decrease
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Transudates & Exudates
Transudates: case3
increased capillary hydrostatic pressure or decreased
plasma oncotic pressure
 Congestive heart faillure
 Hepatic cirrhosis
 Hypoproteinemia
Exudates: case4
Increase capillary permeability or decreased lymphatic
resorption
 Infections: Tb, bacterial, viral pneumonia
 Neoplasms: metastatic Ca
 Extrapleural sources: pancreatitis, ruptured esophagus

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Light’s Criteria
Exudate: 1/more of following criteria
1. PF/S protein >0.5
2. PF/S LD > 0.6
3. PF LD >2/3 serum upper limit of normal
Sensitivity 98%, specificity 80%

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Gross Examination
Transudates Exudates
Color Pale yellow to
straw
Turbidity Clear Turbid/milky/
bloody
Odor - Fecalent:
anaerobic inf
Clot - +

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21. 21
Microscopic Examination
Transudates Exudates
Cell counting < 1000/µL > 1000/µL
Differential count :
Mesothelial cell
Neutrophilia (>50%)
Lymphocytosis
(>50%)
Eosinophilic (>10%)
negative
10% case
30% case
Cong heart
failure, trauma
Tb, empiema,
rheumatoid
Bacterial pneu,
pancreatitis
Tb, viral inf,
malignancy, SLE
parasitic/fungal
inf, drug rx,
rheumato

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Chemical Analysis
Transudates Exudates
Protein <3.0 g/dL >3.0 g/dL
Glucose = serum < 60mg/dL :
purulent
LDH PF/S <0.6
<200 IU/L
PF/S >0.6
>200 IU/L
Amylase ≤ serum ≤ serum
pH >7.4 >/<7.3

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Immunologic & Microbiological
Examination
 Immunologic:
1. Rheumatoid Factor
2. ANA titers
3. Complement levels
 Microbiological:
1. Gram’s stain
2. Acid-fast stain
3. culture

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Synovial Fluid
 Viscous liquid found in the joint cavities
 Ultrafiltrate of plasma combined with
hyaluronic acid produced by the synovial
cell
 Normal: < 3.5mL
 Functions:
1. Acts as lubricant and adhesive
2. Provides nutrients for the avascular
articular cartilage

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Synovial Fluid

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Specimen Collection
 Arthrocentesis
 Steril, disposable needles and plastic syringe
 Specimen:
1. EDTA: cell count & diff count
2. Na-Heparinized : chemical & immunologic test
3. Plain: microbiologic test & crystal examination
 Oxalate, Li-heparin and EDTA powder avoided

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Gross Examination
Color
 evaluated in a clear glass tube against a white
background
 Normal: colorless to pale yellow
 noninflammatory/ inflammatory dis: straw to
yellow (xanthochromia)
 Septic: yellow, brown, green

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Clarity
 Related to the number and type of particles
within synovia
 Normal: transparent
 Translucent: leukocytes
 Opaque: massive crystals
 Milky opalescent: abundance of cholesterol
crystal
Gross Examination

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This is the colorless, clear
synovial fluid from a patient with
osteoarthritis accompanied by a
low synovial-fluid white cell count.

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Cloudy but translucent
inflammatory synovial fluid were
taken from a patient with
rheumatoid arthritis (left) and
Gout (right).

32. 32
This bloody fluid with a
thicker layer of lipid
material separated after
centrifugation was
aspirated from a patient
with a tibial fracture into
the joint space.

33. 33
Synovial fluid taken from a
patient with an inflammation
process

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Microscopic Examination
Total Cell Count
 1 hour after arthrocentesis
 Hemacytometer or automated cell counter
 Incubated with hyaluronidase
 Normal: <150-200/ µL

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Differential Count
Normal:
 Neutrophils 20%
 Lymphocytes 15%
 Monocytes & macrophages 65%
 Eosinophilia 2%
Elevated:
 Neutrophils: inflammatory, Gout & RA
 Lymphocytes: early RA, chronic infection
 Monocytes: viral arthritis
 Eosinophilia: RA, metastatic carcinoma, parasitic inf
Microscopic Examination

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Crystal Examination
 Gout: crystal deposition in articular tissue
 1. monosodium urate monohydrate (MSU)
2. calcium pyrophosphate dihydrate (CPPD)
3. apatite
4. basic calcium phosphate (BCP)
 Polarized light microscope
 1. MSU: Gout, septic arthritis
2. CPPD: degenerative arthritis, hypo-Mg,
hemochromatosis
Microscopic Examination

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Synovial Fluid Crystal
Crystal Shape
Monosodium urate Needles
Ca pyrophosphate Rods
cholesterol Notched rhombic
plates
apatite Small needles
corticosteroid Flat, variable
shape plates

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Monosodium urate crystals
Ca pyrophosphate crystals

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Chemical Analysis
 Mucin clot test: add acetic acid
 Glucose: Normal <10 mg/dL
 Protein: Normal 1.38 g/dL
 Lipids:
1. cholesterol-rich psedochylous: chronic RA
2. lipid droplets: trauma
3. chylous effusion: RA, SLE, filariasis,
pancreatitis, trauma

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Immunologic & Microbiological
Examination
1. Immunologic studies
 Rheumatoid Factor (RF)
 Complement
2. Microbiological Examination
 Gram’s stain
 Ziehl-Neelson
 Culture

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Pleural Fluid
 Pleural cavity: between mesothelium of
visceral and parietal pleura
 Normal: small amount of fluid
 Plasma filtrate derived from capillaries of
the parietal pleura, reabsorbed through the
lympatics and venules of the visceral
pleura
 Effusion: accumulation of fluid
 Specimen collection: Thoracentesis
 In EDTA tube: cell counts & differential

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Pericardial Fluid
 Normal: 10-50 mL
 Produced by transudative process
 Effusion: Inflammatory, malignant,
hemorrhagic processes
 Obtained: pericardiotomy,
pericardiocentesis

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Gross Examination
 Normal: pale yellow and clear
 Infection: turbid effusion
 Uremia: clear & straw colored effusion
 Chylous effusion: milky appearance
Microscopic Examination
 Leukocyte count:
>10 000/µL: bacterial, TB, malignant
Pericardial Fluid

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Chemical Analysis
 Protein
>3.0g/dL: exudates
 Glucose
<40mg/dL: bacterial, TB, malignant
 pH
<7.10: rheumatic & purulent condition
7.20-7.40: malignant, uremia, TB
 Enzymes
LD >300U/dL & fluid/serum LD ratio>0.6:
exudates
Pericardial Fluid

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Peritoneal Fluid
 Ultrafiltrate of plasma
 Peritoneal effusion: ascites
 Normal: <50mL
 Paracentesis, Diagnostic Peritoneal
Lavage (DPL), peritoneal dialysis,
peritoneal washing
 Specimen collection:EDTA

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Abdomen symetrically distended secondary to fluid build up in
peritoneal cavity. Skin is also yellowed due to hyperbilirubinemia.

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Gross Examination
 Transudates: pale yellow & clear
 Exudates: cloudy/ turbid
 Acute pancreatitis & cholecystitis: green
 Malignancy & TB: bloody
 Chylous & pseudochylous: milky fluid
Peritoneal Fluid
 Microscopic Examination
 Bacterial peritonitis:
leukocyte >500/µL, >50% neutrophil
 Eosinophilia (>10%): chronic inflammatory process

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Chemical Analysis
 Protein: little value
 Low glucose: TB peritonitis & malignancy
 Elevated amylase: pancreatitis, gastrointestinal
perforation
 Elevated alkaline phosphatase: intestinal
perforation
 Elevated urea/ creatinine: ruptured bladder
Peritoneal Fluid

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References
1. Clinical Diagnosis and Management by
Laboratory Methods.Henry JB. 20th ed. 2001.
WB Saunders co: Philadelphia London
2. Urinalysis and Body Fluid. Strasinger SK. 2nd
ed.1989. F.A. Davis Co: Philadelphia
3. Basic Medical Laboratory Techniques.
Estridge BH, Reynolds AP, Walters NJ. 4th ed.
2000. Delmar: Africa Australia

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Thank you very much