Body fluids—Chemistry, serous, synovial Flashcards
most common chemical tests performed on CSF
- glucose
- protein
- IgG
- CSF electrophoresis
- myelin basic proteins
CSF protein RR
15-45 mg/dL
0.6% concentration of serum
—– protein identifies fluid as CSF
TAU
major Ig in CSF
IgG
3 proteins absent from CSF
IgM
fibrinogen
beta lipoprotein
causes of ↓ CSF protein
- leakage/trauma
- water intoxication
- rapid CSF production
- recent puncture
causes of ↑ CSF protein
- damage or inflammation of meninges
- infection
- trauma
- neoplasms
- cerebral infarction
CSF protein >500 mg/dL
bacterial meningitis
volume CSF taken depends on…
patient volume
opening pressure
CJD testing CSF sample handling
-80° freezer
primary and secondary CSF proteins
albumin
prealbumin
major CSF beta globulin
transferrin
TAU
carbohydrate-deficient transferrin
seen in CSF, not in blood
used to identify CSF
higher CSF protein values found in…
infants
people over 40
2 major techniques for measuring CSF protein
turbidity production
dye-binding ability
CSF/serum albumin index is used for…
BBB integrity
<9: intact BBB
CSF/serum albumin index
CSF albumin (mg/dL)/serum albumin (g/dL)
2 causes of elevated IgG in CSF
- increased production (MS)
- leakage (damaged BBB)
IgG index RR
0.25-0.85
IgG index
(CSF IgG)(serum albumin)/(serum IgG)(CSF albumin)
↑ IgG index
local production of IgG
MS
BBB is not damaged
↓ IgG index
strokes
tumors
meningitis
BBB is damaged
IgG index values >—— indicate IgG production within the CNS
0.70
bands in the gamma region of CSF electrophoresis
derived from clones of immunocompetent cells
oligoclonal bands
oligoclonal bands in CSF
no bands in serum
MS
oligoclonal bands in CSF and serum
- leukemia/lymphoma
- HIV
- viral infection
represent inflammation in the CNS
oligoclonal bands
Presence in CSF indicates recent demyelination
myelin basic proteins (MBPs)
used to monitor MS course/tx
MBP
↑ gamma globulins in CSF due to Bence Jones proteins crossing BBB
MM
CSF glucose RR
60-70% plasma glucose
around 40-70 mg/dL
CSF glucose procedure
draw plasma glucose 2 hours prior for comparison
pellicle
a delicate cobweb clot in CSF seen in tubercular meningitis
Decreased CSF glucose values are caused primarily by…
- alterations in the mechanisms of glucose transport across thee BBB
- increased use of glucose by the brain cells
normal CSF WBCs
0-5/uL
CSF lactic acid RR
10-24 mg/dL
pellicle formation due to…
marked increase of proteins
use of CSF lactic acid
- Diagnosis and management of meningitis
- Monitor head injuries
CSF ——— will fall rapidly when meningitis tx is successful
lactic acid
false increase of CSF lactic acid
hemorrhagic specimens or traumatic tap
RBCs have lactate
- markedly ↓ CSF glucose
- lactate >35
- WBC >50
- ↑ % neuts
bacterial meningitis
- normal CSF glucose
- normal lactate
- WBC >50
- ↑ % lymphs
viral meningitis
- ↓ CSF glucose
- lactate >25
- WBC >50
- ↑ % lymphs
tubercular meningitis
- normal CSF glucose
- lactate >25
- WBC >50
- ↑ % lymphs
fungal meningitis
if CSF has <50 WBCs…
think about degenerative neurologic disorders
CSF glutamine RR
8-18 mg/dL
function of glutamine
produced by brain cells from ammonia + 𝛼-ketoglutarate
serves to remove toxic ammonia from CNS
glutamine preferred over ammonia because…
ammonia is volatile
CSF glutamine > —— correlates with coma
35
causes of ↑ CSF glutamine
- Reye’s syndrome
- liver disease
- disturbance of consciousness
3 serous cavities of body
- pleural
- pericardial
- peritoneal
2 serous membranes
parietal
visceral
fluid buildup in serous cavities
effusion
main causes of effusions
- CHF increasing BP
- hypoproteinemia decreasing oncotic pressure
- inflammation increasing capillary permeability
- infection
- malignancy
- lymphatic obstruction
2 types of effusions
transudate
exudate
fluid accumulation due to a systemic disease affecting filtration/reabsorption balance
transudate
fluid accumulation due to disorders involving the membrane surfaces
exudate
characteristics of transudates
Transudates
- transparent
- fluid:serum protein <0.5
- WBC <1000
- no spontaneous clotting
- serum-ascites albumin gradient >1.1
characteristics of exudates
Exudates
- cloudy
- fluid:serum protein >0.5
- WBC >1000
- spontaneous clotting possible
- serum-ascites albumin gradient <1.1
(transudates/exudates) usually require less testing
transudates
3 types of needle aspirations of serous fluid
- thoracentesis
- pericardiocentesis
- paracentesis
types of tubes of serous fluid drawn
- EDTA: hematology
- sterile heparinized/SPS: micro, cytology
- clotted/heparin: chemistry, serology
——— fluid specimens for pH are STAT and should be maintained anaerobically
serous
the ——– cavity is not a true cavity but becomes one when a disease state is present
pleural
causes of PE transudates
- CHF
- nephrotic syndrome
- cirrhosis
causes of PE exudates
- infection
- pulmonary infarction
- pancreatitis
- SLE
- RA
- cancer
- trauma
2 types of milky PE and their causes
- chylous: triglycerides; thoracic duct leaking; stain with sudan III
- psudeochylous: cholesterol; chronic inflammatory condition
how to differentiate 2 causes of bloody PE
- Hemothorax (trauma): Hct >50% or >blood Hct
- Hemorrhagic effusion (membrane damage): Hct <50% or similar to blood Hct
brown PE
rupture of amoebic liver abscess
black PE
aspergillus
viscous PE
malignant mesothelioma (↑ hyaluronic acid)
↓ glucose in PE
- RA
- purulent infection
↑ lactate in PE
bacterial infection
↓ pH in PE
- pneumonia not responding to antibiotics
- esophageal rupture (pH <6.0)
↑ ADA in PE
- tuberculosis
- malignancy
↑ amylase in PE
- pancreatitis
- esophageal rupture
- malignancy
pH of PE <7.0 indicates…
need for chest tubes
Carcinoembryonic antigen
GI malignancy
CA125
uterine and ovarian malignancy
causes of pericardial transudates
- autoimmune disorders
- uremia
- hypothyroidism
causes of pericardial exudates
- infection
- MI
- cancer
- trauma
amount of pericardial serous fluid
10-50 mL
causes of bloody pericardial fluid
- accidental puncture
- misuse of anticoags
suspected when cardiac tamponade (compression) is heard by physician
pericardial effusion
WBC >1000 and high % neuts in pericardial fluid
bacterial endocarditis
acid fast stain and adenosine deaminase
tubercular effusion
peritoneal effusion
ascites
causes of peritoneal transudates
- CHF
- nephrotic syndrome
- cirrhosis
causes of peritoneal exudates
- peritonitis (infection)
- neoplasms
- pancreatitis
- trauma
recommended over fluid:serum protein and LD ratios to detect peritoneal transudates of hepatic origin
serum-ascites albumin gradient (SAAG)
SAAG >1.1
peritoneal transudate of hepatic origin
SAAG <1.1
exudative peritoneal effusions
normal saline introduced into peritoneal cavity
detect abdominal injuries
peritoneal lavage
SAAG =
serum albumin - fluid albumin
RBC count >——— from peritoneal lavage indicates blunt trauma
100,000
eos in peritoneal lavage
allergic reactions to equipment
air in the cavity
normal WBC in peritoneal fluid
<500
green peritoneal fluid
bile, gallbladder, pancreatic disorders
↑ BUN/creatinine in peritoneal fluid
ruptured or punctured bladder
↑ ALP in peritoneal fluid
intestinal perforation
movable joints
diarthroses/synovial
functions of synovial fluid
- prevents friction
- absorbs shock of joint compression
- provides nutrients to cartilage
excluded from synovial fluid
HMW proteins
cells that secrete synovial fluid
synoviocytes
contribute to viscosity of synovial fluid
polymerization of hyaluronic acid
some protein
4 classifications of arthritis
- Noninflammatory: degenerative, osteoarthritis
- Inflammatory: immunologic, lupus erythematosus (LE), rheumatoid arthritis (RA), Lyme disease, crystal-induced (gout and pseudogout)
- Septic: microbial infection
- Hemorrhagic: trauma, tumors, coagulation deficiencies
normal viscosity of synovial fluid
able to form a 4-6 cm string
normal synovial fluid WBC
<200
normal synovial fluid neuts
<25%
normal synovial fluid glucose
<10 mg/dL lower than BG
normal synovial fluid total protein
<3 g/dL
needle aspiration of synovial fluid
arthrocentesis
normal amount of knee synovial fluid collected
3.5 mL
tubes collected for synovial fluid
- sterile heparinized/SPS: micro
- liquid EDTA (no powdered): hematology
- heparinized/clotted: other tests
- sodium fluoride: glucose (ideally)
test synovial fluid STAT to avoid…
cellular lysis
changes in crystals
used to assess hyaluronate polymerization in synovial fluid
Ropes/mucin clot test
add 2-5% acetic acid
normal fluid forms a solid clot
Ropes test results
- good - solid clot
- fair - soft clot
- low - friable clot
- poor - no clot
can ID fluid as synovial
add acetic acid
normally forms a clot
main crystals found in synovial fluid
- monosodium urate (MSU) in gout
- calcium pyrophosphate dihydrate (CPPD) in pseudogout
causes of MSU crystals in synovial fluid
- impaired purine metabolism
- high purine foods
- leukemia chemo
- decreased renal excretion of uric acid
causes of CPPD in synovial fluid
- degenerative arthritis
- elevated Ca++
crystals from calcified cartilage degeneration
hydroxyapatite
calcium phosphate
crystals from RA, SLE
cholesterol
crystals following knee injections
corticosteroid
crystals in renal dialysis pts
CaOx
artifacts that may be found in synovial fluid
- starch
- powdered anticoags
- dust
- scratches
- polyethylene fragments from artificial joints
where can crystals be found in synovial fluid?
extracellular, intracellular, or both
ability to refract light in 2 directions
birefringent
magnified birefringent images appear bright or colored against black background
polarizing microscopy
MSU crystal characteristics
- needle shaped
- intracellular and extracellular
- negative birefringence
- slow vibration: yellow; more intense than CPPD
- fast vibration: blue; more intense than CPPD
CPPD crystal characteristics
- rod, needle or rhombic shaped
- intracellular and extracellular
- positive birefringence
- slow vibration: blue; less intense than MSU
- fast vibration: yellow; less intense than MSU
used to observe birefringence of crystals
separates light ray into fast and slow moving vibrations
red compensator crystal
the compensator aligns crystals with the —— vibration
slow
cholesterol crystals characteristics
- notched rhombic plates
- extracellular
- negative birefringence unless stacked
corticosteroid crystal characteristics
- flat, variably shaped plates
- primarily intracellular
MSU molecules run ——– to the long axis, aligned with slow vibration; fast light is impeded, producing a ——— color (negative birefringence)
parallel
yellow
CPPD molecules run ——— to long axis and impede the slow light producing a ——– color (positive birefringence)
perpendicular
blue
why is chemical testing not considered clinically important on synovial fliud?
ultrafiltrate of plasma – approximately the same chemically
↑ lactic acid in synovial fluid
septic arthritis caused by GPC and GNR
↓ lactic acid in synovial fluid
arthritis caused by Ngon
synovial fluid lactic acid >—— mmol/L (—- mg/dL) indicate an immediate tx onset
9
81
used to monitor severity and prognosis of RA
enzymes in synovial fluid
used to monitor extent of joint inflammation
CRP and fibrinogen in synovial fluid
Borrelia Ab in synovial fluid
Lyme
ultrafiltrate of serum
no additional material from membrane cells
serous fluid
serous fluid production through ——– membrane
reabsorption into lymphatic system through ———– membrane
parietal
visceral
blood sample should be drawn at the same time as ——- fluid
serous
most significant test on pleural fluid
diff
normal cells in pleural fluid
- lymphs
- mesothelial cells
large
round with round nucleii
blue cytoplasm, dark chromatin
may resemble lymphs, plasmas and malignants
mesothelials
mesothelials can become…
macros
eos in pleural fluid
- trauma (air or blood in cavity)
- allergic reaction
- parasitic infection
characteristics of reactive mesothelials
- clusters
- varying amounts of cytoplasm
- eccentric nuclei
- prominent nucleoli
- can be giant and multinucleated
characteristics of malignant cells that differentiate them from mesothelials
- nuclear irregularities
- vacuoles in cytoplasm, nucleus
- hyperchromatic nucleoli
- clumps with cytoplasmic molding
- high N:C ratio
important exam for pericardial fluid
cytologic exam for malignant cells
frequently encountered malignant cells in pericardial fluid
- metastatic lung carcinoma
- breast carcinoma
most common cause of ascitic transudate
hepatic disorders
origins of peritonitis
- perforation of intestine
- ruptured appendix
special macrophages that may be found in peritoneal fluid
lipophages
contain concentric striations of collagen-like material
psammoma bodies
↑ Ca++ in fluid
seen in benign conditions, and ovarian and thyroid cancer
psammoma bodies
used to thin synovial fluid for analyzer
hyaluronidase
no additives in synovial fluid for…
crystal analysis
never used as diluent for synovial fluid
used instead
acetic acid (clots)
saline
when to dilute synovial fluid for cell count
when it is not transparent
normal WBC in synvoial fluid
<200
normal cells in synovial fluid
- monos/macros
- synovial lining cells (same as mesothelials)
indicates septic arthritis
↑ neuts in synovial fluid
often pyknotic
indicates non-septic inflammation in joints
↑ lymphs in synovial fluid
neutrophils in synovial fluid with cytoplasmic blue granules filled with RF immune complexes
ragocytes
found in RA
macrophages in synovial fluid with ingested neutrophil
Reiter cells
Reiter syndrome, nonspecific inflammation
3 signs of Reiter syndrome
- red eyes
- urinary tract problems
- arthritic (overactive macros)
very dark pink cells in synovial fluid
chondrocytes
many chondrocytes
osteoarthritis
neutrophil in synovial fluid with ingested “round body”
LE cell
found in SLE, RA
how to count cells on amniotic fluid
count all nucleated cells (WBCs + SECs)
normal cell to see in amniotic fluid
SEC
