Synovial Fluid (Part II) Flashcards
(51 cards)
Under Microscopic Examination
total cell count
differential leukocyte count
crystal examination
Total leukocyte counts should be performed as soon as ______ following arthrocentesis
1 hour
Leukocyte counts over 50,000/uL require dilution which should be done with ______ to avoid mucin clot formation and cell clumping
saline, not acetic acid
Their use risks clogging the machine aperture or obtaining spuriously high cell counts from non-WBC particles (crystals, fat globules)
Flow cell-based automated cell counters
Pretreatment of highly viscous SF samples with ______ improves automated cell counting using instruments
hyraluronidase
Leukocyte counts greater than 10,000/uL, and often gretaer than 50,000 are characteristic of
crystal-induced arthritis (e.g., gout, pseudogout)
chronic inflammatory arthritis (RA, SLE, ankylosing spondylitis)
septic arthritis
These clinical conditions usually have total WBC counts less than 10,000/uL
Osteoarthritis
Osteochondritis dissecans
trauma
synovioma
If a large number of RBCs interferes with leukocyte count, they may be lysed with dilution with
0.3 normal saline or 1% saponin in saline
The upper reference level for SF leukocyte
150 to 200/uL
Preparation preferred over smears from centrifuged SF because the cell morphology is significantly better preserved
Cytospin preparations
Treatment with this may be necessary to produce thin smears in viscous specimens
Hyaluronidase
Used effectively to produce good-quality preparations of SF for microscopic examination
Liquid-based thin-layer processing instruments
Normally account 20% of SF leukocyte
Neutrophils
Neutrophils generally exceed 50% in
urate gout
pseudogout
RA
Neutrophils most often exceed 75% in
acute bacterial arthritis
In differential leukocyte cell count, when 75% of the neutrophils are used as a cutoff, the sensitivity for an inflammatory process is about _____ and the specificity is _____
sensitivity: 75%
specificity: 92%
Neutrophils may frequently exhibit degenerative changes and may contain ______ that is thought to consist of immune complexes
bacteria
crystals
lipid droplets
vacuoles
dark blue to black granular inclusions
The presence of ____ in patients with RA may indicate a poorer outcome
Ragocytes
Present in patients with lupus arthritis
Lupus erythematosus (LE) cells
Most often neutrophils that have phagocytosed the nuclei of degenerating cells
Lupus erythematosus (LE) cells
normally constituting about 15% of SF cells
Lymphocytes
Leukocyte prominent in early RA and other autoimmune disorders, as well as in chronic infections
Lymphocytes
The most common cells present in normal SF
Monocytes and Macrophages
Accounting for approximately 65% of the cell count
Monocytes and Macrophages
