MSK labs

Question 1

what are inflammatory marker tests + give examples

Answer 1

test that detects inflammation in body
high in acute and chronic inflammatory states like infection, surgery, arthritis, autoimmune disorders
ESR, CRP (sensitive, non-specific)

Question 2

what influences inflammatory markers

Answer 2

age, gender (higher for women), obesity, chronic disease

Question 3

ESR (what it stands for, what it does, specific or non specific)

Answer 3

erythrocyte sedimentation rate aka sed rate
measures height of erythrocytes that fall through plasma over a period of 1hr
non-specific

Question 4

CRP (what it stands for, what it does)

Answer 4

C-reactive protein
an acute phase reactant protein that checks for inflammation

Question 5

when else can ESR be elevated

Answer 5

anemia, renal disease, obesity

Question 6

what is a normal ESR

Answer 6

<20mm/hr (<10 for men)

Question 7

abnormal WBC indicates

Answer 7

infection or inflammation

Question 8

what happens to neutrophils in settings of disease

Answer 8

morphologic change
immature neutrophils with bands

Question 9

normal range for hemoglobin!!

Answer 9

male: 13.5-17.5
female: 12.0-15.5

Question 10

what labs would you do to help diagnose gout

Answer 10

arthrocentesis, uric acid (elevated), WBC (should be close to normal unless septic arthritis)

Question 11

gold standard for diagnosing gout

Answer 11

joint aspirate
gout - needle shaped negatively birefringent crystals
pseudogout - rhomboid shaped positively birefringent crystals

Question 12

why might uric acid levels be high

Answer 12

overproduction, underexcretion (most common)

Question 13

how long should you wait to test for IgM antibodies

Answer 13

1-2 weeks

Question 14

how long should you wait to test for IgG antibodies

Answer 14

2-6 weeks

Question 15

serology test is commonly done for

Answer 15

lyme disease
can remain elevated despite successful therapies
looking for IgM and IgG antibodies

Question 16

rheumatoid factor (RF) is positive in what diseases

Answer 16

RA, sjogren syndrome, SLE

Question 17

anti-CCP antibody (what it tests for, what condition its associated with)

Answer 17

marker for progressive, erosive joint disease
highly associated with RA (positive)
a neg RF and a neg anti CCP is better at excluding RF than either test alone

Question 18

tests that support RA diagnosis

Answer 18

ESR, CCP, CRP, CBC

Question 19

ANA

Answer 19

antibody present in various autoimmune diseases
strongly associated with active lupus cases
more dilute = stronger positive

Question 20

lab tests that support SLE diagnosis

Answer 20

CBC (pancytopenia), VDRL (false positive), RPR (negative), ESR

Question 21

what labs are positive in sjogrens syndrome

Answer 21

RF, SS-A, SS-B

Question 22

creatinine kinase (CK)

Answer 22

muscle enzyme/muscle test
elevations indicate muscle damage/breakdown (acute or chronic)

Question 23

what type of CK is found in skeletal muscle

Answer 23

MM-type (CK-MM)

Question 24

what type of CK is found in cardiac muscle

Answer 24

MB-type (CK-MB)

Question 25

in what conditions would you have an elevated CK

Answer 25

dermatomyositis, polymyositis (both problematic), PAN exercise, muscle biopsy, iatrogenic (not problematic)

Question 26

aldolase (found where, what does it indicate)

Answer 26

enzyme found in skeletal muscle, liver and brain elevation may indicate muscle breakdown less specific and sensitive than CK

Question 27

lactate dehydrogenase

Answer 27

general indication of cell injury enzyme with muscle and heart subunits

Question 28

when can LDH be inaccurate

Answer 28

if blood sample is hemolyzed

Question 29

TB gold

Answer 29

serum test for latent TB infection

Question 30

limitations of TB test

Answer 30

HIV infection, poor sensitivity + specificity for active TB, high cost

Question 31

what labs would you do for multiple myeolma

Answer 31

SPEP, UEP (24hr urine), CBC, ESR, CRP

Question 32

hemoglobin is decreased in what msk condition

Answer 32

polymyalgia rheumatica

Question 33

what does d-dimer indicate

Answer 33

thrombolysis only used if you are NOT suspecting a blood clot sensitive but not specific (lots of false positives)

Question 34

joint aspirate (what is it, what can it help diagnose)

Answer 34

diagnostic and therapeutic way to evaluate synovial fluid gout, septic arthritis, RA

Question 35

DEXA scan

Answer 35

determines bone mineral density helps determine when to start pharmacologic tx for osteoporosis

Question 36

what is measured in a DEXA scan

Answer 36

hip and lumbar spine

Question 37

what age do you have to be to get a DEXA scan

Answer 37

women - 65 or 10 years post menopause men - 70 or if risk factors/significant loss of height

Question 38

reccommended repeat screening for DEXA

Answer 38

normal - q 10-15y osteopenia - q 3-5y osteoporosis - q 2y

Question 39

T scores for normal, osteopenia, and osteoporosis

Answer 39

normal = -1+ osteopenia = -1 to -2.5 osteoporosis = less than -2.5

Question 40

what affects WBC besides infection and inflammation

Answer 40

chemo, HIV