Labs in Rheum

Question 1

CRP

Answer 1

C reactive protein
Synthesized by liver in inflammatory/infectious states
Rises/falls quickly
Not affected by age or gender

Question 2

If ESR and CRP both elevated…

Answer 2

Infection, inflammatory states

(RA, vasculitis, psoriatic arthritis), trauma, cancer

Question 3

Elevated ESR but normal CRP…

Answer 3

Conditions w elevated immunoglobulins

SLE, myloma, liver dz, sjorgens

Question 4

Rheumatoid factor

Answer 4

IgM antibody directed against IgG
Present in 80% patients w RA
also present in…
Hepatitis C, Sjorgens, chronic infections (TB)

Question 5

Anti CCP antibody

Answer 5

More specific for RA (95%) than rfactor

If pos…mor aggressive erosive dz

Question 6

ANA

Answer 6

Anti nuclear antibody
IgG antibody against nuclear antigens
*immunofluorescence detects patten
FALSE POSITIVES COMMON..10-20% females

Question 7

Diffuse/homogenous ANA pattern

Answer 7

SLE
Drug induce lupus

**normal in low levels

Question 8

Peripheral ANA pattern

Answer 8

SLE

Question 9

Speckled ANA pattern

Answer 9

SLE
MCTD
Sjorgens

Question 10

Nucleolar ANA pattern

Answer 10

Scleroderma

SLE

Question 11

Centromere ANA pattern

Answer 11

CREST syndrome

Question 12

SCL-70 ANA pattern

Answer 12

Scleroderma

Question 13

ANCA

Answer 13

Anti-neutrophil cytoplasmic antibody
Autoantibodies that recognize proteins w in neutrophils
associated w vasculitis***

Question 14

P-ANCA vs C-ANCA

Answer 14

Perinuclear staining vs cytoplasmic staining

Question 15

ESR

Answer 15

Sedimentation rate
*the rate at which RBC fall in a standardized tube in 1 hour
Increased w age, females, adipose tissue

Can take days to increase/decrease