Lab Testing In Rheumatic Dx

Question 1

What are the non-specific acute phase reactants?

Answer 1

ESR (erythrocyte sedimentation rate): rise w/ age, monitor dx activity (PMR, GCA)

CRP (c-reactive protein): synthesized in liver, monitor dx activity, pro-inflammatory cytokines inc CRP, CRP activates complement > phagocytosis

Question 2

What CRP value represents an inflammatory process? Does this value fluctuate faster or less than ESR?

Answer 2

> 8 mg/L

More

Question 3

Are serologies an appropriate single definitive diagnostic tool?

Answer 3

No

Question 4

What is Rheumatoid Factor? What produces it?

Answer 4

Auto-antibody (IgM) that targets Fc portion of IgG

B-cells in synovial joints of RA pts

Question 5

Is RF found in healthy people? Is it always found in sick people?

Answer 5

Yes

No

Question 6

What’s the significance of the RF level?

Answer 6

High levels associated w/ more aggressive dx and worse prognosis

Question 7

What lab result gives a 99.5% specificity for RA?

Answer 7

Pos anti-CCP + Pos RF

Question 8

Whats does anti-CCP target? What does it signal?

Answer 8

Citrullinated proteins

Aggressive and erosive dx

Question 9

Which test alone is most specific for RA?

Answer 9

Anti-CCP (more-so than RF)

Question 10

What marker is 99% indicative of SLE?

Answer 10

Anti-SM antibodies in an ANA

Question 11

What is a rim pattern ANA associated w/?

Answer 11

Anti-DS DNA in Lupus

Question 12

What hematologic results would you expect in a pt being worked up for SLE?

Answer 12

Hemolytic anemia w/ reticulocytosis (lots of young/immature RBCs)

Leukopenia

Lymphopenia

Throbocytopenia

Question 13

Is ANA (anti-nuclear antibody) found in normal healthy pts?

Answer 13

Yes, 30% of the time

Question 14

What test comes up as a false positive in SLE?

Answer 14

RPR (test for syphilis)

Question 15

What lab is used to support a streptococcal infection?

Answer 15

ASO titer (antistreptolysin O antibody)
- group A strep infection

Question 16

What is rheumatic fever?

Answer 16

Rheumatic fever is a reaction to the group A strep infection

Question 17

What are the Jones criteria?

Answer 17

Sxs of rheumatic fever

Carditis
Joint inflammation (arthritis)
Chorea (involuntary purposeless movements)
Sub-Q nodules
Erythema marginatum (rash)

Question 18

Does a strep infection cause arthritis? If so, where?

Answer 18

It can, part of rheumatic fever response

Asymmetrically in large joints (knees, hips, elbows, ankles)

Question 19

Difference between RA vs strep infection?

Answer 19

RA = symmetrical joint involvement

Strep infection = asymmetrical joint involvement

Question 20

What uric acid level is a factor in gout attacks?

Answer 20

Uric acid (urate) > 6.8 mg/dl

Question 21

Gout is due to in part..?

Answer 21

Under excretion (kidney dx) or over-production (alcohol, food) of uric acid

Question 22

Where and when do gout attacks often occur?

Answer 22

1st MTP joint of the foot at night

Question 23

What’s the state of a gouty joint?

Answer 23

Hot, swollen, tender, dusky/red

Question 24

What are tophi?

Answer 24

Associated w/ gout, nodular deposits of monosodium urate crystals in the skin

Question 25

Number of joints involved terminology includes:

Answer 25

``` Mono arthritis (one joint) Oligo arthritis (2-3) Pauci arthritis (4-5) Poly arthritis (6 or more) ```

Question 26

In regards to inflammation, what are the cardinal signs?

Answer 26

Pain, swelling, redness, heat, tenderness, stiffness

Question 27

What's the involvement of distal interphalangial joints in RA vs OA?

Answer 27

``` RA = not involved OA = involved ```

Question 28

What is the swan neck deformity and what's it associated w/? Boutonniere?

Answer 28

Both involved w/ RA Swan: flexion of DIPJ (swans head), extension of PIPJ Boutonniere is the opposite

Question 29

What Bowel dxs are associated w/ arthritis?

Answer 29

IBD: - ulcerative colitis - chrohn's dx - Behcet's Bowel infection > reactive arthritis

Question 30

What's a Charcot's joint associated w/? What is it?

Answer 30

DM Painless joint d/t excessive n dmg by DM

Question 31

What's Cheiroarthropathy and what is it associated w/?

Answer 31

Hands are stiff and skin on hands are thick DM

Question 32

What's Carpal/Tarsal tunnel syndrome associated w/ regarding arthritic pairings?

Answer 32

Thyroid dx

Question 33

Xerophthalmia is associated w/ what dxs regarding arthritis?

Answer 33

Sjogren's | Sarcoid

Question 34

What are cytoid bodies and when are they seen?

Answer 34

White lesions of the retina SLE

Question 35

Rim patterned DNA =

Answer 35

ANA result of Anti-DS DNA

Question 36

What are the possible results of a joint analysis?

Answer 36

Normal fluid (clear, <200 cells) Non-inflammatory (200-2000 cells) Inflammatory (2000-50000, cloudy) Septic (>50000, cloudy)