Tests for arthritis/autoimmune diseases

Question 1

an immunoglobulin that is ABNORMALLY directed against IgG antibodies

Answer 1

rheumatoid factor

Question 2

the RF measured in most labs is ____

Answer 2

IgM

Question 3

RF is most commonly associated with _____ (but is not specific for this disease)

Answer 3

rheumatoid arthritis

Question 4

RF is also present in healthy individuals

T/F

Answer 4

true

Question 5

Older or younger people have more RF?

Answer 5

RF increases as we age

Question 6

RF can also be present in nonrheumatic diseases. Name 3

Answer 6

bacterial endocarditis
hepatitis
parasites
viral infection
cirrhosis
malignancy

Question 7

a heterogeneous group of autoantibodies directed against nucleic acids and nucleoproteins, e.g. DNA, histones

Answer 7

Antinuclear antibodies (ANA)

Question 8

When is ANA test indicated?

Answer 8

When patient has a clinical syndrome suggesting systemic lupus erythematosus (SLE) or other connective tissue disease

Question 9

negative ANA test excludes ____

Answer 9

systemic lupus erythematosus (SLE)

Question 10

What are two different tests that measure acute phase reactants?

Answer 10

ESR

C-reactive protein

Question 11

To perform this test, place anticoagulated blood in a vertical tube and measure the rate of fall of erythrocytes in mm/hr

Answer 11

ESR, erythrocyte sedimentation rate

Question 12

In response to a stimulus such as injury or infection, this can increase up to 1000 times its baseline concentration

Answer 12

C-reactive protein

Question 13

factors unrelated to inflammation that may result in an increased ESR

Answer 13

obesity
increasing age
drugs

Question 14

two rheumatic diseases that are almost always associated with an elevated Westergren ESR

Answer 14

polymyalgia rheumatica

giant cell arteritis (temporal arteritis)

Question 15

use of ESR in rheumatic disease?

Answer 15

assess therapy/treatment effectiveness

Question 16

this antigen is present in 95% of people with ankylosing spondylitis

Answer 16

HLA-B27

Question 17

HLA-B27 may be ordered to confirm a diagnosis of ____, ____, or ____

Answer 17

ankylosing spondylitis
Reiter syndrome
anterior uveitis

Question 18

an ultrafiltrate of plasma to which synovial cells add hyaluronate

Answer 18

synovial joint fluid

Question 19

normal synovial fluid does not clot because:

Answer 19

because fibrinogen and clotting factors don’t enter the joint space from the vascular space

Question 20

Arthrocentesis is indicated for diagnosis when one of the following three conditions is suspected:

Answer 20

1. septic arthritis
2. hemarthrosis
3. crystal-induced arthritis

Question 21

synovial fluid is analyzed for the following 8 characteristics:

Answer 21

viscosity
color
clarity
WBC count
PMN
culture
glucose
protein

Question 22

synovial fluid is reported from the lab as one of these 4 things

Answer 22

normal
non-inflammatory
inflammatory
septic

Question 23

opaque synovial fluid =

Answer 23

septic

Question 24

inflammatory synovial fluid = (color)

Answer 24

yellow

Question 25

inflammatory synovial fluid = (this viscosity)

Answer 25

low (normal is high)

Question 26

normal synovial fluid = (glucose level as compared to blood)

Answer 26

about the same as blood

Question 27

inflammatory or septic synovial fluid = (glucose level as compared to blood)

Answer 27

LOWER!!

inflammatory glucose level is lower than blood, septic is MUCH lower than blood

Question 28

protein level of inflammatory or septic synovial fluid is (lower, higher) than that of normal synovial fluid

Answer 28

HIGHER protein in synovial fluid if inflammatory or septic

Question 29

WBC count for normal, inflammatory, and septic synovial fluid

Answer 29

normal: < 200
inflammatory: 3,000 - 50,000
septic: > 50,000
(above is from lab book)

Question 30

PMNs for normal, inflammatory, and septic synovial fluid

Answer 30

normal: < 25%
inflammatory: > 50%
septic: > 75%

Question 31

ANCA testing is for what diseases?

Answer 31

vasculitic disease!

e.g. Wegener granulomatosis

Question 32

Normal synovial fluid will have firm, stable clot (hyaluronic, not blood) formation within minutes. What are the mucin clot test results for inflammatory and septic fluid?

Answer 32

inflammatory: variable
septic: friable

Question 33

contraindications for arthrocentesis:

Answer 33

main contraindication for arthrocentesis: overlying skin lesion or infection

others: coagulopathy, joint prosthesis