Wk 7: Rheumatology

Question 1

Rheumatology
1) Define it
2) What does it include? How many conditions?

Answer 1

1) Subspecialty focused on diagnosis and treatment of medical diseases of the joints, muscles, and connective tissues
2) A wide spectrum of disorders related to the musculoskeletal system, including systemic inflammatory and autoimmune diseases that may also involve other organ systems
-Over 200 conditions

Question 2

The rheumatology autoimmune component focuses on what?

Answer 2

Especially joints and connective tissues

Question 3

Give 4 examples of conditions studied by rheumatology

Answer 3

1) Rheumatoid Arthritis
2) Systemic lupus erythematosus (SLE)
3) Fibromyalgia
4) Chronic pain syndromes

Question 4

List 5 rheumatology labs

Answer 4

1) CBC
2) Urinalysis and creatinine
3) Creatine phosphokinase (CPK/CK)
4) Erythrocyte sedimentation rate (ESR)
5) C-Reactive Protein (CRP)

Question 5

CBC:
1) When may WBCs be increased?
2) When may WBCs be decreased?

Answer 5

1) In conditions where immune system is attacking itself (inflammation)
2) If they are being attacked (WBC destruction)

Question 6

Urinalysis and creatinine:
1) Protein and blood are seen in urine when ______________ affects kidneys
2) These can also show decreased __________ function

Answer 6

1) vasculitis affects kidneys
2) kidney

Question 7

Creatine phosphokinase (CPK/CK) is increased when ______________ are attacked (such as polymyositis)

Answer 7

muscles

Question 8

Erythrocyte sedimentation rate (ESR):
1) What increases it?
2) What are RBC rouleaux (singular: rouleau)?

Answer 8

1) Inflammation > increased proteins in plasma (increased viscosity) > RBCs stack up and settle faster (heavier) = increased ESR
2) Stacks of RBCs

Question 9

Name a highly sensitive positive acute phase reactant

Answer 9

C-Reactive Protein (CRP)

Question 10

1) Acute phase reactants were first discovered thanks to discovery of CRP in _____________ patients.
2) “Acute phase response” accompanies what inflammatory states, acute or chronic? Define this phrase as well.

Answer 10

1) pneumonia
2) Accompanies acute and chronic inflammatory states; adaptive changes in concentration of certain plasma proteins

Question 11

Acute phase response:
1) What is it associated with? Give examples
2) When may less significant changes occur?
3) What is the specific benefit/ function of an acute phase reactant?

Answer 11

1) Wide variety of disorders, including: infection, trauma, infarction, inflammatory arthritides, other systemic autoimmune and inflammatory diseases, and various neoplasms
2) During metabolic stress
3) Varies according to acute phase reactant

Question 12

Define acute phase reactants

Answer 12

Proteins whose serum concentrations increase or decrease by at least 25% during inflammatory states

Question 13

1) Define positive acute phase reactant
-Give examples
2) Define negative acute phase reactant
-Give examples

Answer 13

1) Positive: plasma concentration increases by at least 25%
-ESR (indirect APR; reflects plasma viscosity and presence of acute phase proteins), CRP, fibrinogen, haptoglobin, hepcidin, ferritin, procalcitonin
2) Negative: plasma concentration decreases by at least 25%
-Albumin, transferrin, antithrombin

Question 14

RA (rheumatoid arthritis):
1) Define it
2) What kind of disease is it, local or systemic?

Answer 14

1) Chronic inflammatory disease characterized by symmetric polyarthritis
2) Systemic disease that may have extraarticular manifestations

Question 15

RA (rheumatoid arthritis) labs:
1) RF and Anti-CCP antibodies are positive in _____-_____% with est. RA.
2) Antinuclear antibodies (~____%). and anemia of chronic disease may be seen.
3) __________ and __________ may be elevated; ________ may be normal, slightly elevated, or low.
4) Platelet count is often ________ and joint fluid exam consistent with inflammatory arthritis.

Answer 15

1) 70-80%
Other lab abnormalities may include:
2) (~20%)
3) SR and CRP; WBC
4) high

Question 16

1) Antibodies directed against the Fc portion of IgG are called what?
2) Which of these is the most commonly measured?
3) What is the reference value for these?

Answer 16

1) Rheumatoid Factors (RFs)
2) IgM RF
3) Negative (or “very low”)

Question 17

1) In Rheumatoid Arthritis, RFs react to abnormal synovial IgGs, which are produced from _______________ in joint synovial membranes and act as ____________.
2) What do RFs form when they react with these IgGs? What do these do?

Answer 17

1) lymphocytes; antigens
2) Immune complexes; activate the complement system and cause inflammation > joint damage
-can also damage other tissues (lung, heart, nerves, vessels, etc.)

Question 18

Immune complexes that activate the complement system and cause inflammation joint damage may be formed by what?

Answer 18

RFs (rheumatoid factors) reacting to abnormal synovial IgGs

Question 19

RF for diagnosis of RA: Describe the specificity

Answer 19

1) Lacks specificity for RA (false positives)
a) Found in other chronic inflammatory diseases (SLE, Sjögren’s, etc.) and chronic infections (Hep. B/C, syphilis, TB, etc.) and may be falsely positive in the elderly
b) The higher the RF level, the more likely it is to be due to RA

Question 20

RF for diagnosis of RA: Describe the sensitivity

Answer 20

1) Limited sensitivity (false negatives)
a) Serum IgM RF present in ~75% of patients with RA
b) Sensitivity of only 50% in early disease
2) Negative RF value does not exclude RA

Question 21

RF value is a It is a poor RA screening test for who?

Answer 21

The asymptomatic general population
(use in the appropriate clinical context and in conjunction with other findings)

Question 22

Anti-Cyclic Citrullinated Peptide (anti-CCP) Antibody
(aka, CCP-IgG, anticitrullinated protein antibody (ACPA))
1) Define Citrullination. What is it a part of?
2) When does this process increase?
3) Sometimes citrullination alters peptide shape enough that the body thinks it is an antigen; what happens in that cause?

Answer 22

1) Posttranslational modification of protein, conversion of AA arginine to citrulline; part of apoptosis
2) During inflammation
3) Anti-CCP antibody is an IgG antibody that attacks citrullinated peptide antigens

Question 23

Anti-CCP Antibodies for diagnosis of RA:
1) Sensitivity?
2) Specificity?
3) Is this always a solo test?

Answer 23

1) Sensitivity similar to RF
2) The most specific blood test for RA (specificity ~95%):
positive test helps rule in RA
3) Often done alongside RF

Question 24

Systemic Lupus Erythematosus (SLE):
1) What is it? What organ does it affect?
2) Immunologic abnormalities, especially the production of ____________________, are a prominent feature.
3) Describe the variation of clinical features

Answer 24

1) Chronic autoimmune disease of unknown cause; can affect virtually any organ
2) antinuclear antibodies (ANΑ)
3) Range from mild joint and skin involvement to life-threatening kidney, hematologic, or central nervous system involvement

Question 25

SLE 1) What are the sensitivity and specificity of ANA (generic)? 2) What about for specific types of ANAs, like antibodies to double-stranded DNA **(anti-dsDNA)** and to Smith **(anti-Sm)**?

Answer 25

1) Very sensitive but not specific 2) **Specific** (but not sensitive)

Question 26

SLE: Besides ANAs, what other lab values may be abnormal?

Answer 26

1) Depressed serum complement (flares) 2) Other autoantibodies 3) **Elevated ESR +/- CRP (flares)** 4) Anemia, leukopenia, thrombocytopenia

Question 27

1) What are ANAs? 2) How can they be tested? 3) What is the normal range?

Answer 27

1) Diverse group of autoantibodies that target nuclear and cytoplasmic antigens 2) Generically or specifically for one of many subtypes using ANA panel 3) Negative

Question 28

Antinuclear Antibodies (ANAs) are especially important for ________________________

Answer 28

systemic lupus erythematosus (SLE)