Rheumatology 1

Question 1

what is rheumatoid arthritis?

Answer 1

chronic autoimmune disorder that typically involves inflammation of the synovium of typical joints progressing to articular cartilage destruction

Question 2

what are the pathogenesis factors of RA?

Answer 2

• CTLA-4
• HLA DR1
• PTPN-22
• Environmental factors

Question 3

what is the PTPN-22 mutation?

Answer 3

gain-of-function mutation in a tyrosine phosphatase that is hypothesized to result in the abnormal thymic selection of autoreactive T and B cells

Question 4

what are some environmental factors for RA?

Answer 4

• smoking
• some infections play a role in the development of RA

Question 5

what releases inflammatory mediators that stimulate other inflammatory cells leading to tissue injury?

Answer 5

CD4+ T-cells

Question 6

what are the key inflammatory cytokines involved in RA?

Answer 6

• INF-y
• IL-17
• TNF-a and IL-1
• RANKL

Question 7

what are RANKL

Answer 7

it is expressed on activated T cells (especially Th17 cells) stimulates bone resorption

Question 8

what is a significant antibody that recognizes self-antigen in RA?

Answer 8

anti-CCP (anti-citrullinated peptide)

Question 9

in RA, IgM and IgA auto-antibodies that bind IgG Fc Region, collectively referred to as ?

Answer 9

rheumatoid factor

Question 10

how is citrulline made?

Answer 10

within a protein arginine amino acids can be converted to citrulline

Question 11

what is associated with anti-citrulline antibody?

Answer 11

HLA-DR4

Question 12

What triggers the induction of costimulators on antigen-presenting cells (APCs)?

Answer 12

A microbe activates APCs by engaging pattern recognition receptors (PRRs), leading to expression of costimulatory molecules like B7.

Question 13

In autoimmune reactions, What happens when APCs present self-antigens along with costimulatory signals?

Answer 13

Instead of inducing tolerance, costimulatory molecules override tolerance and activate self-reactive T cells.

Question 14

What is the outcome of T-cell activation by self-antigens with costimulation?

Answer 14

Activated T cells attack self-tissues, resulting in autoimmune reactions.

Question 15

What is molecular mimicry in the context of autoimmunity?

Answer 15

It’s when a microbial antigen structurally resembles a self-antigen, causing the immune system to target both.

Question 16

How does molecular mimicry lead to autoimmunity?

Answer 16

T cells activated by microbial antigens also recognize similar self-antigens, leading to self-tissue attack.

Question 17

What role do PRRs play in molecular mimicry?

Answer 17

PRRs triggered by infection cause APCs to express costimulatory molecules, enabling T-cell activation instead of anergy.

Question 18

Which autoimmune disorders are associated with molecular mimicry?

Answer 18

Rheumatoid arthritis and rheumatic fever.

Question 19

What activates macrophages in rheumatoid arthritis (RA)?

Answer 19

Cytokines from Th17 and Th1 cells.

Question 20

What is the result of macrophage activation in RA?

Answer 20

Secretion of pro-inflammatory and pro-repair cytokines, contributing to pannus formation.

Question 21

in RA, what is the most common joints affected?

Answer 21

the small joints of the hands and feet (MCPs and PIPs joints)

Question 22

what is the second most common joints affected in RA?

Answer 22

wrist, ankles, elbows, knees

Question 23

what is a characteristic morphologic feature within the joint for RA?

Answer 23

formation of a pannus

Question 24

what is a pannus?

Answer 24

mass of edematous synovium, inflammatory cells, granulation tissue, and fibroblast growth causing articular cartilage erosion

Question 25

what happens when pannus migrate over the cartilage surface + recruitment of leukocytes into synovial space?

Answer 25

loss of cartilage and joint function

Question 26

Over time, after articular cartilage destruction, pannus forms a "bridge" between apposing bones forming a ?

Answer 26

fibrous ankylosis

Question 27

what is ankylosis?

Answer 27

a "bridge" across a joint that limits range of motion

Question 28

is RA symmetrical or asymmetrical distribution?

Answer 28

symmetrical distribution

Question 29

In general, RA is suggested when many small joints and a few large typical joints are affected in a

Answer 29

symmetrical fashion

Question 30

in RA, Inflammatory joint pain often exhibits

Answer 30

"gelling" or morning stiffness

Question 31

what is "gelling" or morning stiffness

Answer 31

Severe stiffness and pain of the joint after it has been inactive for prolonged periods of time (ie. sleep)

Question 32

"inflammatory" morning stiffness typically lasts ?

Answer 32

greater than one hour

Question 33

for RA, Inflammation in tendons, ligaments, and even adjacent skeletal muscle results in characteristic wrist signs:

Answer 33

- radial deviation of the wrist - ulnar deviation of the fingers - flexion-hyperextension abnormalities of the fingers (swan neck, boutonniere)

Question 34

swan neck deformity is due to what?

Answer 34

the intrinsic hand muscle contracture

Question 35

in swan neck deformity, the PIPs are ? and DIPs are ?

Answer 35

hyperextended flexed

Question 36

boutonniere is due to ?

Answer 36

ruptures of the central slip of the extensor tendons

Question 37

in boutonniere deformity, the PIPs are ? and DIPs are ?

Answer 37

flexed hyperextended

Question 38

what is the radiographic hallmark of RA?

Answer 38

juxta-articular osteopenia and bone erosions

Question 39

what does juxta-articular osteopenia mean?

Answer 39

The bones near the joints look thinner or weaker than normal

Question 40

what does bone erosions mean?

Answer 40

Parts of the bone near the joint appear damaged or "eaten away."

Question 41

what is the most common skin lesion in RA?

Answer 41

rheumatoid nodules

Question 42

rheumatoid nodules arise in regions subject to ?

Answer 42

pressure

Question 43

what are the laboratory contributions that indicate RA?

Answer 43

- positive rheumatoid factor - positive anti-citrulline antibodies - elevated C-reactive protein (CRP)

Question 44

what is juvenile idiopathic arthritis

Answer 44

arthritis occur prior to age 16 years and persist for at least 6 weeks, no clear explanation why

Question 45

what are the types of juvenile idiopathic arthritis?

Answer 45

- systemic arthritis - oligoarthritis - rheumatoid-factor positive arthritis - enthesitis-related arthropathy

Question 46

what is oligoarthritis?

Answer 46

arthritis affecting four or fewer joints during the first 6 months of disease in the absence of psoriasis and an HLA-B27 genotype defines the oligoarthritis variant

Question 47

what is Rheumatoid-factor positive poly arthritis?

Answer 47

Similar to adult RA, usually found in teenage girls

Question 48

what is Enthesitis-related arthropathy

Answer 48

Primarily found in younger males HLA-B27 positive, tends to affect joints of lower limbs and insertions of tendons

Question 49

what characterizes OA?

Answer 49

Characterized by articular cartilage degeneration resulting in structural and functional synovial joint failure

Question 50

OA can be ? or ?

Answer 50

primary or secondary

Question 51

what is primary OA?

Answer 51

insidious onset without apparent initiating cause; considered an aging phenomenon

Question 52

what is secondary OA?

Answer 52

occurs in younger populations secondary to joint deformity, prior injury, or underlying systemic disease that places joints at risk

Question 53

what is the most common joint disease?

Answer 53

OA

Question 54

Late OA is characterized by ?

Answer 54

chondrocyte loss and severe matrix degradation

Question 55

OA is typically less ? than RA with a predilection for ?

Answer 55

symmetrical larger joints

Question 56

what is Heberden's nodes?

Answer 56

osteophyte formations at the DIPs

Question 57

Bouchard's nodes are found at the ?

Answer 57

PIPs

Question 58

what are the types of infectious arthritis?

Answer 58

- suppurative - mycobacterial - lyme - viral

Question 59

what is suppurative infectious arthritis?

Answer 59

Bacterial infection entering joints from distant sites via hematogenous spread

Question 60

what are the risk factors of suppurative infectious arthritis?

Answer 60

Individuals with deficiencies in complement factors C5 - C9 - Inability to form membrane attack complex (MAC) Immunodeficiencies, joint trauma, chronic arthritis, & IV drug use

Question 61

for mycobacterial infectious arthritis, chronic progressive monoarticular infections caused by ?

Answer 61

M. tuberculosis

Question 62

lyme infectious arthritis is caused by ?

Answer 62

spirochete, Borrelia burgdorferi

Question 63

if lyme infectious arthritis is left untrated, up to 80% of patients will develop a ? lasting weeks to months

Answer 63

migratory arthritis