Rheumatoid arthritis

Question 1

Genes which predispose an individual to RA are found in which region of the DNA?

Answer 1

HLA DR4

Question 2

What is the definition of RA?

Answer 2

Rheumatoid arthritis is a multi-systemic, chronic, autoimmune inflammatory condition characterised by a symmetrical polyarthropathy which can result in significant loss of function.

Question 3

What is the prevalence of RA?

Answer 3

~ 1%

Question 4

What is the aetiology of RA?

Answer 4

The aetiology of RA is multifactorial with both genetic and environmental influences. HLA-DR4 is a genetic marker of prevalence and severity and it is known that there is an increased risk of RA development in smokers, who also tend to have more aggressive disease

Question 5

Which WBC has a key role in the initiation of inflammation in RA?

Answer 5

T-lymphocytes appear to be the key effector cell. T-cells orchestrate the immune response through a host of cytokines.

Question 6

How do macrophages contribute to the pathophysiological changes in RA?

Answer 6

Activated macrophages produce cytokines (intercellular messenger proteins) such as TNF-α and IL-1 which:

• stimulate inflammation
• attract other immune cells
• cause excess synovial fluid production
• cause cartilage destruction
• cause bone resorption

Question 7

How do B-cells contribute to the pathophysiology of RA?

Answer 7

Activated B-cells in the synovium produce:

• rheumatoid factor &
• anticitrullinated protein antibodies

*NB, anti-CCP levels in the serum are used to detect these antibodies

Question 8

What % of patients with RA test +ve for RF and anti CCP?

Answer 8

80%

Question 9

High levels of RF and anti CCP are assoc. w/ ?

Answer 9

More severe disease and the presence of extra articular features

Question 10

What % of patients with RA test +ve for RF and anti CCP?

Answer 10

80%

Question 11

High levels of RF and anti CCP are assoc. w/ ?

Answer 11

More severe disease and the presence of extra articular features

Question 12

Define synovitis

Answer 12

Inflammation and swelling of the synovial membrane

Question 13

Macrophages and osteoclasts create chronically inflamed fibrous tissue known as?

Answer 13

Pannus

Question 14

When is the peak age of onset for RA?

Answer 14

Fourth and fifth decades of life

Question 15

How long do symptoms generally take to develop?

Answer 15

Weeks to months

Question 16

What are the four main articular features of RA?

Answer 16

Joint pain, stiffness, swelling and loss of function

Question 17

Which joints does RA usually target?

Answer 17

Small and medium joints (but can affect any) **in a symmetrical fashion

Question 18

An atypical presentation of RA where there is an acute onset of symptoms affecting usually one (monarthritis) or multiple joints can occur. What is this known as?

Answer 18

Palindromic RA

Question 19

What is the cause of “boggy swelling” in RA?

Answer 19

Synovitis

Question 20

Today, RA should be identified prior to deformity and urgent referral for treatment should be within how many weeks of symptoms onset?

Answer 20

6 weeks

Question 21

The wrists and which joints of the hand are usually affected in RA?

Answer 21

The MCP and PIP joints are usually affected. (There is sparing of the DIP joints).

Question 22

Subluxation of the MCP joints occurs in RA. This causes the proximal phalanges to drift in which direction?

Answer 22

Ulnar and volar (palmar surface) direction

Question 23

Name the two common deformities that occur in the digits of the hand

Answer 23

Boutonnières and swan-neck deformities

Question 24

Describe boutonnière deformity

Answer 24

PIP flexion; DIP hyperextension.

Question 25

Describe swan-neck deformity

Answer 25

DIP flexion; PIP hyperextension

Question 26

In which direction does the wrist deviate in RA?

Answer 26

Radial deviation

Question 27

What happens to the proximal phalanges of the feet in RA?

Answer 27

They sublux dorsally

Question 28

What happens to the metatarsal heads in RA?

Answer 28

They become eroded and displace towards the floor (they can be easily palpated through the sole of the foot and make weight bearing really uncomfortable).

Question 29

What can happens to the cervical spine in RA? What pain results?

Answer 29

Atlanto-axial subluxation which causes neck pain that radiates to the occiput.
(*NB, Atlas=C1; Axis=C2)

Question 30

Name four extra-articular features of RA

Answer 30

1) Rheumatoid nodules
2) Tenosynovitis
3) Bursitis
4) Carpal tunnel syndrome

Question 31

Where do rheumatoid nodules tend to develop?

Answer 31

In areas affected by pressure friction, such as the fingers, elbows and Achilles tendon.

(They are seen in patients who test +ve for RF and are commoner in smokers)

Question 32

Which nerve is compressed in carpal tunnel syndrome?

Answer 32

Median nerve

Question 33

Why is atlanto-axial subluxation a red flag complication that should be actively looked for as part of pre-surgical evaluation?

Answer 33

If not picked up, atlanto-axial subluxation can lead to sudden death, especially if patients undergo neck manipulation for endotracheal intubation during surgical procedures.

Question 34

What’s the triad chracterizing Felty’s syndrome?

Answer 34

RA, splenomegaly and neutropenia