The science of rheumatoid arthritis

Question 1

What happens to the joint in rheumatoid arthritis

Answer 1

Inflammation of the synovium due to inflammation - synovitis

The synovitis leads to the erosive damage of the bone and cartilage - on Xray the erosive damage is seen as marginal erosions

Question 2

What is the definition of rheumatoid arthritis

Answer 2

Chronic, symmetric, polyarticular (5 or more joints) inflammatory joint disease that affects the small hands of the hands and feet

Question 3

What is the rheumatoid synovitis characterised by

Answer 3

inflammatory cell infiltration - fibroblast proliferation and neoangiogenesis - development of new blood vessels

Question 4

What does the synovial fluid in the joint cavity contain - especially in acute cases of rheumatoid arthritis

Answer 4

neutrophils

Question 5

What antibodies are associated with rheumatoid arthritis

Answer 5

RFs - rheumatoid factors - and anti-citrullinated protein antibodies

Question 6

Which antibodies are checked on suspected rheumatoid arthritis

Answer 6

Rheumatoid factor and anti-CCP antibodies

Question 7

What is seropositive arthritis

Answer 7

they test positive for either rheumatoid factor or anti-CCP antibodies

Question 8

What is seronegative rheumatoid arthritis

Answer 8

Testing negative for rheumatoid factor or anti-CCP antibodies - has a better prognosis

Question 9

What gene is rheumatoid arthritis associated with

Answer 9

HLA-DRB1 locus

Question 10

What enviromental factors can cause rheumatoid arthritis

Answer 10

smoking and bronchial stress - e.g exposure to silica

Infectious agents like viruses

Question 11

What is citrullination

Answer 11

Conversion of amino acid arginine into the amino acid citrulline

Question 12

How does citrillation lead to rheumatoid arthritis

Answer 12

When there is excessive citrullation, antigens form that can cause the formation of autoantibodies

Question 13

What happens in synovitis in rheumatoid arthritis

Answer 13

Intimal lining hyperplasia and sublining infiltration of mononuclear cells - mainly immune and inflammatory cells
Macrophages in the lining are then activated
Fibroblasts proliferate
Synovial B cells produce antibodies
Dendritic cells present anigens to T cells in synovial germinal centres
Hypoxic conditions and cytokines cause new blood vessels to form (neoangiogenesis)
Cells are trapped in the joint and cannot leave
Neutrophils are present in the synovial fluid

Question 14

What is the role of Chemokines in rheumatoid arthritis

Answer 14

Recruitment of inflammatory cells into the joint

Question 15

What produces chemokines

Answer 15

macrophages and fibroblasts

Question 16

What can inflammatory cytokines do

Answer 16

recruitment of inflammatory cells into a joint

Activates fibroblasts, chondrocytes and osteoclasts
promotes angiotensin

Surpasses T regs

Question 17

What is responsible for cartilage damage in rheumatoid arthritis

Answer 17

proteases (metalloproteinases and aggrecanases) which are produced by pathogenic synovial fibroblasts

Question 18

What causes bone destruction

Answer 18

mediated by osteoclasts that are activated under the influence of RNAKL which is produced by the synovium

Question 19

What are the key cytokines in rheumatoid arthritis

Answer 19

TNF alpha
IL-1
IL-2
RANk - Ligan IL-17