autoimmune rheumatic diseases

Question 1

what is an autoimmune disease

Answer 1

pathological condition caused by an immune response directed against an antigen within the host i.e. a self antigen

Question 2

what are the autoimmune rheumatic diseases (ARDs)?

Answer 2

SLE
Antiphospholipid syndrome
Systemic sclerosis
Polymyositis and dermatomyositis

Question 3

what is SLE

Answer 3

systemic lupus erythematosus

an inflammatory multi-system disease characterised by the presence of serum antibodies against nuclear components

Question 4

epidemiology SLE

Answer 4

young women (20-40yo)

Question 5

pathogenesis SLE

Answer 5

• apoptotic cells cleared inefficiently by phagocytes resulting in transfer to lymphoid tissue where they are taken up by antigen presenting cells
• these present to t cells
• stimulates b cells = autoantibodies

Question 6

Clinical manifestations of SLE

Answer 6

affects all systems !!
symmetrical small joint arthralgia & skin manifestations are common - butterfly rash on cheeks
non systemic features such as fever, malaise and depression can dominate the clinical picture

Question 7

discoid lupus

rx?

Answer 7

benign variant of SLE
only skin is involved
characteristic facial rash with erythematous plaques which progress to scarring and pigmentation
rx = topical steroids

Question 8

blood count SLE

Answer 8

normochromic normocytic anaemia w/ neutropenia, lymphopenia & thrombocytopenia
ESR raised, CRP norm

Question 9

SLE diagnostic tests

Answer 9

serum antibodies - Anti-dsDNA is specific for SLE +ve in 70%

skin/kidney biopsy

Question 10

rx SLE

Answer 10

avoid sunlight, stop smoking / other CV risks
NSAIDs + chloroquine mild disease
corticosteroids = main rx
immunosuppressives if severe

Question 11

antiphospholipid syndrome clinical features

Answer 11

THROMBOSIS and positive blood tests for antiphospholipid antibodies
thrombosis = stroke, TIA, MI, DVT, miscarriage

Question 12

antiphospholipid syndrome rx

Answer 12

LT warfarin

pregnant pts given aspirin and heparin

Question 13

systemic sclerosis (scleroderma) pathophysiology?

Answer 13

endothelial lesion and widespread vascular damage = uncontrolled and irreversible proliferation of connective tissue / thickening of vascular walls = narrowing of lumen

Question 14

types of systemic sclerosis

Answer 14

limited cutaneous scleroderma (70%) and diffuse cutaneous scleroderma (30%)

Question 15

limited cutaneous scleroderma

Answer 15

starts with Raynaud’s phenomenon many years before skin changes
later: skin thickened, fingers taper (sclerodactyly), beaking of nose, limitation of mouth opening, nodules of calcium in fingers
only affects: hands, feet, face, forearms

Question 16

CREST

Answer 16

limited cutaneous scleroderma previously called CREST
Calcinosis
Raynaud’s
Eosophageal involvement
Sclerodactyly
Telangiectasia (dilatation of the capillaries causing them to appear as small red or purple clusters)

Question 17

diffuse cutaneous scleroderma

Answer 17

skin changes rapid and more widespread than limited disease
early involvement of other organs:
GI dilatation and atony: oesophagus (heartburn), SI (bacterial overgrowth)
renal (AKI/CKI),
lung fibrosis and pulm vasc dis = HTN
myocardial fibrosis = arrythmias

Question 18

raynaud’s disease and phenomenon

rx

Answer 18

Intermittent spasm in arteries supplying fingers and toes - precipitated by cold, relieved by heat.
RD: no underlying disorder - affects young women
RP: underlying autoimmune dis, B-blocker therapy, vascular damage
rx - nifedipine

Question 19

Diagnosis scleroderma

Answer 19

clinically - skin changes

bloods - normochromic normocytic anaemia

serum autoantibodies - anti-topoisomerase and anti RNA polymerase = highly specific for pts with diffuse dis

xray = calcium deposits in hands

Question 20

management scleroderma

Answer 20

symptomatic depending on organ involvement

ACEi for HTN / to prevent further renal damage

Question 21

polymyositis and dermatomyositis (PM and DM)

Answer 21

PM - rare muscle disorder = inflammation and necrosis of skeletal muscle fibres
when skin involved it’s called DM

Question 22

clinical features polymyositis and dermatomyositis (PM and DM)

Answer 22

• symmetrical progressive muscle weakness and wasting in shoulder and pelvic girdle = difficulty squatting, going upstairs, raising hands above head
• pharyngeal / laryngeal involvement = dysphagia / resp failure
• DM = skin changes - purple eyelids, scaly erythematous plaques over knuckles

Question 23

investigations polymyositis and dermatomyositis (PM and DM)

Answer 23

muscle biopsy
serum muscle enzymes (creatine kinase, amino transferses, aldolase) = raised
anti-tRNA synthetase antibodies +ve

Question 24

management polymyositis and dermatomyositis (PM and DM)

Answer 24

oral prednisolone

immunosuppressive therapy - azathioprine, methotrexate, ciclosporin

Question 25

sjogrens syndrome

Answer 25

characterised by immunologically mediated destruction of epithelial exocrine glands, especially the lacrimal and salivary glands

Question 26

clinical features sjogrens syndrome

Answer 26

• dry eyes / dry mouth
• difficulty eating a dry biscuit
• occurs on its own or in association w other autoimmune diseases
• arthritis, raynaud’s, renal tubular defects causing diabetes insipidus, pulm fibrosis, vasculitis

Question 27

investigations sjogrens syndrome

Answer 27

serum autoantibodies - antinuclear (in 80% of pts), anti-RO and rheumatoid factor in primary sjogrens syndrome

+ve Schrimer test (filter paper placed inside lower eyelid; wetting of less than 10mm in 5 min is +ve) confirms defective tear production

Question 28

rx sjogrens syndrome

Answer 28

symptomatic
artificial tears
saliva replacement

Question 29

what is chloroquine

Answer 29

an ANTIMALARIAL