Antiphospholipid and Sjogren's syndromes

Question 1

Antiphospholipid syndrome

Answer 1

A syndrome of recurrent thrombi (venous or arterial) and/or recurrent miscarriages with positive test for antiphospholipid antibodies (aPL)
Can occur alone or in conjunction with other autoimmune conditions (lupus)

Question 2

Test for antiphospholipid antibodies (aPL)

Answer 2

Anticardiolipin test
Lupus anticoagulant test
Anti-Beta-2-glycoprotein test

Question 3

Anticardiolipin test

Answer 3

Detects IgG or IgM against cardiolipin (a negatively charged phospholipid)

Question 4

Lupus anticoagulant test

Answer 4

aPL will have an anticoagulant effect in a test tube but a procoagulant effect in the body

Question 5

Anti-Beta-2-glycoprotein test

Answer 5

detects abs against B2-glycoprotein, which interacts closely with phospholipids

Question 6

Criteria for APS

Answer 6

Positive results in two tests at least 6wks apart – but not all people who are positive will develop APS

Question 7

Pathogenesis of APS

Answer 7

Negatively charged phospholipids and B-2-glycoprotein are present of apoptic blebs –> similar mechanism as lupus
aPL binds to the N-terminus of B-2-glycoprotein on the membranes of endothium, platelets, monocytes and trophoblasts causing thombosis or miscarriage

Question 8

The main Clinical Features of APS

Answer 8

Recurrent thrombosis and miscarriage are the most common presenting symptoms
Ischemic stroke occur in 20% and DVT in 40% of pts
Can be arterial or venous (but not in the same pt)

Question 9

Treatment of patients with APS who have had 1 or more thrombus

Answer 9

Long term warfarin (used to aim for INR >3 but now thought that lower INR may be just as safe)

Question 10

APS and recurrent miscarriage

Answer 10

27% of women who have two or more miscarriages have APS

Question 11

Rarer features of APS (9)

Answer 11

Thrombocytopenia, chorea, migraine and epilepsy
Valvular heart disease, Renal impairment
Livedo reticularis
Positive Coombs test
May be involved in accelerated atheroma formation

Question 12

Management of pregnant pts with APS

Answer 12

Pregnant pts should be given aspirin and subcut heparin from early in the pregnancy – but pre-eclampsia and poor fetal growth is still common

Question 13

Management of pts with APS who have never had a clot

Answer 13

Unclear - many are put on aspirin and clopidogrel prophylatically if there is a high IgG aPL level but there are no definite guidelines
They are rarely put on warfarin

Question 14

Sjogren’s syndrome

Answer 14

A syndrome of lymphocytic infiltration of exocrine glands causing dryness (eyes, vagina, mouth & skin)
Can occur with other autoimmune disorder (secondary) or alone (primary)

Question 15

Genetic associations of sjogren’s

Answer 15

HLA B8 and DR3

Question 16

Clinical features of Sjogren’s

Answer 16

Dryness of eyes (also mouth, vagina, skin) - may have salivary and parotid gland enlargement
Can also have: arthralgia/static polyarthritis, Raynad’s, pulmonary diffusion detects/fibrosis, vasculitis or other autoimmune conditions, polyneuropathy/fits/depression

Question 17

Rare features of sjogren’s

Answer 17

Dysphagia/abnormal oesophageal motility as seen in scleroderma
Renal tubule defects causing nephrogenic diabetes insipidus or renal tubular acidosis

Question 18

Cancer risk with Sjogren’s

Answer 18

Increased incidence of non-hodgkin’s lymphoma

Question 19

Eye Tests for Sjogren’s

Answer 19

Schiermer tear test –> a strip of filter paper is placed under the lower eyelid - (15mm in 5mins
shows punctate or filamentary keratitis

Question 20

Blood tests for Sjogren’s

Answer 20

Raised immunoglobulin, circulating immune complexes and autoantibodies - Usually rheumatoid factor positive
ANA positive in 80% and anti-mitochondrial abs in 10%
Anti-Ro is positive in 60-90% of primary sjogren’s (anti-La 35-85%)

Question 21

Impact of anti-Ro in pregnancy

Answer 21

Can cross the placenta and cause congenital heart block

Question 22

Management of Sjogren’s

Answer 22

Artificial tears and saliva is usually sufficient
Hydroxychloroquine may help any fatigue and arthralgia
Corticosteroids are rarely needed but can be used to treat persistent salivary gland swelling or neuropathy

Question 23

Overlap syndromes

Answer 23

Patient shows characteristic features of more than one ARD – treatment is usually the same
Undifferentiated ARD is when patients have positive autoantibodies and some clinical features (raynaud’s and arthralgia etc) but not enough to make a clear diagnosis of any particular ARD – may progress to a clear diagnosis or remain with a consistent mild disease

Question 24

ARD

Answer 24

Autoimmune rheumatic diseases – SLE, APS, sjogren’s, scleroderma, myositis and dermatomyositis