Antiphospholipid syndrome: arterial/venous thrombosis, miscarriage, livedo reticularis
Thrombocytopenia is associated with antiphospholipid syndrome
Antiphospholipid syndrome is an acquired disorder characterised by a predisposition to both venous and arterial thromboses, recurrent fetal loss and thrombocytopenia.
It may occur as a primary disorder or secondary to other conditions, most commonly systemic lupus erythematosus (SLE)
A key point for the exam is to appreciate that antiphospholipid syndrome causes a paradoxical rise in the APTT. This is due to an ex-vivo reaction of the lupus anticoagulant autoantibodies with phospholipids involved in the coagulation cascade
Risk factor for thrombosis Lupus anticoagulant is the greatest predictor of future thrombosis in patients with antiphospholipid syndrome
antiphospholipid antibody syndrome (APAS) can be diagnosed if:
the patient has anticardiolipin antibodies, or lupus anticoagulant on two occasions, over a period of 12 weeks, and either:
has had a thrombus, or
a history of recurrent < 10 week pregnancy loss, or one pregnancy loss > 10 weeks in gestation when other causes of pregnancy loss have been excluded.
the most clinically important autoantibodies directed against phospholipid binding plasma proteins are:
1. The lupus anticoagulant
2. Anti-beta-2 glycoproetin I antibodies, and
3. The anticardiolipin antibodies.
Management - based on BCSH guidelines
initial venous thromboembolic events: warfarin with a target INR of 2-3 for 6 months
Other opinion: The occurrence of even a single thrombotic event in a patient with antiphospholipid syndrome warrants lifelong anticoagulation, as the risk of recurrence is 20-70%.
recurrent venous thromboembolic events: lifelong warfarin; if occurred whilst taking warfarin then increase target INR to 3-4
arterial thrombosis should be treated with lifelong warfarin with target INR 2-3
Rheumatoid arthritis: patients have an increased risk of IHD
Rheumatoid arthritis: complications
A wide variety of extra-articular complications occur in patients with rheumatoid arthritis (RA):
respiratory: pulmonary fibrosis, pleural effusion, pulmonary nodules, bronchiolitis obliterans, methotrexate pneumonitis, pleurisy
ocular: keratoconjunctivitis sicca (most common), episcleritis, scleritis, corneal ulceration, keratitis, steroid-induced cataracts, chloroquine retinopathy
ischaemic heart disease: RA carries a similar risk to type 2 diabetes mellitus
increased risk of infections
Felty's syndrome (RA + splenomegaly + low white cell count)