Guest guest Posted December 22, 2003 Report Share Posted December 22, 2003 sticky blood syndrome This syndrome was first described in 1983-1986 as the association of arterial and venous thrombosis with antibodies directed against phospholipids. Originally noted as a complication in approximately 30% of patients with systemic lupus erythematosus, it is now also diagnosed in patients with thrombotic episodes and anti-phospholipid antibodies (aPL) but without clinical features of SLE - primary antiphospholipid syndrome. aetiology There is a familial association in some cases of APS. HLA studies suggest DR7, DR4 and DQw7 plus DRw53 are risk factors. The aPL antibody is targeted to the combination of cardiolipin with a plasma protein called beta-glycoprotein I. In vivo aPL has a procoagulant effect on: platelet membranes endothelium prothrombin, protein C and protein S aPL is found in the serum of 30% of patients with SLE, in this context it is termed " lupus anticoagulant " . lupus anticoagulant The lupus anticoagulant is an immunoglobulin, IgG or IgM, which binds to phospholipids and prevents coagulation reactions from taking place on the platelet surface. It is associated with arterial and venous thrombosis, and recurrent spontaneous abortions. It occurs in about 30% of patients with systemic lupus erythematosus but may be found in other autoimmune diseases, in response to drugs such as phenothiazine, and in patients with infectious diseases such as AIDS. Often, no underlying condition may be found. The LA anti-phospholipid often occurs in association with anti-cardiolipin antibodies (aCL) - 59% of patients with SLE having LA also have aCL, and 45% with SLE and aCL, also have LA. detection of lupus coagulant There is no direct test for the lupus anticoagulant (LA). Detection is based upon its inhibitory actions on coagulation. It binds to phospholipid on the platelet surface and interferes with the formation of the prothrombin activator complex. Clotting times are increased and are not corrected by the dilution with normal plasma: increased activated partial thromboplastin time increased prothrombin time There is a false positive VDRL test. Lupus anticoagulant should be suspected whenever there is a markedly prolonged PTT without clinical bleeding. In SLE, the lupus anticoagulant is usually noted in patients who present with stroke, thrombophlebitis, and renal vein or mesenteric artery thrombosis. detection of anticardiolipin antibodies The earlier VDRL test using cardiolipin as antigen is insensitive. Modern procedures use solid-phase radioimmunoassay - RIA - or enzyme linked immunoabsorbent assay - ELISA. Since 1990, reporting of results have been standardised and are expressed in terms of GPL or MPL units. The risk of thrombosis or spontaneous abortion increases with the titre of aCL and are greater with IgG antibodies than with IgM - for example, of 39 patients with IgG greater than 20 GPL units, 70% had a thrombotic event. epidemiology the diagnosis of antiphospholipid syndrome requires that a patient have recurrent clinical events (such as thromboses or fetal loss) and an antiphospholipid antibody (such as anticardiolipin antibody or lupus anticoagulant). about 50% of patients with antiphospholipid syndrome have the primary form of the disease. about 1/3 of patients with SLE have antiphospholipid antibodies but not all of those have the syndrome. in about 2% of the normal population, detectable antiphospholipid antibodies are present. In 0.2% the titre is high. the clinical course and severity of the lupus is worsened by the presence of the antiphospholipid syndrome. the annual risk of thrombosis in untreated patients is 1 in 3 per year. clinical features The clinical features are presented according to the systems affected: neurological cardiac renal endocrine dermatological haematological obstetric thrombotic neurological Thrombosis causes ischaemic damage to the brain. MRI scans show a wide range of brain infarcts - single or multiple, large or small. Repeated episodes may result in dementia. Migraine is common and may be the first symptom. Epilepsy and chorea are associated. Transverse myelopathy is a rare, but specific, association. stroke A stroke is a focal neurological deficit, secondary to a vascular lesion, that lasts for longer than 24 hours. Strokes result from: cerebral infarction (84%): secondary to thrombosis (53%); or embolus (31%) primary intracerebral haemorrhage (10%) subarachnoid haemorrhage (6%) The definition of stroke excludes transient ischaemic attacks, subdural haematomas, and infarction or haemorrhage due to infection or tumour. However, practically it is often difficult to discriminate between a small stroke and a transient ischaemic attack. transient ischaemic attacks Transient ischaemic attacks are focal CNS disturbances caused by vascular events such as microemboli and occlusion leading to ischaemia where the symptoms last less than 24 hours and there are no permanent neurological sequelae. Transient ischaemic attacks are a risk factor for subsequent stroke or myocardial infarction. Diagnosis rests critically upon the patient's history since the attacks are seldom witnessed by a physician and there are no confirmatory tests. Emboli are the major cause. haematological thrombocytopenia - 30% of patients with idiopathic thrombocytopenic purpura have aPL autoimmune haemolytic anaemia - this is a rare feature thrombocytopaenia Thrombocytopaenia is a decrease in the number of platelets in the blood - it reduces the ability of the blood to clot and is thus a bleeding diathesis. It is defined as a platelet count less than 100,000 per cubic ml. In addition, it is important to consider also the causes of apparent thrombocytopaenia - i.e. conditions where there is platelet dysfunction. Neonatal thrombocytopaenia has a modified differential diagnosis. thrombotic Venous: DVTs - these may be recurrent. In women these may appear appear to be triggered by the use of the oral contraceptive pill hepatic thrombosis - antiphospholipid syndrome is the second most common cause of antiphospholipid syndrome. retinal vein thrombosis renal vein thrombosis major vein thrombosis may involve thoracic outlet veins or the inferior vena cava Arterial thrombosis may cause ischaemia of almost any organ pulmonary hypertension Pulmonary hypertension is of two types: pulmonary artery hypertension: this results from disorders of the lung or arterial vasculature pulmonary venous hypertension: this results from disorders of the pulmonary venous drainage or of the left heart detection of lupus coagulant There is no direct test for the lupus anticoagulant (LA). Detection is based upon its inhibitory actions on coagulation. It binds to phospholipid on the platelet surface and interferes with the formation of the prothrombin activator complex. Clotting times are increased and are not corrected by the dilution with normal plasma: increased activated partial thromboplastin time increased prothrombin time There is a false positive VDRL test. Lupus anticoagulant should be suspected whenever there is a markedly prolonged PTT without clinical bleeding. In SLE, the lupus anticoagulant is usually noted in patients who present with stroke, thrombophlebitis, and renal vein or mesenteric artery thrombosis. detection of anticardiolipin antibodies The earlier VDRL test using cardiolipin as antigen is insensitive. Modern procedures use solid-phase radioimmunoassay - RIA - or enzyme linked immunoabsorbent assay - ELISA. Since 1990, reporting of results have been standardised and are expressed in terms of GPL or MPL units. The risk of thrombosis or spontaneous abortion increases with the titre of aCL and are greater with IgG antibodies than with IgM - for example, of 39 patients with IgG greater than 20 GPL units, 70% had a thrombotic event. treatment Identification of this syndrome means that many patients who were in the past diagnosed as suffering from a 'vasculitis' and treated with anti-inflammatory regimes and high-dose corticosteroids, will, if found to be suffering from APS, respond better to anticoagulation therapy: first-line treatment is low dose aspirin - 75-100 mg daily (1) patients with APS who have had a documented major thrombotic event require long-term treatment with warfarin or coumarin anticoagulation. An international normalized ratio of 3.0 or higher is required. The risk that warfarin treatment will result in haemorrhage is 1 in 14 per year (the risk of serious haemorrhage is 1 in 50 per year) - this compares favorably with the annual risk of 1 in 3 for new thrombosis in untreated patients and 1 in 5 in patients treated with aspirin alone or lower doses of warfarin. prognosis a high lifetime risk of thrombosis is conferred by the presence of antiphospholipid antibodies in the blood of 'young' people who suffer strokes, up to 20% of them have antiphospholipid syndrome up to 20% of cases of recurrent miscarriage have antiphospholipid syndrome up to 20% of cases of DVT have antiphospholipid syndrome there is a possibility that the antibodies directed against phospholipids, such as those found in antiphospholipid syndrome, may have a causative role in the development of atheroma Much Love, Deanna LUPUS Serenity Prayer... Lord, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to hide the bodies of doctors I shot when they said, You're perfectly healthy, it's all in your head " Quote Link to comment Share on other sites More sharing options...
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