Autoimmune destruction of platelet is seen in :(AIIMS May 95)
Antiphospholipid antibody syndrome
i. This syndrome occurs in 5% of the general population, but is associated with 50% cases of SLE.
ii. Patients have anti phospholipid antibodies such as lupus anticoagulant, anticardiolipin antibody or anti beta 2 glycoprotein (AIPG 2011) (Harrison-18th, edition Pg- 2736)
iii. Because phospholipids are integral parts of the control of coagulation, these antibodies can lead to a hypercoagulable state, i.e., anti phospholipid antibody syndrome.
Patients with antiphospholipid antibody syndrome fall into two categories.
1. Primary antiphospholipid antibody syndrome
· In these cases there is no evidence of other autoimmune disease, the patient exhibit only the manifestations of antiphospholipid antibody syndrome.
2. Secondary antiphospholipid antibody syndrome
· In this cases antiphospholipid antibody syndrome is associated with an autoimmune disease usually SLE.
Clinical manifestations of antiphospholipid antibody syndrome:
ii. Arterial and venous thromboembolism, avascular osteonecrosis.
§ Coagulopathy: Platelet dysfunction, prothrombin deficiency.
§ Acute ischemia (CVA, TIA, encephalopathy);
§ Livedoreticularis, acrocyanosis, wide spread cutaneous necrosis,
§ Marantic endocarditis, myocardial infarction, peripheral arterial disease. pulmonary hypertension.
§ Recurrent spontaneous abortion predominantly second trimester, IUGR, preeclampsia,
viii. Catastrophic antiphospholipid syndromes
In lupus anticoagulant thrombosis occurs (there is no increase in thrombocytes).
Coagulation tests in lupus anticoagulant
PTT → Prolonged
PT → Normal
Fibrinogen → Normal
a. Antiphospholipid antibodies bind to cardiolipin antigen, used in serologic tests for syphilis, and therefore lupus patients may have a false-positive test result for syphilis.
b. Thrombocytopenia occurs.
c. Sterility is not a feature