D-dimer levels are markedly raised in HIV-related thrombotic thrombocytopenic purpura.

摘要

The association between HIV infection and thrombotic thrombocytopenic purpura (TTP) has been apparent since the late 1980s . The incidence of TTP in HIV-infected individuals has been estimated to be 15-40 times that in the general population . In South African hospitals it is now by far the commonest cause of TTP.Successful treatment depends on the early institution of plasma infusion or plasmapheresis, and it is often necessary to make the diagnosis in the presence of microangiopathic haemolytic anaemia and thrombocy-topenia alone before the full diagnostic pentad of features (including renal failure, neurological symptoms and fever) has emerged . This requires te exclusion of other possible causes for the clinical picture, including disseminated intravascular coagulopathy (DIC). The absence of abnormalities on a DIC screen is therefore iuoted as an important diagnostic criterion. However, although other coagulation parameters appear normal, we have frequently observed extremely high D-dimer levels inpatients with HIV-related TTP. We therefore analysed the results of coagulation screening in patients with HIV-related TTP and compared these with the findings in HIV-negative patients with TTP.