Arterial ischemic stroke in HIV: Defining and classifying etiology for research studies

Abstract

HIV infection, and potentially its treatment, increases the risk of an arterial ischemic stroke. Multiple etiologies and lack of clear case definitions inhibit progress in this field. Several etiologies, many treatable, are relevant to HIV-related stroke. To fully understand the mechanisms and the terminology used, a robust classification algorithm to help ascribe the various etiologies is needed. This consensus paper considers the strengths and limitations of current case definitions in the context of HIV infection. The case definitions for the major etiologies in HIV-related strokes were refined (e.g., varicella zoster vasculopathy and antiphospholipid syndrome) and in some instances new case definitions were described (e.g., HIV-associated vasculopathy). These case definitions provided a framework for an algorithm to help assign a final diagnosis, and help classify the subtypes of HIV etiology in ischemic stroke.

Figure 1.. An algorithm to define the etiology of HIV-related ischemic stroke for research studies

Minimum battery of tests include the following: HIV test, full blood count and blood film and urine dipstix assay, anticardiolipin antibodies, lupus anticoagulant, anti–β₂-glycoprotein, hemoglobin for sickle cell disease, serum syphilis treponemal (immunoassay + agglutination test) and nontreponemal tests, chest x-ray, CSF—microscopy, biochemistry, India ink and acid fast bacilli stains, blood culture, tuberculosis culture, unenhanced CT, ECG, and carotid/vertebral duplex ultrasound and echocardiography. APS = antiphospholipid syndrome; OI = opportunistic infection; TTP = thrombotic thrombocytopenic purpura.

Figure 2.. Different pathologic description of vasculopathy associated with HIV infection

(A, B) Atherosclerotic vasculopathy. (C) HIV-associated vasculitis. (D, arteriolosclerosis; E, lipohyalinosis) Small vessel disease. (F) Nonatherosclerotic vasculopathy. (A–E) From personal archives. (F) Reproduced with permission from the Archives of Neurology. 2006. 63: 1640–1642. Copyright© 2006 American Medical Association. All rights reserved.