Large Vessel Adventitial Vasculitis Characterizes Patients with Critical Lower Limb Ischemia with as Compared to without Human Immunodeficiency Virus Infection

OBJECTIVES: Whether a human immunodeficiency virus (HIV)-associated vasculitis in-part accounts for occlusive large artery disease remains uncertain. We aimed to identify the histopathological features that characterize large vessel changes in HIV sero-positive as compared to sero-negative patients with critical lower limb ischemia (CLI). MATERIALS AND METHODS: Femoral arteries obtained from 10 HIV positive and 10 HIV negative black African male patients admitted to a single vascular unit with CLI requiring above knee amputation were subjected to histopathological assessment. None of the HIV positive patients were receiving antiretroviral therapy. RESULTS: As compared to HIV negative patients with CLI, HIV positive patients were younger (p<0.01) and had a lower prevalence of hypertension (10 vs 90%, p<0.005) and diabetes mellitus (0 vs 50%, p<0.05), but a similar proportion of patients previously or currently smoked (80 vs 60%). 90% of HIV positive patients, but no HIV negative patient had evidence of adventitial leukocytoclastic vasculitis of the vasa vasorum (p<0.0001). In addition, 70% of HIV positive, but no HIV negative patient had evidence of adventitial slit-like vessels. Whilst T-lymphocytes were noted in the adventitia in 80% of HIV positive patients, T-lymphocytes were noted only in the intima in HIV negative patients. The presence of femoral artery calcified multilayered fibro-atheroma was noted in 40% of HIV positive and 90% of HIV negative patients with CLI. CONCLUSIONS: An adventitial vasculitis which characterizes large artery changes in CLI in HIV-infected as compared to non-infected patients, may contribute toward HIV-associated occlusive large artery disease.