An ultrasound-based comparative study on carotid plaques in HIV-positive patients vs. atherosclerotic and arteritis patients: atherosclerotic or inflammatory lesions?

BACKGROUND: We have previously described two cases of HIV-1-positive patients undergoing surgery for stenosis of the internal carotid arteries. Histology revealed an extensive inflammatory infiltration of the vascular wall and no evidence of atheromasic plaque. This unexpected pattern of carotid damage prompted us to perform a more accurate investigation of the characteristics of carotid plaques in a group of HIV-positive patients. The results were compared with those obtained from young patients affected by atherosclerosis of the epi-aortic vessels and patients with arteritis. METHODS: The patients underwent ultrasonography of the epi-aortic vessels using one of the latest generation power color-Doppler with 7.5 MHz probes. RESULTS: The study population included 61 HIV-positive patients and 47 HIV-negative patients (37 atherosclerotic and 10 with arteritis). Compared with HIV-negative atherosclerotic patients, there were significantly higher proportions of HIV-positive patients with iso-hypoechogenic lesions (81.8 vs. 29%) that were homogeneous both in their parietal and endoluminal portions (96.7 vs. 21.6% and 88.5 vs. 54.0%, respectively), with a smooth or slightly irregular surface (99.0 vs. 56.7%) (P=0.001 for all differences). No statistically significant differences were seen between HIV-positive and arteritis patients. CONCLUSION: Our study evidenced that the ultrasonographic structure of the epi-aortic lesions in HIV-positive patients substantially differ from those of the plaques in atherosclerotic patients, although they share similar characteristics with patients affected by arteritis. Further investigations are warranted to better define the structure and the mechanism of onset of these lesions.

Role of chlamydia infection in the pathogenesis of atherosclerotic plaques in HIV-1-positive patients.

BACKGROUND: Various authors have hypothesized a role of Chlamydia pneumoniae infection in the pathogenesis of atherosclerosis. To better understand the possible role of this infection in the pathogenesis of epi-aortic lesions in HIV-1-positive patients, the presence of anti-Chlamydia pneumoniae antibodies was evaluated in a group of individuals subjected to ultrasonography of the epi-aortic vessels. PATIENTS AND METHODS: The presence of specific antibodies in 129 subjects was determined; 59 patients were HIV-1-positive, of whom 30 had carotid plaques and 29 were without lesions. The control group was composed of 70 subjects. All were subjected to ultrasonography of the epi-aortic vessels. IgG, IgM and IgA anti-C. pneumoniae antibodies were measured with micro-immunofluorescence and positive sera were tested for C. trachomatis and C. psittaci. RESULTS: No subjects were positive for IgM. Both the IgA and IgG levels did not differ significantly in the three groups. The only highly significant variable was the use of protease inhibitors. CONCLUSION: Our data suggest that the damage to the carotid wall in HIV-1 patients was not due to C. pneumoniae.