HIV And Arterial Inflammation
Researchers at Massachusetts General Hospital found that there is a high degree of vascular inflammation among patients with HIV without having cardiovascular risk factors. They found that these patients had a degree of inflammation of arteries comparable to those with cardiovascular disease. Steven Grinspoon, MD, director of the MGH Program in Nutritional Metabolism and a member of the Neuroendocrine Unit, the study’s principal investigator, said the new data suggests the mechanisms by which the activation of the immune system leads to a vascular inflammation and an increased cardiovascular risk of complications in patients with HIV. The study will be published in a special issue of JAMA in conjunction with the International AIDS Conference.
The cardiovascular risk refers to complications that can occur in the heart or the blood vessels. Cardiovascular complications include myocardial infarction, stroke, peripheral arterial disease, angina, heart failure, etc.. It seems that HIV infection increases cardiovascular risk by increasing inflammation in the arteries and increasing cholesterol levels. These changes play an important role in forming plaque lesions that can cause heart attack or stroke. It is known that HIV alters the immune system by infecting helper T lymphocytes. This results in immune suppression and significant increase in the risk of infections and cancer.
Researchers conducted a study on 81 individuals: 27 of them had HIV infection and no cardiovascular disease but were receiving antiretroviral therapy, 27 people were uninfected and without cardiovascular disease, and 27 people were uninfected but with atherosclerosis. All the 81 study participants were examined with PET and CT scans. The results showed that people with HIV infection without known cardiovascular disease had a level of vascular inflammation comparable to those with cardiovascular disease. Following investigations, researchers found that patients with HIV infection had increased CD163, a marker of inflammation. CD163 is in fact a marker of monocytes activation which are involved in the formation of unstable plaque. These plaques are more susceptible to rupture, and therefore more dangerous. Rupture of these plaques can lead to a heart attack.
Scientists also took into account traditional risk factors for cardiovascular disease, that is abdominal obesity, hypertension, smoking, high cholesterol. Now, besides these risk factors should be taken into account also arterial inflammation. Researchers believe that if investigations such as PET or CT scans cannot be used as screening method, measuring levels of inflammation marker CD163 may be useful for determining cardiovascular risk among HIV positive patients. Grinspoon, professor of Medicine at Harvard Medical School, believes that the new target to reduce inflammation in HIV positive patients could be monocytes activation, namely CD163.