Combined antiviral therapy reduces HIV-1 plasma load and improves CD4 counts but does not interfere with ongoing lymphocyte apoptosis

The Effect of Central Nervous System Penetration Effectiveness of Highly Active Antiretroviral Therapy on Neuropsychological Performance and Neuroimaging in HIV Infected Individuals

The incidence of HIV-associated dementia has been greatly reduced in the era of highly active antiretroviral therapy (HAART); however milder forms of cognitive impairment persist. It remains uncertain whether HAART regimens with a high degree of central nervous system penetration effectiveness (CPE) exert beneficial neurological outcomes in HIV-infected (HIV+) individuals on stable treatment. Sixty-four HIV-infected adults on HAART were assigned a CPE score using a published ranking system and divided into high (≥7; n = 35) and low (<7; n = 29) CPE groups. All participants completed neuropsychological testing in addition to structural neuroimaging. Neuropsychological tests included measures known to be sensitive to HIV with values converted into standardized scores (NPZ-4) based on published normative scores. A semi-automated methodology was utilized to assess brain volumetrics within cortical (grey and white matter) and subcortical (thalamus, caudate, putamen) regions of interest. Analyses assessed NPZ-4 and brain volumetric differences between HIV+ individuals with high and low CPE scores. No significant differences in brain integrity were observed between the two groups. Long-term HAART regimens with a high degree of CPE were not associated with significantly improved neuropsychological or neuroimaging outcomes in HIV+ adults. Results suggest that alternate mechanisms may potentially contribute to better neurological outcomes in the era of HAART.

L-carnitine reduces lymphocyte apoptosis and oxidant stress in HIV-1-infected subjects treated with zidovudine and didanosine

Apoptosis is critical to the progression of human immunodeficiency virus-1 (HIV-1) infection. It appears reasonable that antiretroviral therapies may not achieve a full control of the infection in the absence of an impact on apoptosis. We assigned 20 asymptomatic HIV-infected subjects with advanced immunodeficiency to receive either zidovudine (AZT), and didanosine (DDI) or the same regimen plus L-carnitine, a known antiapoptotic drug, for 7 months. Immunologic and virologic parameters were measured at baseline and after 15, 60, 120, and 210 days of treatment. We assessed on each time point the following: (a) the frequency of peripheral blood apoptotic CD4 and CD8 lymphocytes, CD4 and CD8 cells with disrupted mitochondrial membrane potential, and CD4 and CD8 cells undergoing oxidant stress; (b) the expression of the molecular markers of apoptosis Fas and caspase-1; and (c) the expression of p35/cdk-5 regulatory subunit that is involved in regulating cell survival and apoptosis. Absolute CD4 and CD8 counts and plasma viremia were also measured. Apoptotic CD4 and CD8 cells, lymphocytes with disrupted mitochondrial membrane potential, and lymphocytes undergoing oxidant stress were greatly reduced in subjects treated with AZT and DDI plus L-carnitine compared with those who did not receive L-carnitine. Fas and caspase-1 were down-expressed and p35 over-expressed in lymphocytes from patients of the L-carnitine group. No difference was found in CD4 and CD8 counts and viremia between the groups. No toxicity of L-carnitine was recognized. The addition of L-carnitine is safe and allows apoptosis and oxidant stress to be greatly reduced in lymphocytes from subjects treated with AZT and DDI.

Increased soluble Fas in HIV-infected hemophilia patients with CD4+ and CD8+ cell count increases and viral load and immune complex decreases

Previous studies interpreted increases of soluble Fas (sFas) in the plasma during disease progression in HIV-infected patients as evidence of increased apoptosis of CD4(+) lymphocytes. We studied whether sFas and sFas ligand (sFasL) plasma levels are associated with CD4(+) and CD8(+) lymphocyte counts, plasma viral load, and IgM, IgG, C3d, and gp120 complexes on circulating CD4(+) blood lymphocytes in long-term surviving HIV-infected hemophilia patients, most of whom were receiving HAART. Twenty-six hemophilia patients who were infected with HIV in the early 1980s were investigated in 1997, 1998, and 1999. HAART was initiated in 1996 and 1997 in most patients. Lymphocyte subpopulations and immune complex-coated CD4(+) lymphocytes in the blood were investigated by flow cytometry, plasma viral load (HIV-1 mRNA copies/ml plasma) was tested with HIV-1 QT Nuclisens kits, sFas (ng/ml) and sFasL (ng/ml) plasma levels were measured with MBL ELISA kits, and the in vitro response of patient lymphocytes was tested in cell cultures. During the period from 1997 to 1999 we observed an increase in sFas plasma levels (p = 0.003) as well as in CD4(+) (p = 0.004) and CD8(+) (p = 0.023) cell counts; a decrease in IgG (p = 0.047), C3d (p = 0.024), and gp120 (p = 0.001)-coated CD4(+) lymphocytes in the blood; and a decrease in the number of impaired mitogen stimulation assays (p = 0.013). sFas was negatively associated with viral burden (r = -0.662, p = 0.0002) as well as with CD4(+)IgM(+) (r = -0.554, p = 0.004), CD4(+)IgG(+) (r = -0.431, p = 0.031), CD4(+)C3d(+) (r = -0.551, p = 0.041), and CD4(+)gp120(+) (r = -0.430, p = 0.041) blood lymphocytes, CD8(+)DR(+) cell counts (r = -0.700, p = 0.016), and impaired in vitro responses of patient lymphocytes to PHA (r = -0.475, p = 0.016). sFasL was negatively associated with total lymphocyte counts (r = -0.433, p = 0.027), as well as with absolute numbers of CD3(+) (r = -0.492, p = 0.011) and CD8(+) (r = -0.432, p = 0.027) cells. We conclude that, contrary to expectations, sFas plasma levels increased in long-term surviving HIV-infected hemophilia patients receiving HAART, concomitant with increases in CD4(+) and CD8(+) cell counts. Increased sFas may reflect the growing pool of T lymphocytes that recovers because of a decreasing viral burden and a decreasing immune complex load of CD4(+) lymphocytes.