Higher levels of high-density lipoprotein (HDL) cholesterol, often called good cholesterol, are associated with better reduction in viral load in HAART treated patients, according to a Spanish study published in the May 2003 edition of AIDS.
HDL cholesterol is known to have a role in innate immune response as well as anti-inflammatory properties. In addition, apolipoprotein A1, a component of HDL cholesterol inhibits herpes simplex and also has some inhibitory effect on HIV.
Investigators wished to see if there was a relationship between HDL cholesterol concentrations and to see if there were similarities in the structure of HDL apolipoprotein A1 and HIV proteins involved in viral replication.
Eighty patients who had achieved a viral load below 200 copies/mL after two months of HAART were had their lipid profiles, HIV viral load, and immune profile monitored. Background demographic data, and medical histories were also obtained. Patients experiencing blips or rebounds in viral load were excluded from the study's final analysis.
Average age of patients in the study was a little over 38 years. Three-quarters were men, and 46% had previous experience of anti-HIV therapy before entry to this study. Viral load remained detectable on average for a little over 15 months. Average baseline CD4 cell count was 498 cells/mm3, total cholesterol was 5.09 mmol/L, and HDL cholesterol was 1.28 mmol/L. In 73 patients LDL cholesterol was also measured, with the average being 2.87 mmol/L.
After starting HAART, levels of HDL cholesterol were found by the investigators to be significantly associated with the time to undetectable viral load. The investigators also found that the Gag-p17 protein of HDL cholesterol apolipoprotein A1 and HIV "shared not only sequence similarity but also structural similarity".
The investigators comment, "our findings of a significant relationship between HDL and the time to undetectable viral load can imply that the HDL particle may have some antiviral properties based on its structure or function." An HDL antioxidant effect could inhibit HIV replication, or HDL could induce a direct immune response against HIV.
The Gag p-17 protein similarity between HIV and apolipoprotein A1 in HDL appears to interfere in the viral assembly of HIV, the investigators note.
The investigators conclude that should further studies confirm their findings, "we propose the intriguing possibility that inducing an increase in HDL-lipoprotein by diet and drugs and exercise could become an integral co-adjuvant in the treatment of AIDS."
Further information on this website
Cholesterol - factsheet
HIV's lifecycle - factsheet
Nutrition - booklet in the information for HIV-positive people series (pdf)
Alonso-Villaverde C et al. High-density lipoprotein concentrations relate to the clinical course of HIV viral load in patients undergoing antiretroviral therapy. AIDS, 17: 1173 - 1178, 2003.