1 June 2012
A new treatment plan for HIV patients may lead to a significant reduction in the use of medicines. Patients using this treatment go one week without medication after two weeks of drug use. The result appears to be as effective as continuous medication. These are the findings of scientists from the University of Amsterdam (UvA) based on a new computer model. They collaborated with an international research team of doctors and virologists. Their findings appeared in the scientific journal PLoS ONE on 27 April 2012.
The treatment of HIV with Combination Antiretroviral Therapy (CART) is particularly successful. The only condition is that the patient needs to begin with the treatment as soon as possible after infection. The increased life expectancy of HIV-positive patients has, however, led to the need for long-term medication with a greater risk of side effects and higher health care costs as a result. Therefore, there is much interest in the structural interruption of therapy (Structured Treatment Interruptions, STI). STI appear to now, however, often increase the risk of death and also increases the chances of the virus spreading further.
The researchers, led by UvA professor Peter Sloot, have developed a computer model which enables scientists to precisely determine why STI has been unsuccessful up to this point. The creation of reservoirs for the HIV virus in cells that are part of the immune system plays an important role according to the researchers. The new computer simulation has shown that an optimum treatment consists of a medication schedule of two weeks followed by interruption of medication for a week. This treatment can help the immune system recover, has less side-effects and the efficacy of the treatment appears to be as good as continuous medication without interruption. This could lead to a reduction in the use of medication from 30 to 40 percent per patient.
The researchers calculated the HIV virus dynamics and immune response of 250 virtual patients using a wide range of different forms of therapy interruption. At various times, the immune system of the patients was subjected to a simulated bacterial infection. Where possible, the results were compared with in vitro and in vivo studies of mice and men. The new algorithmic method enabled researchers to do virtual experiments that have never been conducted in clinics for ethical reasons.
E. Mancini, F. Castiglione, M. Bernaschi, A. de Luca and P.M.A. Sloot: ‘HIV Reservoirs and Immune Surveillance Evasion Cause the Failure of Structured Treatment Interruptions: A Computational Study', in PLoS ONE, 27 April 2012.