Dear Ladies and Gentlemen
We extend our warmest thanks to you for participating in the Swiss HIV Cohort Study (SHCS). This study, which has been ongoing since 1988, has enabled us to understand the disease better and greatly improve the medical care provided for patients. Since 1988, data on the course of the disease has been collected and analysed from over 16,000 HIV-positive individuals. At this time, more than 7,500 people like you are actively taking part in the SHCS, with women making up almost one third of this number. Over 85% of study participants are taking drugs for HIV.
As in past years, we would like to tell you about the latest important findings and, in particular, thank you for your committed participation. For additional information and questions, please see your doctor or nursing staff. You can also visit the SHCS Web site (http://www.shcs.ch/).
HIV infection – not just an illness of the immune system
In the past few months it has become clear that long-lasting HIV infection compromises more than just the immune system. Without anti-retroviral therapy, the daily production of many billions of viruses leads to the activation of inflammatory cells, resulting in long-term stress on the body. In turn – even before the appearance of AIDS – this can lead to a loss of functional efficiency of the liver, kidneys, heart, blood vessels and bones. In the future, we will be attempting to better evaluate and understand these mechanisms within the SHCS.
HIV infection – a treatable chronic disease
Various studies also affirmed in 2009 that HIV infection in most patients can be treated successfully with available anti-retroviral drugs. Regular use of the drugs greatly reduces the risk of developing AIDS and significantly increases life expectancy, which should give a substantial number of people living with HIV the same life expectancy as people without HIV.
Difficulties arising in the treatment of HIV infection
Adherence: Difficult personal situations make it harder to follow (adhere to) HIV therapy properly. Before anti-retroviral therapy begins, it is therefore important to consider the living circumstances of our patients. In particular, addictions can have an impact on the success of treatment, which we were able to prove in two studies. On the one hand, patients who consume too much alcohol have problems taking the drugs properly. On the other, it could also be shown that patients with a history of intravenous drug use respond well to the treatment if they can put their lives in order within a substitution programme with methadone or heroin.
Long-term side effects: Since HIV treatment lasts many years, we are attempting to understand the long-term side effects more clearly in the SHCS. We have therefore expanded our questionnaire to better evaluate the side effects on the liver, kidneys, heart, blood vessels and bones. This knowledge will help us to adapt treatment more adequately in the future for individual patients who are assessed at being at a higher risk for such illnesses. In addition, we are examining whether specific side effects are due to inherited conditions.
When should HIV treatment begin?
In a large collaborative effort between a majority of European cohort studies, it could be demonstrated last year that it is beneficial to begin HIV treatment if the CD4 lymphocytes fall below 350 cells per microlitre of blood, even if patients do not feel ill yet. This may be related to the stress on the body caused by the daily production of billions of viruses as described above. Through the co-operation of SHCS experts, the European guidelines were therefore revised and issued in November 2009. Whether it is advantageous to begin treatment even earlier is unclear. Based on present knowledge, it is still not possible to estimate whether the advantages of starting treatment very early and inhibiting virus production outweigh the disadvantages of side effects and the development of resistance. This question is being researched in the international START study that Swiss patients will also be able to participate in starting in 2010.
Treating resistant viruses, new drugs
Fortunately, new drugs have come onto the market in the last two years that can also treat HIV strains that have been resistant so far. As part of the cohort study, we examined the use of these drugs with our patients and are now in a better position to use them in a more targeted, effective manner. Most of the corresponding drug combinations are somewhat more complicated to take and make greater demands on patients regarding adherence. Knowledge about the problem of resistant viruses is leading to positive results: an extensive assessment within the SHCS showed that the development of resistance is lower now than it was just a few years ago.
Besides the points mentioned above, SHCS assessments have also provided many other important results, including the mechanisms related to rebuilding the immune system during treatment, the reaction of HIV patients to vaccinations, the interaction between chronic hepatitis and HIV, and the cancer risk in HIV infections.
Your participation is still important
Your participation in the cohort study will enable us to continue to tackle the many challenges of the long-term treatment of HIV infection in the future. We are very grateful to you for your trust and consider ourselves fortunate to be able to return this trust in the form of good care, information and progress.
We wish you all the very best for the new year.