Summary: Restoring the immune system
- Some researchers think that improving the responses of the immune system will help to keep viral load down, but others think that doing anything which stimulates the cells of the immune system will only encourage HIV production by immune cells which are already infected.
- An immune boosting treatment is one that improves the health of the immune system - the body's defence against infection.
- The main forms of immune boosting that are important in HIV infection are: increasing the number of CD4 T-cells, and improving the ability of the immune system to recognise infectious agents and stop them from multiplying.
- It may be best to use immune boosting treatments at the same time as antiretroviral drugs for the best results.
- Cytokines send messages between immune cells. Interleukin-2 is the cytokine investigated most of all in HIV treatment so far. Interleukin-2 causes large increases in CD4 T-cell numbers in HIV-positive people with relatively healthy immune systems. Further trials need to be done to show if interleukin-2 keeps people healthy for longer, and these are now taking place in Europe and North America.
- Anti-HIV drugs also boost the immune system. Big rises in CD4 cell counts have been seen after four to six months of treatment with triple drug therapy.
- The immune systems of some people who take anti-HIV drugs show signs of returning towards a normal state of balance after a year or so. The immune system begins to produce new CD4 T-cells and to re-build its 'memory bank' against some infections.
- There is no proof yet that people taking antiretroviral drugs begin to develop immune responses that can keep HIV under control without drugs.
- Vaccines which can stimulate the immune system into fighting HIV are also being tested. No vaccine tested has yet shown positive results.
- Anti-oxidants are chemicals which can reduce the damage caused by energy production in human cells. Molecules called free radicals cause the damage. These seem to be present at especially high levels in HIV-infected people, and some researchers think they are harmful to the immune system.
- Some vitamins and minerals are very good anti-oxidants, and it has been suggested that taking substances like vitamin C and glutathione can improve the immune system's response to HIV. There is no clear evidence from studies to support or discredit this approach.
