Call for earlier HIV treatments

In developed countries, most people with HIV are given a powerful cocktail of antiretroviral drugs.

The aim of these are to inhibit the replication of the HIV viruses and their damaging effects on the immune system.

Research published in the Lancet medical journal on Friday reveals that the latest combination therapies, called "highly-active antiretroviral therapy" (HAART) are producing excellent results so far.

However, the outcome was dependent on the state of the disease when the patient was diagnosed.

One measure of HIV progression is the number of a certain type of immune system cell - CD4 - which can be found in a blood test.

Immune destruction

CD4 cells are destroyed by the HIV virus, so the lower the number of CD4 cells, the more advanced the infection.

The research found that patients with fewer than 50 CD4 cells per microlitre had a strong chance of developing Aids, or dying, within three years, regardless of treatment.

A count between 50 and 99 reduced this risk by 25%, between 100 and 199, the risk fell by 50%, and the fall was even greater if the cell count was more than this, the risk fell still further.

Likewise, the number of copies of HIV in the blood also predicted outcome - the higher the level, the worse for the patient.

In patients with the worst combination of both measures, there was a one in two chance of either Aids developing or the patient dying within three years.

Sooner better

Doctors say it reinforces the need for patients to be diagnosed as soon as possible and started on antiretroviral treatment.

Professor Matthias Eggar, from the Department of Social Medicine at Bristol University, said: "This study is important because it helps to define when exactly in the course of the infection HAART should be initiated.

"Unfortunately, almost 60% of patients were late and started with a CD4 count below 200 cells or a viral load above 100,000 copies.

"In these patients the treatment would have been more effective had it been started earlier.

"We now need to address the reasons responsible for the delay in treatment in order to maximise benefit."