DOCTORS involved in treating people with AIDS in Ireland are seeing a remarkable improvement in patients as a result of the new treatments available. Their approach to treatment has been revolutionised, according to Dr Gerard Sheehan, consultant in infectious disease in the Mater and Beaumont hospitals in Dublin.
"The majority of my patients are on the treatment and the majority have responded as predicted. It is possible that a lot of the damage to the immune system is irreversible even if you wipe out the HIV. But at least we are stopping it progressing."
Dr Fiona Mulcahy, genitourinary physician at St James's Hospital in Dublin, says the number of Irish people dying with AIDS should reduce dramatically and that it will become a "chronic illness with long term implications".
According to Dr Mulcahy, they "are hitting hard and hitting early" with newly diagnosed patients; the drugs taken on their own are useless but, taken in combination, attack the virus.
In the past the only indicator was a Tcell count which told of the number of white cells in the blood, she says. "But at that stage the immune system was being hammered. Now we can move before the immune system is damaged. What we want to do is prevent latency - the virus hiding away in sanctuary sites such as the brain. However it is also very effective for people who have been HIV positive for a long time, bringing down their viral load and improving their overall health."
HIV outpatient clinics have become far busier. Now patients are being treated without having to be hospitalised and are being seen regularly because of the complicated medication.
But it's not all plain sailing, says Dr Sheehan. There are bad side effects with the drugs.
"There is a danger that the pendulum of optimism will swing too far. We were all scorched by the over optimism with AZT in the early 1990s. Time will tell here."
Both doctors emphasise that compliance with the treatment regime is very important for it to work. "If the drugs are taken in an intermittent way they will select out for resistance. If you were to use a single drug, there will already be in existence the genetic mutant to deal with that drug. However if you use three simultaneously, the biology of the organism is such that it is highly unlikely it would have the mutation of simultaneously dealing with the three. So it is better to do nothing than to do it in a haphazard way," adds Dr Sheehan.
PREVIOUSLY, Dr Sheehan explains, a patient could apparently be doing very well with a high Tcell count but it would not be possible to know if the virus would progress rapidly or slowly in that individual. The introduction of viral load testing means that prediction is now possible.
Viral load testing, a molecular test which measures the number of virus particles in the blood, has been carried out at the Virus Reference Laboratory (VRL) in UCD since July 1996.
The test was introduced very quickly at the VRL and so far more than 1,500 have been carried out. It is routinely available in the State and the number being tested is increasing. The Department of Health was very open to introducing the testing, according to Prof William Hall, director of the Virus Reference Laboratory, who saw it as an acute need in this country when he took over the laboratory last year.
Someone untreated with advanced disease could have millions of particles per millilitre in the blood but the test can measure down to 500 particles, he explains.
"People on the triple therapy have their viral load reduced from close to a million to undetectable levels in the space of several weeks. Before, the only test you had was the CD4 count. In some people that was a good marker but not of how active the virus was. However, in some cases, we know now that a person could have a high CD4 count but also have a high viral load," says Prof Hall who is also Professor of Medical Microbiology in UCD and a consultant at St Vincent's Hospital.
The viral load test, which costs £80, can assist a physician in predicting the development of the virus in new patients, just tested, who have never been treated with drugs, and predict their response to therapy, he explains. "Once they are put on treatment if the viral load does not go down you can change the combinations of drugs. Or if someone is on the drugs for a long time and their viral load begins to increase it suggests a resistance and the physician can make changes."
Prof Hall explains that they had been unsure if blood tests were reflecting the amount of virus present because the main reservoir for HIV is the lymph node tissue. "However biopsies have been done recently and have shown that the blood tests are accurate. But that is not to say that there may not be a reservoir in the brain, lymphatic tissue or gut.
The VRL now has a data bank so that the progress of each patient can be logged and monitored.
Prof Hall adds that the VRL also found an additional place in the HIV cycle for the use of another drug to fight the virus. "We have made this discovery but the drug is a cancer drug and very toxic so we have to find a way of making it less toxic."
AT St James's Hospital, Dr Mulcahy says that Ireland is more than holding its own in the treatment of AIDS. "We are very lucky. The viral load test is available to all, while it is restricted in the UK. We have faster access to drugs here than in the UK and they have a number of monetary restrictions there."
Dr Sheehan concurs. "The standard of Irish nursing is also extraordinarily high. I suspect we are doing a better job than the British. The NHS means that doctors are very sharply limited by cost implications and proof is demanded before something can be done. In some ways we are also better than the US because we have universal access for patients because it is paid for by the State."
The issue which will now face those treating AIDS is if and when to stop treatment. "This is the most controversial issue of all," says Dr Sheehan. "Can HIV be eradicated or cured? There are theories that if you get a total suppression of HIV in the blood and maintain it for more than three years you might have eliminated HIV from the body. We do not know at the moment but it is a plausible theory. But that is contingent on a number of things that may or may not be true. It will probably take five or 10 years to prove it one way or another."