I've heard that some rich people with blood infections, especially cancer or HIV, get their blood removed and exchanged with fresh blood every six months or so. Is it possible to control HIV infection or CD4-cell counts in the blood by doing this? If so, how much does it cost?

S.V.

I am sure that it is true that some rich people get their blood exchanged in an effort to rid their bodies of cancer, HIV (the virus that causes AIDS) or other infections. Does it work? Probably not. There are many places in the United States and elsewhere that will perform all sorts of procedures with little, if any, proof of claimed benefits for patients. From high colonics (infusing the large intestine with large quantities of liquid via the rectum) to intravenous vitamin C, these treatments are typically expensive, and insurance companies never cover them.

Certainly, there are some alternative therapies that help, but many do not. How do you know which ones may offer some benefit? Well, you can ask your physician, but that is not always helpful. Many, if not most, physicians frown upon alternative treatments of any kind. You also can ask the alternative therapist. Although that sounds silly, I think that this is actually the best approach, particularly if you ask three specific questions.

The first question to ask someone offering alternative therapy is, "What is the expected benefit of the treatment?" If he or she has no answer to this question, or says that you will feel better and that it cannot hurt, then the treatment will probably not help HIV or cancer.

The next question to ask is, "What percentage of people will receive this expected benefit?" A list of people who had good results is not good enough evidence of benefit, because even with the worst of therapies, people often feel better for reasons that have nothing to do with the treatment. What is needed is a study that compares people who received the treatment with those who did not, to see if the treatment produced a better result than doing nothing. Before any new drug enters the market, it undergoes studies designed to find out if the drug works better than a placebo (a dummy pill) or a standard therapy for the condition the drug is intended to treat. Before I'd let someone exchange my blood, I would want to see evidence demonstrating that this treatment works better than a "sham" treatment (a procedure known to have no medical value).

The last question to ask is, "What are the risks?" If the person offering the alternative therapy answers that the treatment has no potential complications, I would be wary. Every treatment, whether traditional or alternative, can have some side effects. Do not believe assurances that "natural" treatments have no side effects, as is often claimed in discussion of herbs used for weight loss and other alternative therapies. Hemlock, poison mushrooms, and the toxic herb Chinese ephedra (ma huang) that the FDA is considering banning are all natural. They all can kill you.

What about blood exchange for HIV? If it really worked, it would be studied and would become standard therapy. Cost would not be much of an issue, at least in the United States. Standard drug cocktails (combinations of anti-HIV drugs) are already quite expensive, as much as $2,000 a month, and I do not think that a blood exchange would be that much more. But blood exchange does not make sense as a treatment for HIV. The drug cocktails remove virtually all of the billions of viruses that are made each day in someone infected with HIV, and still the infection is not cured. Removing a few more viruses every six months by blood exchange would not make a bit of difference.