Minor Thoughts from me to you

A genetic mutation may hold an AIDS cure.

The startling case of an AIDS patient who underwent a bone marrow transplant to treat leukemia is stirring new hope that gene-therapy strategies on the far edges of AIDS research might someday cure the disease.

The patient, a 42-year-old American living in Berlin, is still recovering from his leukemia therapy, but he appears to have won his battle with AIDS. Doctors have not been able to detect the virus in his blood for more than 600 days, despite his having ceased all conventional AIDS medication. Normally when a patient stops taking AIDS drugs, the virus stampedes through the body within weeks, or days.

"I was very surprised," said the doctor, Gero Hutter.

The breakthrough appears to be that Dr. Hutter, a soft-spoken hematologist who isn't an AIDS specialist, deliberately replaced the patient's bone marrow cells with those from a donor who has a naturally occurring genetic mutation that renders his cells immune to almost all strains of HIV, the virus that causes AIDS.

Caveats are legion. If enough time passes, the extraordinarily protean HIV might evolve to overcome the mutant cells' invulnerability. Blocking CCR5 might have side effects: A study suggests that people with the mutation are more likely to die from West Nile virus. Most worrisome: The transplant treatment itself, given only to late-stage cancer patients, kills up to 30% of patients. While scientists are drawing up research protocols to try this approach on other leukemia and lymphoma patients, they know it will never be widely used to treat AIDS because of the mortality risk.