Perhaps you’ve seen the story of the 44-year-old American man reportedly “cured” of HIV in Germany–it’s been making the rounds over the past week. What’s actually happening here?
This is a story that dates back a few years; in fact, 80beats blogged about this case years ago when it first made the news. Back in 2007, the man—Timothy Ray Brown—was an HIV-positive patient suffering from acute myeloid leukemia. When standard chemotherapy couldn’t help him, his docs in Germany turned to a bone marrow transplant, with one twist.
Brown’s oncologist decided to look for a bone marrow donor who had a had a special genetic mutation that made the stem cells in it naturally resistant to HIV infection. His physician, Dr. Gero Huetter, was able to find this rare match and Brown got the bone marrow transplant. He needed a second stem cell transplant because the cancer came back. Today, he appears to be cancer free and doctors can’t find traces of the virus that causes AIDS either. [CNN]
Brown’s treatment made a splash in the news in 2008, when the doctors first reported on it. It has resurfaced this month because the researchers published a new study in the journal Blood updating his condition.
The researchers confirmed that Brown seems to have maintained his resistance to HIV for three years, confounding their expectation that he would become reinfected. They concluded that a “cure of HIV has been achieved in this patient.” [New Scientist]
Obsessive-compulsive mice, which were once pulling their hair out from too much grooming, are now sitting pretty. Their cure? A bone marrow transplant. In a study published today in Cell, scientists show an unsuspected link between a psychological disorder and the immune system.
Here’s how they did it:
Step 1 – Finding the Problem
Since excessive cleaning is a behavior, scientists first thought to look for defects in the mouse brain. They noticed that mice with a mutant version of the gene Hoxb8 were the ones cleaning themselves bald. Hoxb8 is important for creating microglia–nervous system repair cells that search for damage in the brain.
Although some microglia start out in the brain, others are born in the bone marrow and move in. Overall, adult mice with faulty Hoxb8 harbored about 15% fewer microglia in the brain than normal. [ScienceNow]
Since many microglia move from bone marrow to brain, the scientists decided to give the compulsive mice, with the mutant Hoxb8 gene, a marrow transplant.
For a study this week in the journal Nature Medicine, Kathleen Collins and her team have uncovered another of HIV’s dirty tricks: the virus can hide out in bone marrow cells and lie in wait for the right time to strike.
In recent years, drugs have reduced AIDS deaths sharply, but patients need to keep taking the medicines for life or the infection comes back, she said. That’s an indication that while the drugs battle the active virus, some of the disease remains hidden away to flare up once the therapy is stopped [AP]. One place the researchers already knew HIV could hide was inside resting T cells. However, Collins says, she thought T cells alone didn’t offer a complete picture of the virus’ ability to play hide-and-seek.