chemotherapy that destroyed most of his immune cells. He also endured total body irradiation and was given immunosuppressive drugs to keep his body from rejecting the stem cells. On the day of the transplant, his antiretroviral treatments and medication stopped. He then received immunosuppressive treatment for 38 months to make sure the new cells weren't rejected.

During this 38 month period, the donor CD4 cells repopulated the mucosal immune system of the gut to such a degree that the frequency of CD4 cells was almost twice as high as in HIV-negative people Brown's age. This result was also observed in ten HIV-negative individuals who received stem cell transfers. After two years the patient had the CD4 count of a healthy adult his age. Now, HIV remains undetectable in Brown by all available tests.

This method is not without it's difficulties and risks. Brown endured two relapses and underwent two stem cell transplants. He also suffered from a few neurological problems that caused temporary blindness and memory issues. He's still receiving physical therapy to help restore his coordination along with speech therapy. His personality has also shifted; he's much more blunt, which may be associated with his neurological troubles.

Now that Brown is the first patient officially cured of HIV, researchers searching for a cure may focus on halting the production of CCR5-bearing cells through transplants or gene therapy of genetically engineered stem cells. Last year scientists met in Berlin to discuss identifying CCR5-delta32 homozygous donors to expand their supply of stem cells.

US scientists may soon duplicate these results following the executive order 13505 issued by President Obama in March of 2009, which eliminated many of the previous federal barriers surrounding stem cell research. Several US groups have already received funding to explore techniques for engineering and the introduction of CCR5-deficient stem cells. Even if this treatment proves effective, it will still be expensive in the beginning and reserved for patients lacking options or with cancer requiring bone marrow or stem cell transfers. And even if this method proves to be a "cure," the war with HIV is not over. HIV is such a difficult disease to eradicate because it changes rapidly. Although rare, there's already a mutant form of the virus that docks with the CXCR4 receptor instead of the CCR5, making this form of treatment ineffective.

Read more at aidsmap.com

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