C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines. This is the process by which T cells are attracted to specific tissue and organ targets. Many forms of HIV, the virus that causes AIDS, initially use CCR5 to enter and infect host cells. A few individuals carry a mutationknown as CCR5-Δ32 in the CCR5 gene, protecting them against these strains of HIV.
In humans, the CCR5 gene that encodes the CCR5 protein is located on the short (p) arm at position 21 on chromosome 3. Certain populations have inherited the Delta 32 mutation resulting in the genetic deletion of a portion of the CCR5 gene. Homozygous carriers of this mutation are resistant to M-tropic strains of HIV-1 infection.
By ANTHONY CASTELLANO March 4, 2013
A Mississippi baby born with HIV more than two years ago appears to be the first documented case of a child’s being cured of the virus, according to doctors and scientists.
The unidentified child has now been “functionally cured” and has been off medication for about a year with no signs of the HIV infection. If the child remains healthy, it would mark only the second time in the world’s history that a person has been cured of HIV, which is the virus that causes AIDS.
The landmark case was announced Sunday at the 2013 Conference on Retroviruses and Opportunistic Infections in Atlanta.
Dr. Deborah Persaud of Johns Hopkins University in Baltimore was one of the lead researchers and author of the report, which was released by The Foundation for AIDS Research (amfAR).
The infant was diagnosed with HIV at birth to a mother who did not receive prenatal care or HIV treatment, Dr. Rowena Johnston, director of amfAR, told ABC News.
The infant was transferred to the University of Mississippi Medical Center and started on antiretroviral treatment about 30 hours after birth. Doctors took the apparently unusual step of prescribing three aggressive drugs (AZT, 3TC, nevirapine) at once after birth.
The above drugs create a resistence CC5 mutation in the white blood cells that prevent HIV cells from forming.
The baby was on treatment and in care until 12 to 15 months of age, at which point the baby was lost to follow-up after doctors lost contact with the mother and the baby stopped receiving any medication. The baby returned for care at 23 months of age.
Surprisingly, viral loads were still undetectable, despite being off treatment for almost a year.
Johnston said the results were all the more shocking because doctors do not usually recommend stopping treatment at any time in children with HIV from birth.
The results surprised Dr. Hannah Gay, a pediatric HIV specialist at the University of Mississippi, who was treating the child.
“My first thought was to panic. I thought, ‘Oh my goodness, I have been treating a child who is not actually infected,'” she said.
A battery of “highly sensitive” tests confirmed the absence of HIV, according to a news release.
Dr. Anthony Fauci, with the National Institutes of Health, cautions that more studies are needed before calling the results a breakthrough.
“You have to be careful because this is just a single case and although the data looked pretty convincing that you got to be careful that this may not be broadly applicable to other situations,” Fauci told ABC News Radio.
In Mississippi, Gay gives the child a check-up every few months. “I just check for the virus and keep praying that it stays gone,” she told The Associated Press.
The mother’s HIV is being controlled with medication and she is “quite excited for her child,” Gay added.
The only other documented case of an HIV cure to date remains that of Timothy Brown, the so-called “Berlin patient.”
Brown’s story — arguably one of the most followed in the realm of HIV research — began in 1995 when he was diagnosed with HIV while attending school in Berlin. For the next 11 years, doctors treated him with anti-retroviral therapy, to which he responded positively.
His oncologist, Dr. Gero Hutter of the Charite Hospital in Berlin, opted to give Brown a stem-cell transplant to treat his leukemia. But rather than choosing a matched donor, he used the stem cells of a donor he found who had what is known as a CCR5 mutation, a mutation that makes cells immune to HIV.
The Mississippi case will likely spark new directions of research for adults, too.
“This could prevent a lifetime of treatment,” Johnston said. “We want people to understand just how game-changing this may be.”
Fauci of the National Institutes of Health says the results could have a global impact if they can be replicated.
“About a thousand babies a day are born HIV infected throughout the world,” he said.