05 Mar 2013, BioSpectrum Bureau , BioSpectrum
Singapore: A group of researchers from the Johns Hopkins Children's Center, the University of Mississippi Medical Center and the University of Massachusetts Medical School (all from the US) have for the first time ever, claimed to have found a "functional cure" in an HIV-infected infant. The findings may help pave the way to develop methods to eliminate HIV infection in children. The research was funded by the National Institutes of Health and by amfAR, the Foundation for AIDS Research.
While Dr Deborah Persaud, lead author of the report and virologist at the Johns Hopkins Children's Center, and Dr Katherine Luzuriaga, immunologist at the University of Massachusetts Medical School, headed the team of laboratory investigators; Dr Hannah Gay, associate professor of pediatrics at the University of Mississippi Medical Center and pediatric HIV specialist, provided treatment to the baby.
The infant described in the report was born to an HIV-infected mother and underwent remission of HIV infection after receiving antiretroviral therapy (ART) within 30 hours of birth. A series of tests showed progressively diminishing viral presence in the infant's blood, until it reached undetectable levels 29 days after birth.
The infant remained on antivirals until 18 months of age, at which point the child was lost to follow-up for a while and, the researchers say, stopped treatment. Ten months after discontinuation of treatment, the child underwent repeated standard blood tests, none of which detected HIV presence in the blood. Test for HIV-specific antibodies, which is the standard clinical indicator of HIV infection, also remained negative throughout.
The investigators say that the prompt administration of antiviral treatment likely led to this infant's cure by halting the formation of hard-to-treat viral reservoirs, which are dormant cells responsible for reigniting the infection in most HIV patients within weeks of stopping therapy.
The infant has now deemed "functionally cured," a condition that occurs when a patient achieves and maintains long-term viral remission without lifelong treatment and standard clinical tests fail to detect HIV replication in the blood. In contrast to a sterilizing cure, which is a complete eradication of all viral traces from the body, a functional cure occurs when viral presence is so minimal, it remains undetectable by standard clinical tests, yet discernible by ultrasensitive methods.
The investigators caution they don't have enough data to recommend change right now to the current practice of treating high-risk infants with prophylactic, rather than therapeutic, doses but the infant's case provides the rationale to start proof-of-principle studies in all high-risk newborns. "Our next step is to find out if this is a highly unusual response to very early antiretroviral therapy or something we can actually replicate in other high-risk newborns," said Dr Persaud. Dr Luzuriaga said that, "Complete viral eradication on a large scale is our long-term goal but, for now, remains out of reach, and our best chance may come from aggressive, timely and precisely targeted use of antiviral therapies in high-risk newborns as a way to achieve functional cure."
A single case of sterilizing cure has been reported so far. It occurred in an HIV-positive man treated with a bone marrow transplant for leukemia. The bone marrow cells came from a donor with a rare genetic mutation of the white blood cells that renders some people resistant to HIV, a benefit that transferred to the recipient. Such a complex treatment approach, however, is neither feasible nor practical.