With the surprising announcement earlier this week that a baby born with HIV appears to have been cured of the virus, AIDS researchers have reacted with cautious optimism mixed with concerns that the finding may led some HIV patients to mistakenly assume that they can safely go off their medications if they don’t have detectable levels of the virus.
“No one is recommending that anyone stop taking anti-retroviral therapy,” said Dr. Rowena Johnston, vice president and director of research at the Foundation for AIDS Research (amfAR), a non-profit organization based in New York City. While adults are usually diagnosed with the virus too late to be cured with treatments, infected infants treated within days of birth could potentially be cured of HIV, but it’s too soon to tell from this one case.
“What we don’t know is whether this baby’s experience is generalizable to the larger infant population infected with HIV,” Johnston said.
The infant described in the report, presented Sunday by University of Massachusetts Medical School researchers and others at an AIDS conference being held in Atlanta, had an unusual set of circumstances: born to a mother who was not diagnosed or treated for HIV until right after childbirth and treated with a potent regimen of three drugs within 30 hours after birth.
Fewer than 200 infants a year are born in the U.S. with HIV because most mothers are tested and treated with anti-retroviral drugs during pregnancy, which usually prevents transmissions to newborns. Babies born to infected mothers usually get a small dose of one drug to prevent infection and are only given larger doses of several drugs for treatment if they’re found to be infected weeks or months later.
Researchers believe the earlier treatment in this one infant’s case may have stopped the formation of dormant cells, called reservoirs, that carry the virus’s DNA but aren’t eradicated by treatment.
While the baby stopped the drug therapy at 18 months of age and remains free of infection 10 months later, most in the scientific community -- including the researchers themselves -- would like to see longer term follow-up before determining with certainty that the infection was indeed cured.
“We’re calling this a functional cure rather than a complete cure because when we do ultrasensitive tests, we’re detecting, on occasion, very low levels of viral DNA in cells,” said Dr. Katherine Luzuriaga, an immunologist at the University of Massachusetts Medical School, who helped present the case at the conference. “We definitely want to follow this baby over a longer period of time,” she added, and treatment could be resumed if the actual virus is once again detected in the child’s blood.
She and her colleagues also presented data at the conference on Monday describing a potential eradication of HIV in five infected teenagers -- who have been taking anti-retroviral drugs like AZT since about two months after they were born -- compared to less successful control of the virus in four teens who began treatment later in infancy.
“We’re conducting further studies on these five teens to see whether it would be safe or prudent to consider a trial off of anti-retroviral therapy,” Luzuriaga said. “We know from our sophisticated tests that they have very low levels of reservoir cells,” so a cure could be more likely than with those teens who have higher levels.
That needs to be done under research conditions with careful monitoring to ensure that the virus doesn’t come back full force in children who discontinue treatment.
“We certainly do not want to recommend to parents or physicians taking care of children infected with HIV that they should try to stop the therapy to see if the child has been cured,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which provides funding for HIV research conducted by Luzuriaga and others. “The last thing you want is people willy nilly going off these drugs.”
But thousands of children and young adults in this country who have been treated for HIV since infancy -- often with no detectable signs of the virus -- could be candidates for future studies to test whether they’ve been cured.
“We in the field may have cured some babies without realizing it, and they may still be on the drugs through childhood, so it’s important to study this further,” Fauci said.
Normally, babies born to HIV-infected mothers are put on a lower prophylactic dose of medications immediately after birth to prevent infection, according to Johnston. “It may take several weeks to find out if the infant is infected,” she said, “and several more weeks to switch from the preventive drug to the stronger treatment.” During that time, reservoir cells may have had a chance to form, which would make the infection impossible to cure.
“Once virus gets seeded in these reservoir cells, we know that the virus will return if a patient stops therapy, often within two months,” said Dr. Mark Wainberg, director of the McGill University AIDS Centre in Montreal.
AIDS researchers haven’t yet determined at what point in time reservoir cells form after the body has become infected with the HIV virus, but other research presented at the conference suggests that those with low levels of these cells -- due to early treatment soon after infection -- often experience a later recurrence of their infection up to a year or two after they stop taking their drugs.
That could prove to be the case with the baby described at the conference, according to Luzuriaga, since the child also has extremely low levels of these cells.
While HIV researchers have been eager to explore further research to answer these questions, Luzuriaga and others worry that their efforts could be slowed by a cut in federal funding triggered by the sequester that went into effect last week.
The National Institutes of Health, which includes Fauci’s institution, implemented a 10 percent across the board reduction in research grants for this year in anticipation of the federal sequester, which went into effect last week. “Whether or not there will be reconstitution of grants is still up for discussion,” Fauci said, “but it’s having a dampening effect on our enterprise.”
Luzuriaga said her lab gets a few million dollars annually in NIH funds. “That 10 percent drop is a significant cut and we are very concerned about our ability to do good science.”Deborah Kotz can be reached at email@example.com. Follow her on Twitter @debkotz2.