Published in The Hindu on March 7, 2013
A few days after the news broke of a “functional cure” in a HIV-positive Mississippian baby aged two-and-a-half, many questions have been raised whether the baby was indeed infected with HIV.
“There are many instances where the mother’s HIV particles (HIV RNA) can be present in the newborn’s blood,” Dr. N. Kumarasamy told this correspondent from Atlanta, U.S.
Dr. Kumarasamy is the Chief Medical Officer at YRG CARE, Chennai, and is currently attending the annual conference on Retroviruses and Opportunistic Infections in Atlanta. The results of the Mississippian baby were presented on Monday.
“Mother’s HIV particles can disappear from the newborn on their own without causing the disease. It can happen within four months of age,” he said. So was the HIV-positive status of the baby a wrong diagnosis? More studies are therefore needed to confirm that the baby was indeed HIV-positive when ART was initiated just 30 hours after the birth and continued till the age of 18 months. The only way to distinguish a mother’s HIV particles from that of a baby is by comparing their viruses by doing a genetic analysis.
But the biggest weakness of the study appears to be the absence of the mother’s antibodies in the baby’s blood after some time. Mothers can infect the babies with HIV anytime during pregnancy but mostly in the last few days. Antibodies develop soon after infection. “Even if the baby was cured of HIV, we expect the mother’s antibodies also to be present in the infant up to 18 months,” Dr. Kumarasamy said. “This greatly weakens the study finding.”
The absence of antibodies to HIV was not disclosed to the press by the researchers when the results of the study were reported on March 3.
According to the abstract of the paper, the HIV-positive status of the baby was confirmed by HIV DNA and RNA testing on “two separate blood samples obtained on the second day of life.” Three “additional plasma viral load tests (days of life seven, 12 and 20) were positive before reaching undetectable levels at age 29 days,” the abstract states.
Apparently, HIV RNA has remained at “undetectable” levels on 16 different measurements obtained between one and 26 months of age. This despite the discontinuation of treatment at 18 months. HIV DNA copies also came down to four copies per million peripheral blood mononuclear cells present at the age of 26 months.
This led the researchers to conclude that the Mississippian baby was the “first well-documented case of functional cure in an HIV-positive child.”