Adolescents found to have strong immune response to HIV infection, may benefit from early treatment

April 12, 2000

Adolescents infected with the virus that causes AIDS have a surprisingly robust immune response and may benefit particularly well from aggressive early treatment with anti-HIV medications, according to a research team led by an immunologist at The Children's Hospital of Philadelphia. The study is reported in the April issue of the Archives of Pediatric and Adolescent Medicine.

Studying 270 HIV-infected and uninfected teenagers, the researchers measured the levels of T lymphocytes, cells that originate in the thymus gland and play important roles in the immune system. Among those cells, they found an unexpectedly higher number of CD8 naïve T lymphocytes in adolescents who had been infected with HIV, compared to uninfected adolescents. Naïve T lymphocytes are cells that have not been previously exposed to invading microorganisms, including HIV. "The high levels of naïve CD8 cells that we found suggests that these cells may be capable of mounting an immune response," said the study's lead author, Steven D. Douglas, M.D., Chief of Immunology at Children's Hospital, who added, "CD8 cells are major players in killing the virus."

The naïve T lymphocytes are produced by the thymus gland, which gradually shrinks after puberty, becoming less active in immune function during adulthood. "If the thymus continues to produce immune system cells in HIV-infected adolescents, the adolescent immune system may be stronger than previously thought," said Dr. Douglas. "With aggressive use of current medications, we may be able to rebuild immune systems in HIV-infected adolescents."

Adolescents represent the fastest growing segment of the U.S. population newly infected with HIV; a 1996 White House report estimated that a new infection occurs every hour of every day. However, because of the long incubation period before symptoms appear, relatively small numbers of HIV-infected teenagers are aware of their infection and receiving medical care for it. Another complicating factor is the social situation of many infected adolescents, which may leave them with inadequate access to the health care system.

"Although HIV infection has been moving into adolescents, relatively little is known about the specifics of how adolescents' immune system respond to the virus," says Bret Rudy, M.D., medical director of the Adolescent AIDS Initiative at Children's Hospital, and a co-author of the study. The current study builds on earlier work by Drs. Douglas and Rudy, who recently published the first reference measurements for cells that act as immune system markers for both HIV-infected and healthy adolescents.

The current standard of treatment for controlling HIV infection is called highly active antiretroviral therapy (HAART), a combination of drugs that interfere with the virus' ability to replicate. "Because of their robust immune systems, HIV-infected adolescents may be the best candidates to benefit from aggressive drugs such as HAART," says Dr. Rudy. "However, it's imperative for individuals to become aware of their infections before they actually become sick, because early treatment may give their immune systems the best opportunity for a strong response." Dr. Rudy is co-chair of Project ACCESS, a social marketing campaign aimed at educating at-risk youth about the importance of HIV counseling and testing.

The current study was co-sponsored by the National Institute of Child Health and Human Development, the National Institute of Allergy and Infectious Diseases, the National Institute of Drug Abuse, the National Institute of Mental Health, and the Health Resources and Services Administration. Blood samples were drawn from adolescents at 16 clinical sites throughout the United States participating in the Adolescent Medicine HIV/AIDS Research Network, established by the National Institutes of Health and the Health Resources and Services Administration. Further studies will be conducted on how the immune system of adolescents responds to HIV infection over a period of time.
-end-
The Children's Hospital of Philadelphia, the nation's first children's hospital, is a leader in patient care, education and research. This 373-bed multispecialty hospital provides comprehensive pediatric services, including home care, to children from before birth through age 19. The hospital is second in the United States among all children's hospitals in total research funding from the National Institutes of Health.

Children's Hospital of Philadelphia

Related Immune System Articles from Brightsurf:

How the immune system remembers viruses
For a person to acquire immunity to a disease, T cells must develop into memory cells after contact with the pathogen.

How does the immune system develop in the first days of life?
Researchers highlight the anti-inflammatory response taking place after birth and designed to shield the newborn from infection.

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.

Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.

COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.

Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.

Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.

Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.

How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.

Read More: Immune System News and Immune System Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.