HIV, immunodeficiencies and cancer: strengthening children’s immune defences | Children's Charity

HIV, immunodeficiencies and cancer: strengthening children’s immune defences

This research was completed on 6 September 2017

Published on 25 October 2014

Some children have weakened immune systems, making them vulnerable to infection and putting their lives at risk. This includes children with HIV, and children with severe immunodeficiencies and some blood cancers who need a stem cell transplant to restore their immune system. Although treatment helps strengthen the immune system, some children remain unusually susceptible to infection. Professor Robin Callard, of University College London’s Institute of Child Health, is investigating why. His findings could enable doctors to identify the best possible treatment for each individual child, so they have the highest possible chance of escaping infection and remaining healthy.

How are children’s lives affected now?

“Our immune system protects us from infection,” says Professor Callard. “Cells called T cells play a central role. Most of us have a huge repertoire of more than 10 million different T cells. This enables our immune system to recognise and destroy the many different viruses, bacteria and parasites that we might be exposed to throughout our lives,” says Professor Callard.

The diversity in our T cell population is important, because cells that recognise the chicken pox virus, for example, would not necessarily recognise the measles virus.

Unfortunately, some children have greatly reduced numbers of T cells, meaning they are more susceptible to infection. This includes children with HIV and children who have had stem cell transplants for some cancers or severe immunodeficiencies.

“Successful treatment can return T cell numbers to normal,” says Professor Callard. “However, it’s unclear what sort of treatment is best at restoring the diversity in the T cell population. Without that diversity, children remain vulnerable to infection.”


How could this research help?

Professor Callard aims to improve the long-term health of children with HIV, and children who are undergoing stem cell transplants, who have weakened immune systems.

“We are studying how children’s immune systems respond to treatment, using blood samples from around 1,000 children from the UK, Europe and Africa,” says Professor Callard. “We are assessing how the number of T cells increases with different approaches to treatment and whether the diversity in the T cell population is restored. Both factors are important.”

“Our findings could enable doctors to identify the best possible treatment for each individual child,” continues Professor Callard. “They may reveal, for example, how old children with HIV should be when starting antiviral treatment, the most appropriate drugs to use, and whether it helps to take a break from treatment. The ultimate goal is to optimise the long-term health of the immune system, giving children protection from infectious diseases throughout their lives.”

Project LeaderProfessor Robin E Callard PhD BA(maths) DSc
Project team
  • Professor Nigel Klein PhD FRCPCH
  • Dr Mike Hubank PhD
  • Professor Paul A Veys MB BS FRCP FRCpath FRCPCH
LocationGreat Ormond Street Hospital for Children, London
Other locations
  • Bone Marrow Transplantation, Great Ormond Street Hospital for Children NHS Trust
Duration2 years
Grant awarded25 July 2014
Start date7 September 2015
End date6 September 2017
Grant amount£137,569.00
Grant codeGN2263

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