Geneva HIV patient cured? Can stem cell transplant help?

Source: The post is based on the article “Geneva HIV patient cured? Can stem cell transplant help?”  published in Indian Express on 25th July 2023

What is the News?

A sixth person with HIV, being referred to as the Geneva patient has likely been cured of HIV after receiving a stem cell transplant for leukemia. 

What is Stem Cell Transplant?

Stem cells are special human cells that are able to develop into many different cell types. 

Stem cell transplantation (SCT) , sometimes referred to as bone marrow transplant (BMT) is a procedure in which a patient receives healthy stem cells to replace damaged stem cells.

How was Stem Cell Transplant used in Geneva HIV patient?

The Geneva patient had been living with HIV since the 1990s and underwent a stem cell transplant in 2018 for an aggressive form of leukemia. 

One month after the transplant, his doctors found that there was a significant reduction in the number of HIV-infected cells.

Twenty months later, his tests did not find any viral particles, latent reservoirs of the infection, or elevated immune response against the HIV virus.

However, unlike the five previous cases of remission, the Geneva patient’s cells continue to be susceptible to HIV. 

Which genetic mutation is associated with lower risk of HIV?

People who inherit CCR5 delta 32 mutation are associated with lower risk of HIV (CCR5 delta 32 mutation mainly occurs in Caucasians).

This is because HIV lowers immunity in infected individuals by attacking the CD4 immune cells. However, to gain entry into these cells, it needs receptors on the surface. 

But people who inherit the CCR5 delta 32 mutation from both sets of parents do not form these receptors, essentially locking the virus out of the cells. Even those who inherit the mutation from one of the parents have fewer receptors and are also less likely to get the infection.

Can stem cell transplant become routine treatment for HIV?

It is highly unlikely. There are 38.4 million people living with HIV currently and it would be impossible to find a matching donor for all of them.

Besides, stem cell transplantation is a major procedure and comes with its own risks including the risk of the patient rejecting the donor cells. Even with the transplants, the virus may learn to infect cells through other mechanisms.

Instead, treatment of HIV across the world depends on effective antiretroviral therapy. This therapy suppresses the replication of the virus within the body, allowing the number of CD4 immune cells to bounce back. It also reduces the viral particles to undetectable levels, meaning the person can no longer transmit the infection to others. However, the anti-retroviral therapy needs to be taken for life.