Third patient is cured of HIV

Subject: Science and technology

Section: Health

Concept:

A 53-year-old man from Germany, referred to as the Dusseldorf patient, has become at least the third person to have been “cured of HIV” with the virus not being detectable in his body.
This was achieved with a bone-marrow transplant from people carrying a specific HIV-resistant genetic mutation ( CCR5-delta 32 mutation).
The CCR5-delta 32 mutation prevents the receptors used by the HIV virus from forming on the surface, effectively denying the virus its doorway to the body. It is this genetic mutation that scientists have utilised to “cure” patients of HIV.

About CCR5 Delta 32:

Cysteine-cysteine chemokine receptor 5 (CCR5) is a protein on the surface of white blood cells that are involved in the immune system as it acts as a receptor for chemokines.
CCR5 is found in the cell membranes of many types of mammalian cells, including nerve cells and white blood cells.
In humans, the CCR5 gene that encodes the CCR5 protein is located on the short (p) arm at position 21 on chromosome 3.
The role of CCR5 is to allow entry of chemokines into the cell—chemokines are involved in signalling the body’s inflammation response to injuries.

How does the mutation work in HIV patients?

Various mutations of the CCR5 gene are known that result in damage to the expressed receptor.
One of the mutant forms of the gene is CCR5-delta 32, which results from the deletion of a particular sequence of 32 base pairs.
HIV (Human Immunodeficiency Virus) mainly attacks the CD4 immune cells in the human body, thereby reducing a person’s ability to fight off secondary infections.
The CCR5 receptors on the surface of the CD4 immune cells act as a doorway for HIV. However, the CCR5-delta 32 mutation prevents these receptors used by the HIV from forming on the surface, effectively removing the doorway.
Prevalence :
Only 1 per cent of the people in the world carry two copies of the CCR5-delta 32 mutation(they got it from both their parents) and another 20 per cent carry one copy of the mutation, mainly those of European descent.

Can such transplants solve the HIV crisis?

With the mutation existing in very few people and nearly 38.4 million people living with HIV across the world, it would be very difficult to find a matching donor in the first place.