HIV doesn’t really have a positive connotation; in fact, if we play a word association game, what do we visualize or think of when we hear the word “HIV”? Automatically, I think of AIDS, and when I think of AIDS, I think of suffering and darkness. BUT HIV has actually shed light for a young girl named Emily Whitehead. Perhaps you’ve heard the story that has garnered much media attention: Emily, a 7-year old girl from Philipsburg, PA has been cured of Acute Lymphoblastic Leukemia (ALL) due to a break-through cell therapy that utilizes a modified form of HIV.
After relapsing two times, chemotherapy just wasn’t cutting it, no matter how intense the radiation was, and so researchers and doctors at the Children’s Hospital of Philadelphia (CHOP) took out the big guns and used this cell therapy called CTL019 to try to destroy the cancer.
So what exactly is happening on a cellular level?
Some background is in need perhaps.
What is ALL? ALL is the most common form of leukemia, the cancer of our white blood cells, in children. What happens is that the B cells in our immune system become cancerous, forming immature cells called blasts that cause damage by crowding out our healthy cells in the bone marrow and spreading to other organs. Our killer T cells in our immune system is responsible for finding pathogens in our body and killing them (thus the name killer T cells) BUT they cannot detect the cancerous B cells and so the leukemia cannot be destroyed by our immune system.
Usually chemotherapy is good at getting rid of ALL, but not for Emily, and so doctors resorted to the CTL019 treatment.
So basically what we want is for the T cells to be able to detect the cancerous B cells, so researchers used a modified form of HIV, called a lentivirus to inject into the T cells special receptors so that they will be able to recognize a protein that is only found on B cells called CD19. These cancerous B cells have that protein on them!
T cells are taken out of the patient’s body and reengineered to detect the CD19 proteins on the B cells, and once they detect them, they will kill them.
It worked marvelously for Emily but it wasn’t without side effects (because of this therapy, Emily suffered a huge increase in a protein associated with rheumatoid arthiritis!!).
But do you think that this break-through, this “cancer-vaccine” like therapy is worth the risk? Do you think we’ve reached a beginning point where patients do not have to suffer the painful effects of chemotherapy and bone marrow transplant?
Have we found a cure?
Only time will tell.