Wednesday, 12 December 2012

The HIV Virus: A Possible Cure for Leukemia?

In April 2012, 7-year-old Emily “Emma” Whitehead was in the fight of her life following her second relapse of acute lymphoblastic—or lymphocytic—leukemia (ALL). The then 6-year-old’s parents and doctors turned to an unlikely source to save the young girl's life—the HIV virus.
Emma, diagnosed with ALL in 2010, underwent an experimental procedure involving a disabled form of HIV, the virus that causes AIDS, after two unsuccessful courses of chemotherapy failed to achieve sustained remission. The treatment, pioneered at The Children's Hospital of Philadelphia, is similar to therapies being developed at other cancer centers around the U.S.

"Training" Cells to Kill Cancer

Emma is one of a handful of patients with advanced leukemia to receive the CT019 therapy (formerly called CART 19 therapy), an experimental treatment that involves doctors reprogramming a person’s T-cells—a type of white blood cell that plays a key role in the immune system—to search out and kill cancer cells.
The experimental technique relies on help from a disabled form of HIV because the virus is adept at carrying genetic material into T-cells so they’re able to kill off cancer cells. Those genetically altered T-cells go to work attacking cells in the body that play a role in the development of leukemia.
It's important to note that the T-cells are removed from the patient before being bioengineered with the HIV virus. The patient is not injected with the virus. This treatment differs from chemotherapy, a drug that is one of the most common treatments of leukemia, which kills off all fast-growing cells in the body.

Emma's Remission

Three weeks after receiving the treatment at Children’s Hospital of Philadelphia, a bone marrow test revealed Emma had achieved remission. Today, she’s still in remission and thriving, but her doctors caution the remission needs to be sustained for a few years before using words like “cured.”
Regardless, the pharmaceutical industry is hopeful. In a statement, Hervé Hoppenot, the president of Novartis Oncology, called the research “fantastic” and said it had the potential—if the early results held up—to revolutionize the treatment of leukemia and related blood cancers. Researchers hope similar therapies that involve the reprogramming of a patient’s immune system, may also eventually be used to fight cancerous breast and prostate tumors.

Feeling Bad to Get Better

Ironically, a sign the experimental treatment is working is the patient feeling worse. Raging fever and chills are a sign the T-cells are doing their job and frightening drops in blood pressure can also be a side effect.
Emma experienced extreme symptoms to the treatment; she spiked a fever of 105 and wound up on a ventilator. Doctors deployed another unlikely remedy to treat her—a drug used to treat rheumatoid arthritis that stabilizes the impact the T-cells have on the immune system.
Within hours, Emma showed signs of improving, and a week after the treatment she awoke in the intensive care unit to celebrate her 7th birthday.
In patients with lasting post-treatment remissions, the altered T-cells live on in the bloodstream, though in smaller numbers than when they were fighting the disease. Researchers report some patients having a small number of the cells for years.

 ALL By The Numbers
The bone marrow in healthy kids makes immature blood cells (called stem cells) that become mature blood cells over time. The National Cancer Institute says childhood acute lymphoblastic leukemia is a type of cancer in which the bone marrow makes too many immature white blood cells. When a child has ALL, all those immature white blood cells don’t function like healthy cells, making it tough for the body to fight infection.
This type of cancer usually gets worse quickly if untreated and is the most common type of cancer in children.
In the United States, about 3,000 children each year are diagnosed with ALL. The disease can develop in children of all ages, as well as adults, but typically it occurs in patients 3 to 5 years old.

The Symptoms of ALL

The National Cancer Institute says these are the most common symptoms of childhood ALL:
  • Fever.
  • Easy bruising or bleeding.
  • Petechiae (flat, pinpoint, dark-red spots under the skin caused by bleeding).
  • Bone or joint pain.
  • Painless lumps in the neck, underarm, stomach, or groin.
  • Pain or feeling of fullness below the ribs.
  • Weakness, feeling tired, or looking pale.
  • Loss of appetite.
Other conditions may cause the same symptoms so it’s best to check with your child’s doctor if your child has any of the above symptoms, or other worrisome health issues.

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