Stem Cells: Test Your Knowledge

New stem cell treatments have to be tested for safety and effectiveness -- even if they're your own stem cells. Here are some of the FDA's concerns: Will stem cells migrate to other parts of the body, will they make inappropriate cell types, and do they carry any tumor risk? Researchers are studying all of that.

For decades, doctors have used stem cells taken from bone marrow to help treat some cancers (such as leukemia), blood diseases (such as sickle cell anemia), and immune system diseases. Sometimes those stem cells come from the patients themselves. Other times they come from donated bone marrow. Either way, those are widely accepted stem cell treatments.

 Researchers are working on this. But that work is still in the early stages. That also goes for type 1 diabetes, stroke, and other conditions -- stem cell treatments are being studied, but those studies are still mostly focused on making sure the treatments are safe. Proving that they work comes after that.

Stem cells are all about potential -- they could make new cells to replace damaged ones, for instance. Some stem cells can make more types of cells than others, but what they all have in common is that they can do more than make copies of themselves. That means they have possibilities that most cells in the body lack.

There are stem cells throughout your body. They're not that easy to find, though. Even in bone marrow, a relatively rich source of stem cells, only about 1 in 10,000 cells -- or fewer -- is thought to be a stem cell. So yes, they're around. But think, needle in a haystack.

Stem cells aren't being tapped to cure the common cold. Colds are about viruses that invade your body -- and stem cells don't tackle viruses. Even if stem cells could snuff out the common cold, that wouldn't be a reasonable approach, since colds don't last long and aren't life-threatening.

Scientists can reprogram ordinary cells, such as skin cells, to act like stem cells. Those cells, called induced pluripotent stem cells (IPSCs), are being studied to check their safety.

Adult stem cells are actually found in infants and children, as well as adults. The three main types of stem cells are adult stem cells, embryonic stem cells, and induced pluripotent stem cells (IPSCs), which are ordinary cells (such as skin cells) that scientists have tweaked to act like embryonic stem cells.

In the U.S., human embryonic stem cells can only be used for research if they:

• Came from embryos developed through IVF (in vitro fertilization) procedures done for reproductive purposes,
• Are no longer needed by the people who got those IVF procedures,
• Were donated with those people's consent,
• And were not paid for in any way.

It's an option, but it's up to each family.  When a baby is born, the umbilical cord and placenta are routinely discarded, unless the parents chose to have blood from the umbilical cord or placenta collected. 

If you do, you could donate it to a public cord blood bank, store it in a family (private) bank, or have it saved for a sibling who has a medical need.  The American Academy of Pediatrics supports cord blood donation when banked for public use, but discourages the use of private storage of cord blood as "biological insurance."