Animal research plays a major role in many important medical advances, and yet many lay people do not seem to realize this. Why? Because whenever a new medical advance is announced, typically the end product of curing human beings is widely reported, with little background on the numerous animal experiments that led up to the human application.

The BBC reported this week, for example, that researchers believe they have successfully treated an 18-month-old British boy for severe combined immunodeficiency (SCID).

SCID is an immune system disorder that affects as few as 1 in 50,000 to 100,000 live births. It is characterized by a severe lack of immunity requiring those born with it to live in sterile conditions. SCID was famously depicted by John Travolta in the television film, \”The Boy in the Plastic Bubble.\”

The typical treatment for SCID is a bone marrow transplant, but in this case a donor was simply unavailable within the time frame needed. So the young boy became the third person in the world to receive a gene therapy treatment in an attempt to cure the disease. Two other patients received the gene therapy treatment at a hospital in France in 2000.

SCID is caused by a defect in a single gene which makes it a bit easier to tackle. Doctors removed bone marrow from the boy, and then used a virus to carry a copy of the unmutated gene into the marrow. They then reimplanted the marrow into the boy where it began producing cells to fight of disease. The boy\’s immune system is currently generating a normal amount of white blood cells.

The doctor who treated the boy told the BBC,

We\’re very excited by this — he was incredibly sick, with a nasty pneumonia, a life threatening infection. After his gene therapy, he was running around at home — he\’s a little boy now.

How did researchers develop this innovative gene therapy? Largely by proving that their technique would work in mice.

Using a modified form of a virus that causes leukemia in mice, researchers demonstrated that they could deliver the gene to bone marrow cells in mice.

Once it was proven to work there, researchers in France then used this mouse virus to successfully treat the bone marrow of two patients there. The British got non-human primates involved — they took the mouse virus and coated it in a protein from a virus that infects gibbons in an effort to make it more effective.

Whether or not this gene therapy approach will offer these patients a life time of immune protection is not known. But at the very least it will dramatically increase their life expectancy and quality of life. Thanks to animal research.

Sources:

\’Bubble boy\’ saved by gene therapy. The BBC, April 3, 2002.

The journey begins: The clinical trials for ADA-SCID. The New Healers, William R. Clark.

\’Bubble Boy\’ in Britain Cured Using Gene Therapy. Stephen Pincock, Reuters, April 3, 2002.