Painful blockages of arteries in the legs—called peripheral arterial obstructive disease, or PAOD—are less familiar than the ones that cut off blood flow to the heart, but they can be just as dangerous. Serious cases can lead to gangrene, kidney damage, stroke, and even death, but arterial bypass surgery or amputation rarely alleviates the condition. Now cardiologist Brian Annex of Duke University Medical Center has found a promising experimental treatment that might cure the disease with little more than an injection.
Annex and his colleagues focused on a gene that induces the body to grow new blood vessels around a blocked artery, a process called angiogenesis. The researchers injected this gene into rabbits with simulated PAOD. Soon the rabbits began producing proteins that triggered angiogenesis in the animals’ legs and halted the process of cell death that leads to gangrene. A few previous studies on animals have induced vessel growth with gene therapy, but this one provides a template for the next stage in the research: clinical trials on humans. One set of clinical trials is already under way at the National Institutes of Health, and another is in the works at Duke University.
Eight million to 12 million people in this country have PAOD; among the 250,000 with the severe form, up to 40 percent die within a year. “We’d love to improve on that,” Annex says.