To Heather, Happiness Is a Hormone Called Thymosin
Kindergarten is a big event in any child’s life. But when 5-year-old Heather entered a Sacramento kindergarten this fall, it signified a medical breakthrough that marks another turning point in the field of immunology.
Heather—her last name has not been made public at the family’s request—is one of about a thousand children so far diagnosed without a functioning thymus gland, which is located in the chest above the heart. This means Heather lacks a critically important hormone that accelerates the production of white blood cells to fight infection. Her life expectancy at birth was only six years.
But the dedicated teamwork of two California pediatricians and a Texas biochemist is changing the odds on Heather. She has become the first person to receive injections of thymosin, an extract from the thymus glands of calves—with dramatic results.
Until recently, Heather’s life was an agonizing and seemingly endless series of fevers, earaches, colds, flu, pneumonia and severe diarrhea. She was so frail that nurses at the University of California’s San Francisco Medical Center, where the child was being treated, nicknamed her Heather Mouse. Not surprisingly, Heather’s mother, a bank officer with Wells Fargo, fiercely guarded her daughter against contact with children who had so much as a case of the sniffles. The greatest threat: chicken pox, invariably a killer for children with severely impaired immunity systems.
Heather was first brought to Dr. Arthur Ammann, 38-year-old director of pediatric immunology at U.C. Medical Center, two years ago. She was, recalls Ammann, “tiny, pale and bloated. And she had been so sick she was a pretty irritable youngster.” Ammann and Dr. Diane Wara, 32, a fellow in pediatric immunology, turned to Allan Goldstein, director of biochemistry at the University of Texas medical school in Galveston. Goldstein had been following up on the work done by pioneers in immunology, Robert A. Good and J.F.A.P. Miller.
“Until 1961 everyone thought that the thymus was as useless as the appendix,” says Goldstein. “Then Good and Miller found that if they removed the thymus from newborn mice and rabbits, they died a wasting death.” Why? Apparently the thymus accounts for that half of the body’s immunity system which provides the most protection against diseases like cancer, dysentery, tuberculosis and even leprosy. Goldstein and Abraham White, chairman of the biochemistry department at Albert Einstein College of Medicine, set out to isolate the hormone. They began by grinding up the thymus glands of mice, then moved on to rabbits and eventually calves. In 1966, Goldstein and White published their first paper announcing the successful extraction of thymosin.
Once they received permission to treat Heather with the hormone, Drs. Ammann and Wara administered her first injections last April. “It took almost three weeks before Heather began to perk up,” recalls Wara. “Then we sent her home without the hormone to see how long the effects would last. Three weeks later, she came back with an earache.” The real test came last summer, when Heather contracted chicken pox. Recovery was prolonged, but complete.
Nine others—one youngster and eight adults—are now receiving thymosin shots, and there is hope that people with only partial deficiencies—including patients with Hodgkin’s disease and even breast cancer—may be helped by thymosin. In some cases it can have no effect. A 3-year-old Texas boy still lives inside a germ-free plastic bubble at Baylor University because his body is without certain bone-marrow cells on which thymosin must act.
Right now, Heather is looking forward to her sixth birthday and is happily showing off her first report card. “She looks terrific,” says Dr. Goldstein. “Like a normal child. This is what makes our work worthwhile.”