A research team based mainly at the University of Virginia has announced the discovery of a new treatment for thousands of children who suffer from a hormone deficiency that restricts their growth.
The researchers report in today's edition of the New England Journal of Medicine that the growth rates of two abnormally short boys increased dramatically after they were injected with a laboratory-produced hormone over a six-month period.
Alan Rogol, a professor of pediatrics at the University of Virginia's School of Medicine in Charlottesville and a member of the research team that conducted the experiment, said the findings offer new hope for more than 20,000 prepubescent children in the United States whose brains fail to produce a normal amount of a growth-producing hormone.
Without treatment, Rogol said, these children often fail to grow even 4 1/2 feet in height.
He said the only current method of therapy is expensive injections with a somewhat scarce hormone that must be obtained from cadavers, although scientists are making advances in producing it synthetically.
Rogol said that while the children involved in the experiment showed "truly remarkable growth," widespread use of the treatment is still several years away. The university this week will begin tests with more children to determine in what doses and by what methods the drug can best be administered. Rogol said approval by the Federal Drug Administration is "at least a couple years off."
When the two children came to the university to be evaluated for the study, both were as tall as an average boy of 4 1/2 years of age, though one was 7 1/2 and the other was 9. The 7-year-old was growing at a rate of less than an inch a year and the 9-year-old at less than 2 inches a year. The average rate for children their ages, according to Rogol, is between 2 and 2 1/2 inches a year.
The boys were given injections of a hormone made in a laboratory at the Salk Institute in San Diego that stimulates release of the growth-producing hormone by the pituitary gland, located at the base of the brain. They carried two-week supplies of the hormone in pumps worn around their waists and received the injections automatically every three hours through needles inserted just under the skin in the abdominal area.
During the six-month period, the researchers reported, the 7-year-old grew at 6 1/2 times his previous rate. He gained almost 3 inches in height -- a "phenomenal" increase, according to Julia Reschke, a member of the research team. The 9-year-old, for reasons the researchers say are uncertain, grew more slowly -- slightly less than an inch and a half -- at a rate 1 1/2 times as fast as he had without the therapy.
According to Reschke and Rogol, only a small minority of short children suffer from a lack of the growth-producing hormone and can potentially benefit from the treatment.
For anyone past puberty, the experiment offers no hope, Reschke said in an interview.