Growth Hormone Improved, Scientists Say
The natural human growth hormone that has been associated with the deaths of three people in the United States in recent months was manufactured before extensive improvements in the purification process were begun in 1977-78, researchers said Tuesday.
Reassurances of the improved safety of the hormone came after federal officials last weekend ordered a temporary halt to the distribution of the hormone to 150 physicians nationwide who use it to treat growth-deficient children.
All three of the deaths were individuals who, as youngsters, had received the hormone as treatment for their short stature. One of the deaths has been confirmed as due to Creutzfeldt-Jakob disease, a rare brain disorder believed to be caused by an infectious agent. According to authorities, the other two deaths also are suspected of being due to the same affliction.
Dr. Mortimer B. Lipsett, director of the federal agency that administers the hormone supply, said that as a safety precaution, distribution will be halted for six to 18 months while researchers conduct tests to make sure that current supplies do not contain infectious agents that are believed to be responsible for Creutzfeldt-Jakob disease.
“There is a big difference between the hormone that was manufactured prior to 1978 and the current one,” said Lipsett, who is director of the National Institute of Arthritis, Diabetes, Digestive and Kidney Disease in Bethesda, Md.
‘Greater Than 95% Pure’
“Before 1978 the material probably was no more than 35% hormone, the rest of it being contaminating protein,” he said. “Since 1978, the product is greater than 95% pure.”
Lipsett said that none of the approximately 10,000 youngsters currently under treatment has received any of the pre-1978 hormone.
In a letter that he sent to physicians dated April 19, 1985, the federal official said, “The weight of evidence suggests that there is no contamination of the current human growth hormone preparation from the National Hormone and Pituitary Program.”
According to Lipsett, the improvement in the purification process occurred in 1977-78 after a laboratory under the direction of Dr. Albert F. Parlow at Harbor-UCLA Medical Center became the sole manufacturer for the nation’s supply of the hormone.
“We cannot say with absolute certainty that the product is 100% safe, but no one can say that about any drug,” Parlow said Tuesday.
He said records show that the three individuals who died received hormone manufactured before 1977.
Dr. Gertrude Costin, director of the endocrine clinic at Childrens Medical Center of Los Angeles, said most of the reaction by parents to the halt in availability of the hormone has been that their child may now not gain his or her full height.
But Lipsett said there will be “essentially no difference” in the growth of children if the suspension lasts only six months. If the suspension lasts 18 months, some children, depending on their age, may lose some height, he said.
