Creutzfeldt-Jakob Disease, Human Growth Hormone, and Its Replacement with Synthetic Growth Hormone
Recombinant DNA technology has enabled the production of human hormones. Development of the synthetic material has been accelerated most recently in reaction to reports of possible iatrogenic transmission of Creutzfeldt-Jakob disease (CJD). Seven recipients of human pituitary-derived growth hormone (hGH) died of CJD. The laboratory extraction process and preparation of hGH have undergone significant technological changes, primarily in the 1970s, thus significantly decreasing the likelihood of transmitting CJD. Rod-shaped structures which have been found to cross-react immunologically with scrapie protein have been found in CJD-affected brains. Since the middle of the 1980s, with the advent of recombinant DNA technology, synthetic human growth hormone has become available from various pharmaceutical laboratories around the world. Unfortunately, the newer synthetic growth hormone has not been without some medical complications and adverse side effects. Immunogenicity may be a problem, partly because synthetic growth hormones contain an extra methionyl residue as an amino acid terminal.