UCLH Charity

Researchers from University College London (UCL) and UCL Hospital (UCLH) have identified five cases of Alzheimer’s disease (AD) associated with a medical treatment used decades earlier. The study is the first to report evidence of AD, which has been medically acquired from the cadaver-derived human growth hormone (c-hGH), transmitting amyloid-beta protein. Currently affecting 900,000 people in the UK, AD is a progressive neurodegenerative disease involving parts of the brain that control thought, memory and language. The now-banned treatment, c-hGH, was extracted from the pituitary gland of deceased donors and was used between 1959 and 1985 on at least 1,848 people in the UK. It was banned due to concerns that it was responsible for transmitting Creutzfeldt-Jakob disease (CJD), a rare, fatal condition that affects the brain. In 2018, archived samples of c-hGH were revealed to be contaminated with amyloid-beta protein, suggesting that individuals exposed to the contaminated c-hGH could eventually develop AD. Five of eight people referred to UCLH’s National Prion Clinic at the National Hospital for Neurology and Neurosurgery who had been treated with c-hGH in childhood, had symptoms of dementia, had already been diagnosed with AD, or met the diagnostic criteria for the condition and mild cognitive impairment. In two patients, biomarker analyses supported the diagnosis of AD and were suggestive of the condition in one other person after an autopsy analysis showed Alzheimer’s pathology. Additionally, “AD and some other neurological conditions share similar disease processes to CJD and [could] have important implications for understanding and treating AD in the future,” explained Professor John Collinge, director, UCL Institute of Prion Diseases and UCLH consultant neurologist. Despite AD not being transmittable between individuals, researchers say that their findings highlight the importance of reviewing measures to ensure there is no risk of accidental transmission of amyloid-beta. Collinge said: “The… transmission of amyloid-beta pathology in these rare situations should lead us to review measures to prevent accidental transmission via other medical or surgical procedures… in the future.”