Study: Contaminated injections may have caused Alzheimer's disease in 5 people health

Five patients in the United Kingdom developed Alzheimer's disease as a possible result of contaminated injections they received decades ago when they were still children. The cases were reported on Monday (29) in the magazine Natural medicine.

All of the people described in the article were treated in childhood with a form of human growth hormone extracted from the pituitary glands of deceased people (c-hGH, human growth hormone derived from cadavers, in English). This treatment was applied to more than 1,800 patients in the United Kingdom between 1959 and 1985, and was used for various reasons for short stature.

In 1985, treatment was discontinued after experts discovered that some batches of growth hormone C were contaminated with prions (infectious proteins) that cause Creutzfeldt-Jakob disease (CJD) in some people. The disease can cause dementia, muscle spasms, and a staggering gait, according to Medicine MSD Health Manual.

The c-hGH was then replaced with synthetic growth hormone, which carries no risk of transmitting the disease. But the researchers report that some patients diagnosed with Creutzfeldt-Jakob disease after treatment with contaminated injections also developed premature brain deposits of beta-amyloid protein — a structure that has been shown to be linked to Alzheimer's disease.

In 2018 research, scientists showed that archived samples of c-hGH were contaminated with beta-amyloid. Although stored for decades, they transmitted diseases to laboratory mice when injected.

The researchers suggested that people who received the contaminated injections but did not succumb to Creutzfeldt-Jakob disease and lived longer could eventually develop Alzheimer's disease.

Contaminated patients

In the new study, researchers from University College London (UCL) reported on the cases of eight people who were referred to the National Prion Clinic at the National Hospital for Neurology and Neurosurgery. All had been treated with c-hGH in childhood, and some had received injections over several years.

Five of these people showed symptoms of dementia and had already been diagnosed with Alzheimer's disease or at least met criteria for the condition; One individual also met criteria for mild cognitive impairment.

The group was between 38 and 55 years old when they began to develop neurological symptoms. The unusually young age suggests that the patients did not have the usual sporadic Alzheimer's disease associated with aging. Moreover, scientists ruled out the possibility that this disease was hereditary in the five individuals who underwent genetic testing.

Subsequently, biomarker analyzes confirmed Alzheimer's disease in two diagnosed patients and suggested Alzheimer's disease in another; Moreover, autopsy analysis showed the presence of the disease in a patient who had already died.

Since c-hGH treatment is no longer used, scientists believe there is no longer a risk of developing Alzheimer's disease from the injections. “The patients we describe received specific medical treatment that had long been discontinued, which involved injecting patients with substances that we now know are contaminated with proteins associated with the disease,” says lead author John Collinge, director of the UCL Prion Disease Institute. In the current situation.

“However, recognition of the transmission of amyloid beta pathology in these rare cases should lead us to review measures to prevent accidental transmission through other medical or surgical procedures to avoid such cases in the future,” says Collinge.

Scientists confirm that no case of Alzheimer's has been reported so far in medical, surgical or other routine care procedures.

“It is important to emphasize that the circumstances in which we believe these individuals tragically developed Alzheimer's disease are highly unusual, and to reinforce that there is no risk of the disease spreading between individuals or in routine medical care,” said co-author Jonathan Shute. Physician Director at Alzheimer's Research UK.