Growth Hormone Treatment May Have Transmitted Alzheimer’s to Children, Study Warns

A now discontinued hormone therapy that contained contaminated cadaver tissue may have transmitted degenerative brain disorders to patients.

Alzheimer’s disease and other degenerative brain disorders that are normally inherited or develop sporadically later in life may be transmissible in certain circumstances, according to the findings of new research.

A team of U.K. researchers from the National Hospital for Neurology and Neurosurgery and the UK Dementia Research Institute at UCL in London indicate patients who received contaminated growth hormone treatments as children may be at risk of developing Alzheimer’s disease, dementia, or other symptoms seen among those with neurodegenerative disorders.

Alzheimer’s disease progressively destroys brain cells and tissue, which causes deterioration of memory, thinking, and social skills. The widespread and degenerative disease is the most common form of dementia, or memory loss, and eventually interferes with daily functioning.

In this new study, researchers indicate that between 1959 and 1985, at least 1,848 patients in the United Kingdom were treated with human growth hormones extracted from the pituitary glands of deceased donors, known as human cadaveric pituitary-derived growth hormone (c-hGH). Patients received these hormone injections several times per week, over the course of several months or years, to treat severe short stature and other conditions caused by hormone deficiencies.

The treatments were discontinued in 1985, after at least one patient treated with c-hGH died from iatrogenic Creutzfeldt–Jakob disease (iCJD), a rare but rapidly progressive and degenerative brain disease that is acquired when infectious brain proteins are accidentally transmitted to patients during medical or surgical procedures that use cadaveric tissue.

Researchers later tested archived batches of the c-hGH treatments and found they were contaminated with measurable quantities of AB seeding; precursors to developing Alzheimer’s disease.

According to findings published this week in the medical journal Nature Medicine, at least 200 cases of iCJD have been reported worldwide as a result of the contaminated treatments.

Cognitive Impairment Linked to Growth Hormone Exposure

The researchers analyzed the medical history of eight individuals treated with c-hGH injections during different stages of childhood, who were referred to the National Prion Clinic (NPC) in the UK, which studies those diagnosed or at risk of developing brain diseases from the therapies.

At least five patients exhibited symptoms consistent with those seen with early-onset dementia, including progressive cognitive impairment, which developed between 38 and 55 years of age, between three and four decades after c-hGH exposure. Three of the five patients had been diagnosed with Alzheimer’s disease prior to be being referred to the clinic, and the other two patients presented symptoms seen among those with the disease, including memory loss, trouble communicating, and changes in behavior or personality.

Researchers reviewed brain scans of the patients, which showed progressive loss of brain tissue volume that are consistent with neurodegenerative diseases. Three of the eight study participants died, and autopsies revealed accumulations of infectious AB deposits in the brain, similar to those seen among those suffering from Alzheimer’s disease.

Genetic testing ruled out any potential genetic factors for developing adult-onset brain disorders, and the patients’ ages meant sporadic early-onset was unlikely, leading researchers to determine the new and progressive cognitive disturbances seen among the patients were the result of repeated c-hGH exposure. Among the study participants, at least four c-hGH recipients were diagnosed with confirmed Alzheimer’s disease, five met the standard definition for dementia, two with a clinical diagnosis of dementia were suspected to also have Alzheimer’s, and one had mild cognitive impairment, according to the findings.

The findings suggest Alzheimer’s disease can be transmitted in certain circumstances, such as during medical procedures. While there is no evidence that it can be transmitted to others during daily activities, researchers indicate further studies are needed to analyze exactly how this disease spreads. Researchers also indicate the findings warrant further preventative measures to avoid medically transmitted brain diseases, such as ensuring surgical instruments and other medical treatments are properly disinfected.