Alzheimers disease, a neurodegenerative condition affecting millions worldwide, has long been considered a result of various genetic and environmental factors. However, a recent study published in Nature Medicine challenges conventional wisdom by presenting what could be the initial evidence that Alzheimer’s may have been transmitted from person to person in the past.
Unveiling the Historical Connection with Human Growth Hormone
The research delves into the aftermath of a medical practice prevalent from 1959 to 1985, where human growth hormone (hGH) derived from deceased donors’ brain tissue was administered to patients for various conditions. The investigation, triggered by the discovery that recipients of this hGH developed Creuztfeldt-Jakob disease (CJD), a rare prion-induced dementia, reveals an unexpected link to Alzheimers disease.
Assessing the Present-Day Risk and Implications
While the transmission of Alzheimer’s through donated hGH is deemed a historic phenomenon, concerns arise about the current risk. With hGH production now synthetically conducted in laboratories, eliminating the use of human tissue, the mode of transmission identified in the study is no longer applicable. However, the findings prompt a closer look at the potential long-term impact on those who received donated hGH before 1985.
The study’s authors scrutinized the cases of individuals who underwent hGH treatment during the specified period, discovering five recipients who later developed early-onset Alzheimers disease. Their analysis dismisses alternative explanations, indicating that donated hGH is a plausible link to the transmission of Alzheimer’s. As Alzheimer’s is significantly more widespread than CJD, the researchers suggest a heightened risk for those who received donated hGH, emphasizing the need for ongoing scrutiny.
Abnormally Folded Proteins—Amyloid and Tau—in the Brain
Alzheimers disease is characterized by the presence of abnormally folded proteins—amyloid and tau—in the brain. The study proposes a potential similarity in the transmission patterns between Alzheimer’s and prion diseases, offering a plausible explanation for the observed link. However, considering that amyloid protein deposits in the brain may precede clinical Alzheimer’s by two decades, a substantial time lag is anticipated before the impact of donated hGH on Alzheimer’s cases becomes apparent.
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