Alzheimer’s cases tied to no-longer-used medical procedure

Original Article ↗ Hacker News Discussion ↗

Researchers have reported rare cases of Alzheimer’s-like disease in adults who, as children, received human growth hormone extracted from cadaver brains, a practice banned in the 1980s after it was found to transmit Creutzfeldt‑Jakob prion disease. Commenters explore what this suggests about Alzheimer’s mechanisms—particularly amyloid and tau “prion‑like” proteins—while stressing that the condition is not contagious through normal contact and that the implicated treatment is obsolete. The conversation widens to concerns about disease transmission via transplants and blood products, and to how such findings might reshape research into neurodegenerative disorders.

Nature of the finding and risk framing

  • Thread centers on cadaver‑derived human growth hormone (c‑hGH) used 1959–1980s, later banned after causing Creutzfeldt‑Jakob disease (CJD).
  • New work links that same treatment to rare, likely “transmitted” Alzheimer’s‑like pathology via contaminated brain proteins.
  • Commenters emphasize:
    • Procedures and products in question are no longer used.
    • Study does not imply Alzheimer’s is contagious in everyday contact.
  • Debate over headlines: some see “transmitted Alzheimer’s” as alarmist; others say the more cautious titles bury the main scientific point.

Amyloid, tau, and prion‑like mechanisms

  • Several connect this to the beta‑amyloid (and tau) hypotheses: the finding supports a brain‑protein “seeding” model, but doesn’t distinguish amyloid vs tau.
  • Some argue amyloid plaques may be a symptom, not the primary cause; drugs that reduce amyloid have had limited benefit.
  • Others note rising evidence for misfolded proteins spreading in a prion‑like fashion in Alzheimer’s, Parkinson’s, ALS, etc., though “true” prions (like classic PrP) are still rare and hard to prove.

Is Alzheimer’s infectious?

  • One side: epidemiology (e.g., spouses not clustering in cases) argues against a straightforward infectious/prion disease.
  • Others say slow progression and incomplete surveillance could hide subtle transmission routes.
  • Alternative hypotheses mentioned: viral (especially HSV), bacterial, metabolic, or multiple independent pathways.

Medical procedures and transmission risk

  • Concern about prion‑like contamination via surgical instruments, especially in neurosurgery and dentistry; prions resist standard sterilization. Evidence here is mostly anecdotal or speculative.
  • Discussion of higher Alzheimer’s incidence in some medical professions and caregivers is raised but noted as inconclusive.

Blood, grafts, and other biological transfers

  • Broader worries about what is transferred via blood transfusions and cadaver grafts (ligaments, bone, gums).
  • Rare but documented transfer of allergies via transfusion is discussed.
  • Most agree these risks are outweighed by the immediate life‑saving benefit, and modern practice increasingly avoids unnecessary transfusions.

Interpretation and skepticism

  • Some see the cases as strong evidence for a protein‑seeding mechanism; others call them a suggestive but limited “one pathway among many.”
  • Debate over using Occam’s razor in complex biology: some think it argues against multi‑cause stories; others say biological systems routinely violate simple explanations.