Editorial • Volume 386, No. 9999, p1109, 19 September 2015
On Sept 5, The Lancet was alerted by a UK Government source to the impending publication of a Nature paper allegedly about the possible transmission of Alzheimer’s disease. The source was anxious about the likely media coverage and the potential for a public health scare. Although the UK’s Science Media Centre was involved in helping to communicate the findings reported in the paper accurately, our source urged us to consider what we might do to reduce further the risk of a scare. We wrote to the Science Media Centre, explaining our understanding of the potential alarm and asking if we could help in some way. The Science Media Centre did not think the paper by John Collinge and Sebastian Brandner was unduly alarmist. It noted that several highly experienced press officers were working hard on the communication of the research findings to prevent any possibility of a scare. They added that if there were alarmist headlines, it would not be for the want of trying to prevent them.
On Sept 10, the UK newspapers took a very different angle than predicted, or hoped for, by our colleagues at the Science Media Centre. Ranging from “Alzheimer’s may be a transmissible infection” in The Independent to “You can catch Alzheimer’s” in The Daily Mirror or “Alzheimer’s bombshell” in The Daily Express, the general tone of the headlines was indeed deeply alarmist. Some news sources tried to redress the harm done. The BBC ran a story on its website saying there was “No evidence to support the headlines”. Meanwhile, in many other countries, the story was either not covered at all, or news headlines at least included a question mark.
Question marks were wise and judicious additions, if one reads what the published study actually showed (and did not show). The title promises “Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy”. But the study does not provide evidence of human transmission, as the authors acknowledge themselves in their final paragraph—”there is no suggestion that Alzheimer’s disease is a contagious disease and no supportive evidence from epidemiological studies that Alzheimer’s disease is transmissible.” What John Collinge and Sebastian Brandner’s elegant autopsy study of eight patients shows is that some patients treated with cadaveric human growth hormone who subsequently developed iatrogenic Creutzfeldt-Jakob disease also showed evidence of amyloid β deposition in their pituitary glands. The study does not show whether these patients would have actually developed Alzheimer’s disease had they lived longer (they died from Creutzfeldt-Jakob disease and they had no sign of tau protein pathology characteristic of Alzheimer’s disease). The study does not demonstrate that these patients’ amyloid β deposits were caused by growth hormone contaminated with “amyloid β seeds”. As the authors state in the paper, “Analysis of any residual archival batches of c-hGH [cadaveric-derived human growth hormone] for both prions and Aβ [amyloid β] seeds might be informative in this regard”—informative, and actually crucial to support their hypothesis. Controlled experiments injecting cadaveric human growth hormone into animals to discover whether amyloid deposits develop as a consequence are also needed to support their theory.
The much overused phrase “paradigm shift” was quoted in some news reports. But the findings, although certainly interesting, were a long way from a true “paradigm shift”. The use of this phrase likely heightened the interest and attention of journalists—and headline writers. Was “Evidence for human transmission” an appropriate title for this paper? The report does not describe human transmission of amyloid pathology. Rather, it reports amyloid pathology in patients with iatrogenic Creutzfeldt-Jakob disease. Therefore, such a strong statement in a title also seems misleading and potentially alarmist. Neuropathology experts, including those selected by the Science Media Centre, were left with the difficult task of balancing plausible explanations against tenuous extrapolations. The public ended up being warned about “Alzheimer’s link to blood transfusions” or “You can catch Alzheimer’s”, thereby generating unnecessary anxiety and potentially diminishing years of effort against patients’ stigmatisation.
Taking these events together, this episode of scientific reporting was handled poorly. One senior protagonist in this affair felt “upset and bewildered” by the outcome. Despite the best efforts of some, the system in place to assist science journalists broke down through a mix of inattention and perhaps even complacency. Preventive actions by the UK’s public health authorities were too weak and too late. The lesson that might be learned from this episode is that goodwill and hope are insufficient to prevent a public health scare.
- provided by : The Lancet