Do you care what happens to a baby's blood sample?
来源：未知 作者：谯律叽 时间：2019-03-01 02:08:09
By Peter Aldhous How would you feel about a sample of blood from your newborn baby being used in medical or forensic research without your knowledge? It’s been happening, with little comment, for years. But in two US states, parents and campaigners for privacy recently took health authorities to court for retaining their newborns’ blood, and using it for purposes they never agreed to. As the US Institute of Medicine prepares to hold a workshop to consider the controversy, New Scientist explores the ethical quandaries – and opportunities – of research using newborn blood-screening samples. Why is newborn blood taken at all? In all 50 US states – as in many countries worldwide – newborns’ heels are pricked to collect spots of blood that are tested for inherited conditions such as cystic fibrosis and phenylketonuria, or PKU. Where treatments are available, this allows doctors to intervene early to avoid serious disability: intellectual impairment caused by PKU, for instance, can be prevented if children are put onto a low-protein diet. “Screening is lifesaving or life-enhancing in many cases,” says Alan Fleischman, medical director of the March of Dimes Foundation of White Plains, New York, which works to promote infant health. That sounds reasonable. Why the fuss? The screening is mandatory. Given the health benefits, that may be justified. But in some states, cards with dried blood samples are retained for years, and later used for a variety of research projects. This is where the debate about consent gets heated. In Minnesota, parents who objected to the retention of their children’s blood samples teamed up with Twila Brase, a nurse who runs the Citizens’ Council on Health Care in St Paul, Minnesota, which wants to limit the role of government in medicine, to claim that the storage of samples and their use for research breached a 2006 law on genetic privacy. That case was eventually thrown out of court (PDF) last November. But the following month, health officials in Texas agreed to destroy some 5 million stored blood samples to settle a similar lawsuit. So should this be seen as a backlash against “big government” whipped up by “privacy extremists”? “That would be a grievous error,” says Ellen Clayton, a specialist in law and genetics at Vanderbilt University in Nashville, Tennessee. She argues that although some campaigners have wider political motivations, parents have every right to be told what the samples might be used for, and in some cases should be asked permission before research can go ahead. In the Texas case, for instance, it later emerged that several hundred of the samples had been transferred to the Armed Forces DNA Identification Laboratory, to help build a national forensic database. “I would not be surprised if parents might be less interested in having samples used for forensics than for health-related research,” says Wylie Burke, a bioethicist at the University of Washington in Seattle who will chair the Institute of Medicine workshop, to be held on Monday. In the US, where health insurance premiums can skyrocket if you are deemed at high risk of illness, parents may also fear that research projects could turn up information that will come back to haunt their children, if it was ever linked to their medical records. What sort of research is the stored blood used for? Some projects evaluate new screening tests. Without such evaluations, screening panels may include tests that are unreliable – or even harmful, given the psychological distress of being told your baby is sick. Screening for an enzyme deficiency called histidinemia, for instance, was abandoned after it was shown in the 1990s to be a relatively benign condition that didn’t respond to the special diet designed as a treatment. Other projects include searches for genes that predispose people to common disorders, and epidemiological studies of infectious disease. In the 1980s, for instance, studies of maternal antibodies to HIV in newborn blood samples helped raise the alarm about the spread of the virus. In 2003 the US Centers for Disease Control and Prevention and the Association of Public Health Laboratories conducted a survey of the research that different states did with such samples. Of the 46 states that responded, 34 had used the samples to evaluate newborn screening tests, while 13 had used them for other types of medical research (Journal of Pediatrics, vol 148, p 618). Few US states give details of the uses to which newborns’ blood samples are put, however, which is why many participants in next week’s workshop will call for greater transparency. In which cases should parents be asked for specific permission? There’s no consensus on this. Burke suggests that most projects other than the evaluation of screening tests may need specific informed consent. Others argue that there’s rarely a need to seek explicit permission as long as the samples are stripped of personally identifying information. And some scientists worry that asking for consent for every project will tie up important research in red tape. Could asking for parents’ consent reduce the number of blood samples available for research? The evidence suggests that people want to be asked before samples are used in medical research, but are generally willing to take part. For instance, last year a survey by the Genetics and Public Policy Center in Washington DC revealed that 90 per cent of US adults would worry about privacy if they provided samples to a “biobank” investigating the genetics of common disease. But 60 per cent said they would participate, if asked (American Journal of Human Genetics, vol 85, p 643). Surely there must be a simple way to give parents the choice about what happens to their children’s samples? Perhaps technology can help. Researchers at the University of Michigan in Ann Arbor are now testing an online system that could let parents select privacy settings to control how their children’s blood samples are used. Developed by a company called Private Access of Irvine, California, the system allows parents to specify what types of scientists – such as academics, or those working for local health agencies – can use the blood samples, whether they can also have access to medical records, and whether it is OK for researchers to contact the families for more information. More on these topics: