The Experts Speak: Challenges in Banking Brain Tissue for Research

Introduction

The acute shortage of human brain tissue to fuel the research that scientists, clinicians, and patient advocates say is necessary to advance the treatment of neurogenerative diseases is slowing scientific discovery. Brain biobanks play an essential role in accelerating the development of innovative neurotechnologies, yet remain limited in numbers, and narrow in their scope and the distribution of samples. Biobanking whole brains shares many common activities with the broader field of human tissue biobanking. Although both streams of biobanking ultimately aim to facilitate health and medical research, some aspects of brain banking are unique. These particularities of brain donation and banking present unique challenges for internal and external brain banking stakeholders.

First, whole brains are not able to be collected or stored through the same clinical pathway as other biobankable tissue, for example, remnants from surgical cancer removal, as specialist postmortem expertise and facilities are required for retrieval. This has both practical and governance implications for brain banks, affecting their ability to facilitate and access brains. To the public, the whole brain can be perceived as special or different than other bodily organs and tissue for potential donation for research. This can impact on the choice to participate in brain donation programs, particularly as the final choice to consent is generally reliant on third party family members. Finally, from a researcher perspective, the human brain displays greater functional and cellular heterogeneity, and more complex neural pathways relative to lower mammal brains. These characteristics can render alternative experimental resources less desirable and create a greater demand for whole brains.

We asked four brain banking experts to discuss their perspective on the same question: What are the most pressing challenges for brain banking in the current health and medical research landscape?

Starting with Ethical Legal and Social Issue (ELSI) challenges, Laura Siminoff likens the consenting process of brain donation for research to that of consent for organ donation for therapeutic transplantation, and discusses the factors that influence willingness to donate to a brain bank. Donor perspective experts Cassandra Griffin and Christine Paul advocate for an individualized and personalized approach to brain donation consenting discussions, and Anita Mahadevan provides a low- and middle-income country perspective, articulating brain banking challenges in India. Finally, brain banker and brain tissue researcher Greg Sutherland discusses the challenges of supplying brain tissue for researcher needs, and the evolving nature of these needs.

Address correspondence to:

Amanda Rush

Menzies Centre for Health Policy and Economics

Level 2, Charles Perkins Centre

The University of Sydney

Camperdown

NSW

Australia

E-mail: amanda.rush@sydney.edu.au

Challenges with ELSI Challenges

Brain banks share the same set of ethical and social challenges with biobanks that do not collect brains, in addition to some unique considerations. For all types of biobanking, the complexity and breadth of practices generate risks, benefits, and responsibilities that have yet to be adequately explicated or resolved nationally and internationally. No universal ethical guidelines exist for biobanks, but a multiplicity of concerns is identified in the literature.

These include unknown consequences to individual and familial donors from the analysis of potentially identifiable materials or information (especially genetic data), misconceptions about biobanking, a confusion about the linkage between research and medical care, and socioeconomic inequalities that can impinge on understanding and voluntariness. In particular, socioeconomic inequalities can be exacerbated by a consent process that is rarely tailored to populations with different communication needs.

In addition, the growing ability to generate big data material, including linkage of samples with medical records and whole genome sequencing, has brought about new ELSI challenges. These challenges will require a further consideration of the storage and security of data to protect the privacy of individual donors and families, including clear guidance for biobanks and researchers. Finally, advancements in artificial intelligence (AI) may also undermine confidentiality protections in the future.

ELSI challenges specific to brain banking arise from the brain's unique role as the center of human consciousness, and the limitations of obtaining samples from living persons requiring postmortem collection of whole brains. The consent environment is more akin to requests for organ and tissue donation for transplantation. Limited research has identified that even when individuals predesignate themselves as brain donors, it is met with opposition from family members, especially older Black or Latino individuals or low-income whites.

One study found that concerns and attitudes about brain donation fell into three categories: (1) concerns and misconceptions about brain research and the process of brain removal, (2) religious beliefs, and (3) the role of the family.¹ When families anticipated an open casket, there was greater concern about how brain removal might affect the appearance of the body, for example, whether incisions would be visible. As postmortem viewings continue to be a common funerary custom in the United States, even when the deceased are to be cremated, concerns about the appearance of the deceased are amplified because of the anatomical colocation of the face and brain.

Unfortunately, little public education has been provided concerning the impact of brain donation on desired funeral arrangements, especially the ability to have a viewing of the deceased. Separately, concerns about the privacy and confidentiality of brain donors can make brain donation more sensitive than other tissue type donations. This is because brain donors can experience stigma and financial disadvantage in connection to diseases of their brain (e.g., Alzheimer's disease (AD), schizophrenia).

Our own ELSI substudy as part of the Genotype-Tissue Expression Project (GTEx) initiative found that the majority (78%) of families who agreed to donation for organ and tissue transplantation would choose to donate the brain if given the opportunity.² In this study, unwillingness to donate the brain was associated with next of kin's unwillingness to donate their own tissues for research, concern with potential for-profit use of tissues, squeamishness about tissue donation, and belief that families who donate should have a say in how the donated tissues are used.¹

The GTEx experience was highly successful obtaining whole brain donations for biobanking and genomic research. Engaging experienced and skilled donation professionals employed by organ procurement organizations will be essential to continue normalizing brain donation within the framework of organ donation activities for solid organs and tissues. In return, the research community has an obligation to identify the special challenges and the ethical obligations of brain biobanking.

Specific considerations include research and brain banking governance so that participants can be informed of research outcomes, specifically those that are potentially actionable; the need to standardize procedures for blanket consent, withdrawal of consent, and opting out of research in the future; and very importantly, return of results, with possibilities for donors' families to choose to receive subsets of information. Making referrals and access to genetic counseling will be an imperative, and those who do not have insurance coverage should receive counseling gratis.

As we move forward with large-scale research projects requiring the accessioning of large numbers of brains and other cadaveric tissues from diverse racial and ethnic groups, we must address ethical and distributive justice concerns along with public and professional education efforts. With a consent process that is both respectful and instructive, it is possible to gain the support of most families asked for brain donation.

Address correspondence to:

Laura A. Siminoff

Laura H Carnell Professor of Public Health

College of Public Health

Department of Social and Behavioral Sciences

Temple University

1700N Broad Street, Suite 427

Philadelphia, PA 19122

USA

E-mail: lasiminoff@temple.edu

Considering the Prospective Donor Perspective

As brain donation programs increase in number, so too does the need to understand the human experience of these protocols. The limited available literature suggests that for prospective donors who consent after a diagnosis of life-limiting illness, brain donation can provide empowerment or serve as a legacy. For loved ones, supporting an individual to donate or giving consent on behalf of a donor can provide a source of comfort or meaning. Donors and their loved ones sometimes report poor experiences or concerns about the process. A patient-centered accessible approach requires us to minimize obstacles and maximize the benefits of participating in a brain donation program.

Common barriers or disincentives to brain donation include concerns around disfigurement, causing family distress or discord, religious objections, and delay to the funeral. In addition to this, “Brain Exceptionalism” or the notion that the brain holds special significance beyond that of other organs has been cited as a major obstacle for increasing the acceptability of brain donation for some individuals and for some communities. These obstacles often relate to specific contexts or disease paradigms. Consequently, a highly individualized approach to consent is needed.

While these obstacles are well characterized, there is a deficit of discussion as to how biobankers contribute to them or could better support prospective donors to overcome them. For example, the literature is divided as to the existence of brain exceptionalism,^1,2 yet the assumption that discussing brain donation in early-stage disease is likely to cause distress can be a psychosocial obstacle to a person being offered such an opportunity.

Delaying such a discussion until after the person is in the palliative phase can mean the person is no longer able to provide informed consent. This can pose an ethical challenge for biobankers and potentially lead to disappointment if family expectations are not met. Undeniably, clinical intuition and empathy must always guide the appropriateness of a donation conversation, however, the choice to sensitively normalize brain donation as part of early-stage care may serve to combat this obstacle.

Likewise, inaccurate perceptions of disfigurement or delay to the funeral should not be viewed as enduring obstacles, but rather an opportunity for engagement and education. This is particularly pertinent for assumed religious objections—one of the most cited obstacles for consumers. Very few faiths have a documented opposition to organ donation, postmortem, or from living donors. Suggesting or offering conversations that engage religious leaders or other community representatives who are trusted by potential donors can sometimes overcome these perceived obstacles.

The timing and nature of conversations regarding brain donation require a highly individualized approach, potentially aligned with a person's search for meaning or purpose. Some search for a meaning in the immediate aftermath of a diagnosis or loss, and others need time to process. Postdonation perspectives of loved ones are also informative. In as yet published research, we asked the loved ones of people with glioblastoma who had donated their brain: “what was the hardest part?” Responses suggested that the brain donation was not perceived as “hard,” rather it was experienced as a source of hope—affording the potential to provide answers or lead to a cure.

A challenge remains for the brain banking community to acknowledge the vast differences between paradigms from the perspective of the donor and his or her loved ones. To compare brain donation in the context of glioblastoma to a suicide, to a pediatric disease, or to a neurodegenerative condition is to remove the complexity of the human experience. An individualized and personalized approach does take time and may prove to be one of the largest barriers for donors and their loved ones—one that we as a community must address to achieve our common goal.

Address correspondence to:

Cassandra Griffin and Christine Paul

Level 3 West

Hunter Medical Research Institute

New Lambton Heights, NSW 2305

Australia

E-mail: cassandra.griffin@newcastle.edu.au;

christine.paul@newcastle.edu.au

Brain Banking in India—What Is Different?

Relative to its vast population, India's brain banking landscape is limited. Recent funding from the Indian Council of Medical Research (ICMR), however, has supported the expansion of an existing single brain bank operating since 1995 into a network of three nodes, collectively named the Brain Bank Network India initiative. The network hosts a centralized harmonized database and sample collection protocols to enable resource sharing and to serve neuroscience researchers within the country. The ICMR also publishes and enforces ethical guidelines for biomedical research, with the most recent guidelines including a section on biobanking including informed consent, biospecimen and data storage, ethical issues related to donors, research, forensic departments, governance, and measures to safeguard participants.¹

However, a challenge remains in sharing brain tissue internationally. At present, transfer of biological material, other than that required for diagnostic/patient care, is restricted by The Ministry of Health & Family Welfare, Government of India. Any research projects requiring exchange of biological material must obtain prior clearance from the HMSC (Health Ministry Screening Committee). Although revised guidelines have been issued governing the transfer of biological material from India, these still need further refinement.²

The alarming decline in autopsy rates seen globally is also seen in India, affecting availability of human tissue specimens for research. The motivation to order an autopsy usually comes from a clinician. Common reasons cited by clinicians for not requesting an autopsy include an increasingly complex consent process, an assumption that bereaved families are hostile to the idea of autopsy, and advances in premortem diagnostic techniques. These include techniques such as imaging, genetic testing, and serological tests, which can contribute to clinicians assuming that the “cause of death is already known”. Declining autopsy rates are also compounded by lack of time, resources, and clinical or academic incentives.

Other challenges for autopsies include patient and public perceptions, and legal aspects.³ The rise of “virtual autopsies” (postmortem imaging) and needle autopsies and an increasing reluctance by clinicians to request invasive autopsies for fear of litigation have further contributed to reduced number of autopsies being conducted. There is also little incentive for trained pathologists to perform autopsies, which are regarded by some as unpleasant, expensive, and time consuming, and secondary to diagnostic responsibilities.

In India, cultural and religious beliefs and sentiments are often cited reasons for next of kin to decline an autopsy. Diverse religions with differing rituals, beliefs, and norms have great influence on postmortem practices. For instance, certain religions have objections to autopsy (e.g., Islam) as it violates the sanctity of the human body.⁴ Hindus have very elaborate funeral rites, involving cremation and subsequent rituals to guide the departed soul, and believe all organs must be returned to the body.⁵ Most religions believe that a funeral must not be delayed beyond 24 hours, preferably within the same day, and this plays a crucial role in family consenting processes. There are significant cross-cultural variations with Hindus, adhering to cremation traditions, in contrast with Christians, who often opt for burial. The logistical issues, while balancing traditional rituals in contemporary contexts, place additional emotional strain on family members.

Ethical concerns may be compounded by the local context in India. A sizeable population of India lives in poverty and the rate of illiteracy is also high. These social factors may impact the informed consent process as disadvantaged people are at greater risk of being coerced into signing informed consent. In addition to cultural barriers, there are also social taboos and misperceptions, such as the way death is perceived, fears of mutilation, and how the body will be treated. These lead to an overall general reluctance among clinicians to convince bereaved families to donate family members' brains, as it may undermine religious, cultural, and social beliefs. A great deal of commitment is required to persuade families to consent to complete autopsies.

Continuing to grow the discipline of brain banking in India has the potential to influence the broader biobanking landscape across the nation. Dispelling existing misconceptions about harvesting tissues at autopsy will promote philanthropic donation of brain tissue after one's death. Understanding the nuances of cultural and religious diversity will further assist health care professionals, policy makers, and communities to develop socially acceptable and culturally sensitive postmortem practices.

Once the philosophy of harvesting tissues and body fluids for research becomes an integral part of the system, further strategies for funding and sustainability can be developed. In concert, changes in policy to declare clinical autopsies as useful investigative tools will further support brain banking, and in turn have futuristic implications in the development of health care practices.

Outlined below is a seven-point roadmap for the future of brain banking vision in India.

1. Educate medical professionals on the benefits of biobanking for future research. Increase awareness among the scientific fraternity, clinicians, and administrators about the brain donation process, and in particular their key role in communicating with relatives about brain and organ donation.

2. Encourage conversion of biological waste into precious resources for research. Long term, this includes the establishment of small or big brain tissue/fluid banks in major medical centers, and further networking to share material/technology/ideas.

3. Increase public awareness about organ donation. Educate the public about the benefits of tissue banking that creates a “gift of hope” to the next generation. Dispel myths of religious/cultural taboos, misuse, and commercialization of tissues.

4. Clarify and resolve legal and ethical issues pertaining to brain banking. Encourage public participation in policy making.

5. Evolve brain donation registration programs to specifically encourage normal brain donors to address this identified gap.

6. Develop networks and share brain tissues with harmonized criteria for diagnosis, banking, and annotation.

7. Develop a system of rapid autopsies with short postmortem delays to aid molecular biological studies (genomics/proteomics) and brain cell culture utilizing postmortem nervous tissue.

Address correspondence to:

Anita Mahadevan

Department of Neuropathology

National Institute of Mental Health & Neurosciences

Bengaluru 560029

India

E-mail: mahadevananita@gmail.com

Meeting the Evolving Needs of Researchers

Human brain tissue banking can be divided into biopsy and autopsy tissue enterprises. The latter are the major source of whole brains for the study of neurological and neuropsychiatric diseases and are the sole consideration of this article. In Australia, there has been a steady decline in brain bank activities, with only three currently recruiting donors, down from seven in 2015. It is not too dramatic to describe Australian brain banking as experiencing an “existential crisis”. This commentary takes an optimistic view of how small changes by brain banks themselves will see them prosper as a key component of the future research landscape.

Human brain tissue has historically been used by researchers for confirmation of clinical diagnoses and for corroboration of findings from model systems. Yet with the ever-increasing development of molecular techniques, scientists are increasingly using human tissue as a direct model for undertaking mechanistic studies.¹ This appears well justified given that many brain diseases are uniquely human and model systems have produced underwhelming results to date.² However, the inherently retrospective nature of the paradigm does require careful consideration of experimental design, and specifically the brain regions chosen for study and the subsequent data interpretation.³

Brain banking represents a niche and small subgroup of tissue biobanking and has a unique supply chain. There are different models of banking but all share three components: clinical data collection, brain retrieval, and storage and dissemination. The value of postmortem tissue is directly correlated to the clinical data available for each donor. The classic model of brain banking is where a bank partners with a clinical referral center. Clinical data are generated prospectively, the clinicians facilitate donor registration, and the bank ultimately supplies a neuropathological report to confirm the clinical diagnosis and improve clinical practice.

Referral clinics are typically associated with high-profile diseases such as Alzheimer's disease (AD) and motor neuron disease, and clinical data may now include advanced imaging such as positive emission tomography (PET) and blood biomarkers through digital ELISAs. Furthermore, new disease-modifying treatments such as lecanemab for AD⁴ mean an additional role for the neuropathological examination in determining the success of these treatments.

A major issue for brain banks is recruiting sufficient controls. Although the classic model can recruit patient spouses, friends, or family, another approach is to specifically recruit community volunteers.⁵ Here medical data are mainly collected through self-reported questionnaires. The classic model is also not optimal for recruiting donors for stigmatized diseases such as alcohol use disorder or other forms of addiction. In some instances, potential donors with these diseases may find their way into the coronial system, where clinical data need to be collected retrospectively, subject to access and coronial and next-of-kin consent.⁵

All models share the need for a mortuary facility to facilitate brain retrieval. For coronial cases, this is usually concomitant with a triple cavity internal autopsy, but for most prospective donors, this means a brain-only autopsy. Worldwide there has been a massive downturn in adult autopsies in both hospitals and in the coronial setting.⁶ This has occurred for a variety of reasons, including improved imaging for a more confident clinical diagnosis and cause of death.

However, there is also tension between medically trained forensic pathologists and legally trained coroners in Australia over whether and when an “expensive” internal autopsy is necessary.⁷ Banks can actively facilitate tissue retrieval using their own staff, but this remains hindered by morgue closures at many metropolitan hospitals with the decline of adult autopsies. An interest in rapid autopsy programs for supplying tissue samples expeditiously to researchers may be able to reverse this trend.⁸

The motivation for rapid autopsies is that postmortem tissue quality can rival that obtained from surgical biopsies. A major development in brain research has been single-cell transcriptomics. This has moved the investigation and understanding of human brain tissue from a cellular to a cellular subtype level with considerable optimism that cell subtype-specific therapeutic targets will soon be revealed.⁹ Furthermore, there is now spatial transcriptomics¹⁰ that integrates microscopic imaging and transcriptomics together in the same sample, allowing the response of cell subtypes to adjacent pathology to be directly observed, as has already been shown in AD.¹¹ At present, most brain banks hemisect brains where one half is fixed, and the other half is frozen.

Spatial transcriptomics requires optimal RNA quality, and this is relatively high in frozen versus fixed tissue. However, cytoarchitecture is poor in frozen tissue compared with formalin-fixed paraffin-embedded (FFPE) sections. Recent investigations from the Allen Brain Institute suggest that this issue with frozen tissue can be largely overcome,¹² meaning that a major motivation for fixing brain tissue is removed, with downstream impacts on the physical footprint, air exchange systems, and carrying capacity of banks moving forward.

The future of brain banking is facilitating this exciting new science where molecular examination of tissue is complementary to the latest clinical developments. However, to meet funder and societal expectations, it is imperative for brain bankers to “add value” for prospective funders by partnering with other brain banks, other biobanks, and both brain and peripheral disease researchers to look for synergies that make a stronger case for supporting brain banking. Even with enabling funding, banks must rely on in-kind support along their entire supply chain, so it is imperative to consider, including “outside-the-box” ideas, what banks might be able to offer potential donors, their families, clinicians, hospitals, and public health departments to engender their support.

Brain bankers, by definition, have had a brain-centric view of disease, but there are increasing examples of systemic aspects of so-called brain diseases including the microbiome–gut–liver–brain axis.¹³ Brain bankers could collaborate with other tissue banks or use their brain-centric expertise to add value to samples stored by other banks for other diseases. Importantly brain banks can move beyond just brain tissue to encompass, either physically or virtually, other biological samples whose analysis can serve the patient while they are alive and make their gift of tissue more precious after death. The future of brain banking is, therefore, an integrated biolibrary that seeks to serve the needs of as wide a community as possible.¹⁴

Address correspondence to:

Greg Sutherland

Director, New South Wales Brain Tissue Resource Centre

Charles Perkins Centre

The University of Sydney

Sydney

NSW 2006

Australia

E-mail: g.sutherland@sydney.edu.au