Human Tissue Transplants : Making Tissue Safer, Donor Eligibility

by Food and Drug Administration (FDA)

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Making Tissue Safer

The FDA has been working to make human tissues safer since it first started regulating the tissue industry in 1993. That year, the agency published an interim regulation that called for certain screening requirements to be met before donated tissues were considered safe for transplant. This regulation, finalized in 1997, also gave the FDA the authority to recall and order the destruction of potentially unsafe human tissue and to inspect tissue banks — organizations that provide a range of services, including donor screening, tissue recovery, and processing, storage, and distribution of tissue.

The explosion in tissue technology did not catch the FDA by surprise. The 1993 interim regulation included wording to indicate that the FDA would strengthen its tissue regulations in the future.

The final 1997 regulation applied only to certain tissues, such as skin, eyes, and bones, tendons and ligaments (musculoskeletal tissues). Screening under the regulation focused on preventing the transmission of HIV, hepatitis B, and hepatitis C.

More recently, the FDA finalized three new rules that give the agency more authority and oversight over a broader range of tissues and the establishments that process them. The rules also expand on the communicable diseases that are checked for, and they strengthen procedural and recordkeeping requirements for facilities that handle tissues. Before finalizing the rules, the agency held public forums and considered comments from a broad range of consumer representatives, health and science professionals, and industry.

"Some of the same approaches that have been used successfully to improve the safety of blood are also being used to make tissue safer," says Goodman. The goal is "to improve protection of the public health without imposing unnecessary restrictions on research, development, or the availability of new or existing products."

The three rules concern registration and listing, donor eligibility, and good tissue practices related to human cells, tissues, and cellular and tissue-based products, known as HCT/Ps. These products include skin, eyes, musculoskeletal tissue, eggs and sperm, veins, blood stem cells, the membrane covering the brain (dura mater), and more. The agency has tailored its regulations to the degree of risk posed by each product.

The FDA's rules do not cover certain bone marrow or whole organs for transplant. These are managed under separate programs in the federal Health Resources and Services Administration (HRSA), part of the Department of Health and Human Services.

Registration and Listing

This rule was finalized for certain HCT/Ps in 2001 and for all HCT/Ps in 2004. It requires all establishments that recover, process, store, label, package, or distribute HCT/Ps, or that screen or test donors, to register with the FDA and list all the products they manufacture. This regulation provides, for the first time, a complete database of tissue banks and other establishments that work with human cells and tissues. Its aim is to increase the efficiency of the FDA's inspection and monitoring and help the agency better communicate with facilities about its policies and guidances.

Donor Eligibility

"A critical component of enhancing the safety of tissues is excluding donors who may pose a higher risk of transmission of infectious diseases," says Goodman. The FDA's donor eligibility rule requires that tissues for transplant come from an eligible donor, based on the results of screening for risk factors and testing for certain diseases. This is an extensive process that involves examining the body, testing for disease-causing agents, interviewing the donor's family or other close contacts, and conducting multiple reviews of a donor's medical records, lab test results, coroner and autopsy reports, and other relevant records.

Finalized in May 2004, the rule takes effect on May 25, 2005. In addition to screening and testing for HIV and hepatitis, as was done under an earlier regulation, the new regulation requires screening for diseases such as syphilis, West Nile virus, severe acute respiratory syndrome (SARS), and the neurological condition Creutzfeldt-Jakob disease (CJD).

No lab tests are currently available to test for West Nile virus, SARS, and CJD. To identify a potential risk for these diseases, a tissue bank representative interviews the family of the deceased donor. Interviewers at Donor Alliance typically have social work or psychology backgrounds, says Mansfield, and they ask about 50 questions to gain extensive information about the donor's medical and lifestyle history that may signal a risk, including sexual practices, injectable drug use, and travel history. Donors who lived in Britain, for example, at the height of the "mad cow" epidemic are excluded from donating because they are considered at risk for the human form of mad cow disease, variant CJD.

To further protect transplant recipients, the donor eligibility rule builds in flexibility for the FDA to require screening for new disease threats as they emerge and reliable tests become available.

Donor tissue cannot be released for use until all screening and testing processes are completed and medical experts review and evaluate the results. An exception may be made in the event of an urgent medical need where no suitable tissue is available and the recipient is likely to become gravely ill or die without the tissue.

Any donor found to have infected tissue or found to be at risk for infection is considered ineligible, and, with rare exceptions, all tissue from that donor is destroyed or used only for research or educational purposes. "We can send tissue that cannot be transplanted out for research if the family has agreed for it to be used for research," says Mansfield.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.