Blood Safety Summary - August 1997
Advisory Committee on Blood Safety and Availability
Summary of Meeting
Second Meeting August 11-12, 1997
The Chairman called the meeting to order at 9:00 AM. Members present were Dr. Caplan, Dr. Albrecht, Mr. Allen, Dr. AuBouchon, Dr. Busch, Dr. Gilcher, Dr. Gomperts, Dr. Guerra, Dr. Haas, Dr. Hoots, Ms Jones, Dr. Kuhn, Ms. OConnor, Dr. Penner, and Mr. Walsh. Ex Officio representatives present were Dr. Goosby, Dr. McCurdy, Dr. Chamberland, Dr. Snyder, and Captain Rutherford; Dr. Wycoff attended in place of Ms. Pendergast.
Dr. Eric Goosby, on behalf of Dr. John Eisenberg, the Principal Deputy Assistant Secretary of Health, welcomed the participants and introduced the newly appointed Executive Secretary of the Committee, Dr. Stephen Nightingale.
Mr. Jim McPherson, representing Americas Blood Centers, was the first person to address the Committee. Mr. "... donor lookback will not identify" the majority of patients who have [been] infected ...; nevertheless, it is difficult to argue that blood centers in possession of information about a recently acquired infectious state of a donor should not perform lookback for HCV as they already do for HIV and HTLV." Mr. McPherson requested that a limit be placed on the time of any prospective lookback program, that the government provide funding for any prospective lookback program, and that provider and patient educational initiatives be considered in lieu of a retrospective lookback program.
Ms. Fay Lamb, representing the Cooleys Anemia Foundation, requested the Committee support a lookback system which would notify~" patients "... that there is a reasonable probability that they have received tainted blood" and that adequate counseling be provided to those so notified.
Dr. Paul Mied of FDA then summarized FDA policies regarding product retrieval and recipient notification in transfusion lookback programs for HIV, HBV, HCV, and HTLV-I. Current policy, established in June 1996, is that product quarantine and recipient notification are recommended for HIV; for the others, only product quarantine is recommended. Dr. Mied noted that in June 1993, after introduction of the second-generation antibody and the REBA-2 confirmatory tests for HCV, the FDA Blood Products Advisory Committee (BPAC) had recommended consignee notification for purposes of recipient notification of possible HCV exposure by a vote of 5 to 4, but that BPAC had expressed reservations about the benefit of this activity.
Dr. Harold Margolis of CDC reviewed the PHS Plan for the Prevention and Control of Hepatitis C. Dr. Margolis emphasized the need for education of both providers and the public. He mentioned the March 1997 NIH Consensus Conference on HCV the planned November 1997 CDC teleconference on this subject, and the contributions of non-governmental organizations to the educational effort. Dr. Margolis also expressed concern over the high prevalence of HCV infection in prison populations and the difficulties in providing HCV testing to medically indigent populations. In response to questions, Dr. Margolis noted that about 3.9 million Americans (about 2%) are thought to be infected with HCV, about 8,000 to 12,000 deaths each year in the United States are attributable to HCV, that the incidence of HCV has decreased by about 90% since 1990.
After a recess, Dr. James AuBouchon presented a cost-effectiveness analysis of HCV Iookback. Using American Red Cross data, he estimated that between 1990 and 1995 88 % of donors were repeat donors, that there were approximately 91,000 donors who were identified as HCV-infected at a repeat donation, and that about 5 blood components would have been derived from each donor between 1985 and the time the donor was found to be HCV-infected. He estimated that approximately 60 % of the 450,000 potential recipients of these potentially infectious components would be dead, that only 33 % of the survivors would be traceable, that 40 % of those traceable would not be infected either because the HCV test of the donor was a false positive or because the recipient was either never infected or spontaneously recovered, that 70 % of those found to be truly positive would be candidates for therapy, and that 15 % of these would benefit from therapy. Dr. AuBouchon estimated it would cost $137 to identify~" each donor or $27 per component, and that the age of the average recipient would be 60.
Dr. AuBouchon found that, in his model, the cost-effectiveness of lookback was most sensitive to the benefit he assigned to interferon therapy, to how recent the transfusion was, and to the age of the patient. He felt that the average cost-effectiveness of lookback in his model ($88,000 per year of life extended) was comparable to other therapies; however, he concluded that only I per hundred in the original pool of 450,000 recipients would benefit from a Iookback.
Ms. Lisa Ungerer then addressed legal issues surrounding lookback, focusing on "avoidable lawsuits". She recommended a standard and easily understandable notification format, and cautioned that ad hoc approaches to notification might increase exposure to litigation.
Dr. Ronald Gilcher then discussed differences in Iookbacks for the periods prel99O, 1990-present, and present onward to the future. He acknowledged that his analysis was very similar to that previously presented by Drs. Margolis and AuBouchon.
Dr. Harold Kaplan followed with a discussion of the impact of lookback on hospital transfusion services. He estimated that for a hospital with a computerized transfusion record system, about 90 minutes work time would be required per notification attempt. At his 1000 bed hospital he estimated about 1500 notifications, which would consume the efforts of 1.3 full-time-equivalent workers for one year. Dr. Kaplan noted the impact of such a lookback would be ameliorated if it could be spread over one year.
After a lunch break, Dr. Stuart Gordon and Dr. Leonard Seeff described clinical aspects of hepatitis C infection in their practices. Dr. Gordon studied 627 consecutive patients with HCV infection. He found more severe disease in older patients, and in patients who had acquired HCV by transfusion rather than by intravenous drug use. In Dr. Seeff's own cohort of 568 cases, 53% of patients have persistently elevated liver enzymes at 15 to 18 years after infection; 10 % no longer have antibody, and 28% no longer have PCR-detectable antigen at this point. In contrast, 13 % have symptomatic liver disease, and I % have developed hepatoma.
Dr. Angela Robinson then described the British experience with HCV Iookback. She noted the differences between the British and American health care systems, and the fact that Britain began HCV screening with the second generation HCV test with REBA confirmation. The decision to perform a lookback was made in 1994 on the basis of "duty of care". In Britain, with a population of about 50,000,000, about 3,000 HCV-infected donors and about 12,000 blood components from these donors were identified. About 6,000 recipients were identified, of which 4,000 had died; 75 % of the survivors were located. At present 581 of these are HCV positive, 369 HCV negative, 75 indeterminate. Twenty of the 581 HCV positive patients have symptomatic liver disease.
Dr. Peter Gill then described the Canadian experience with HCV Iookback. Canada also initiated a HCV lookback program in 1994. A provider and public education program was implemented, including brochures and toll-free hotlines for providers and public. Canada introduced the first generation HCV test at the same time (March 1990) as the United States, and the second generation test in 1991. The yield of lookback was very similar to the British yield.
The day concluded with a general discussion of the issue of HCV Iookback. At the conclusion of this discussion, the minutes of the previous meeting were approved unanimously. The meeting recessed at 5:32 PM.
Dr. Caplan called the Committee to order at 8:00 AM on August 12. Dr. Michael Busch discussed the risks of transfusion, and how they had decreased in recent years. At present, he stated that potential failure to interdict infection can be due to preseroconversion windows, viral variants, silent carriers (non-seroconverters), and technical error. For HCV, the pre-seroconversion window is roughly 80 days from exposure to seroconversion, and viremia occurs during this period. HCV viral variants are very rare. Silent carriers occur in about 1:10,000 HCV infections. Dr. Busch estimated test error at a rate of 0.067%; however, this error must occur in processing a contaminated specimen for it to be clinically significant, and the combined probability of these events is small. The cumulative risk at present fro HCV transmission by any of these mechanisms is now about 1 in 5000, and for any of HIV, HBV, HCV, or HTLV-I it is about 4 in 10,000.
Mr. Edward Maibach of Porter Novelli then gave a presentation about dealing with and communicating risk. He enumerated several cognitive strategies humans use to process concepts of risk and uncertainty, for example the tendency to overestimate the frequency of rare events, and he made several suggestions for communicating information about risk, for example use of language appropriate for the target audience.
The remainder of the meeting was taken up with formulation of specific recommendations. The discussion began with a draft proposal of Dr. Hoots; numerous modifications were proposed. After a luncheon recess, Dr. Busch suggested a modification of Dr. Hoots proposal. After further discussion, the Busch modification of the Hoots proposal was approved by a vote of 13 to 0, with Dr. Penner abstaining and Dr. Caplan, the Chair, not voting. The approval was with the understanding that the proposal would be edited for grammar and clarity, with modifications submitted to the Committee members for their approval. The final text of this Resolution is amended to these minutes.
Following the vote, Dr. Penner stated that he agreed with what the Committee had done so far, but felt it had not gone enough because it did not support lookback for first generation-positive donations. Dr. Penner stated he hoped the Committee would return to this issue at a future time. Dr. Caplan stated that he would consider Dr. Penners request, and that he leaned in the direction that Dr. Penner was articulating.
The meeting was adjourned at 3:00 PM.
Stephen D. Nightingale, MD