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15 We know which regions of the country the centers are in. We
16 do not know what the individual centers are. They are
17 reported to us under code. This was to remove any concern
18 about Big Brother, Sister or whatever looking over the data
19 and pointing fingers.
21 This is the mid-Atlantic and southeast sections of
22 the country -- eastern section of the country. This is the
23 central section. Presumably, these are in mid-America where
24 the blood supply has traditionally been more stable and less
25 subject to fluctuation, whereas this is in the northeast,
31 1 mid-Atlantic and southeast where there is more fluctuation.
2 I also did this in part because I received a
3 report from the America's Blood Centers that a number of
4 their centers had gone out with appeals in the month of May,
5 toward the end of May and early June. This was earlier than
6 they usually did in the past. It wasn't clear whether this
7 was increased utilization for which we now have no data or
8 whether it was decreased collections. We are not able to
9 detect decreased collections. On the other hand, ours is
10 macro data and individual centers are dealing with their own
11 individual micro information.
12 I think I can stop here. If there any questions,
13 I would be glad to answer them.
14 DR. HOLLINGER: Any questions of Dr. McCurdy?
15 Yes, Dr. Simon?
16 DR. SIMON: I think this information is extremely
17 useful, and I am pleased that the effort is being made to
18 collect it and take a look at it. I know that a lot of the
19 focus is on the fallout in terms of donors from the
20 exclusion from people who have been in the United Kingdom
21 for six months, from 1980 to 1996.
22 I think one of the issues that we are dealing with
23 in both plasma and the blood industry there is that the
24 publicity caused many people to self-defer and not show up
25 so that we can't get accurate data on just how many people
32 1 we are losing because that question was introduced. So, I
2 think the kind of data that Dr. McCurdy is giving us is the
3 kind of data on which we will have to rely, that is, what is
4 the final impact on the blood supply.
5 I would also point out that we have tended not to
6 monitor the supply of source plasma. At our last liaison
7 meeting we discussed this with the FDA but there is now data
8 showing a significant fall-off in source plasma donations,
9 possibly in the range of, you know, 10-20 percent over the
10 last couple of years, which has not yet impacted final
11 product but could. So, I think there are a number of supply
12 issues that may be of importance to this committee and the
13 agency in the upcoming months.
14 DR. MCCURDY: It is hard for me to speak off the
15 cuff on this, but I think that the Institute would be quite
16 willing to listen to proposals that might have a similar
17 type of approach to the plasma industry. I don't know
18 whether there is anything collected in that which is
19 universal but we would at least be willing to talk.
20 DR. SIMON: The main universal is that all new
21 plasma donors are checked through the National Donor
22 Deferral Registry. So, ABRA does have a running total of
23 those checks and of the new plasma donors who have shown up
24 at centers. There has been a bit of a problem getting other
25 sources of data because they are proprietary in nature and
33 1 these centers do compete with each other in similar
2 communities, but I think it is certainly something we need
3 to pay more attention to.
4 DR. MCCURDY: In this, we tried to avoid some of
5 the proprietary issues and so forth by having it go through
6 a so-called neutral party and having us know by code and
7 sections of the country but not by individual center what is
8 going on.
9 DR. HOLLINGER: Dr. Epstein?
10 DR. EPSTEIN: Paul, looking at the last graph, the
11 drop in mid-Atlantic and southeast looks precipitous and
12 large. I just wondered if you could comment on how accurate
13 the data are on that graph and then, secondly, a response to
14 Toby Simon, the Canadians have tried to look at the question
15 of measuring the impact of the U.K. related exposure
16 deferral by doing surveys of donors, including non-returned
17 donors. If, in fact, most centers in the U.S. which have
18 implemented U.K. deferral have only done so in late March
19 and April, it may very well be the case that what we are
20 seeing in May is correlated, but I wonder if there has been
21 any thought in the blood community about doing a survey
22 similar to what the Canadians did to actually find out if
23 that is so. Of course, if the dip goes away we perhaps
24 don't care but if it doesn't go away it might help to know
25 why it is happening.
34 1 DR. MCCURDY: The sample for May which showed that
2 is a sample that had six centers from the east area,
3 northeast, mid-Atlantic and southeast, and four centers from
4 the midwest. There were no centers from the west that have
5 come in with reports yet. And, it is only ten. Ten are
6 extrapolated for the whole 26 sample. I think the closer
7 you get to the 26 the more comfortable I am with that
8 extrapolation. So, I think we need more data and we will
9 certainly share that within the PHS and we will probably
10 ultimately, when we get enough to make it meaningful, try to
11 arrange to share it much more widely.
12 DR. HOLLINGER: Paul, I like your metaphor but I
13 don't think this committee ever wants to look at things with
14 a jaundiced eye --
16 -- but, you know, one of the issues with the
17 apheresis donors -- I think Ron Gilcher commented that he
18 was concerned about how that might make an impact. I know
19 you looked at whole blood and a few other things, but what
20 has happened with the apheresis donors, or have you talked
21 to him? I am particularly interested in that because he
22 said a lot of these people are people who have traveled a
23 lot, extensively, and have been gone.
24 DR. MCCURDY: I have not talked with Ron
25 specifically on this issue. About a week ago we made a
35 1 presentation in front of the TSE advisory committee, and
2 that was focused primarily on what we could learn about the
3 U.K. deferrals and timing.
4 Unfortunately, most of the centers came on fairly
5 late, the largest number, and the others came on
6 intermittently throughout which made analysis a real
7 challenge. We could not detect anything that appeared to
8 happen before and after centers that provided that kind of
9 data came online with U.K. deferral. In that, we looked at
10 the apheresis situation. We are collecting information on
11 platelets and apheresis platelets, and we were unable to
12 detect any real change in the availability of apheresis
13 products in that period of time. But analysis is very
14 difficult and this is macro data. We heard some anecdotes
15 at the TSE advisory committee that there were problems in
16 collections and they did, at least in some instances, seem
17 to be related to U.K. deferral.
18 DR. HOLLINGER: Yes, Toby?
19 DR. SIMON: Just as an anecdotal addition, from
20 our company with 64 centers, the thread that is most
21 consistent is proximity to Air Force installations and a
22 little bit of some of the other services, but it is those
23 centers that draw from that population, either active or
24 retired, that are located geographically in such a way where
25 we have seen the biggest impact. That has been the only
36 1 consistent finding. There has been a little bit also in the
2 plasma industry to correlate with Dr. Gilcher's observation
3 that donors in specialty centers that tend to be higher
4 socioeconomic individuals and travel more, there is a slight
5 tendency to pick up a little more there, but the Air Force
6 one has been the most consistent marker.
7 DR. HOLLINGER: Thank you. Thank you, Paul. I
8 look forward to the next report. The final report is the
9 summary of Transmissible Spongiform Encephalopathies
10 Advisory Committee meeting, which was held June 1st and 2nd
11 of this year, and Dr. Asher will give us an overview and
12 comments about that meeting. Dr. Asher?
13 Summary of Transmissible Spongiform Encephalopathies
14 Advisory Committee Meeting
15 DR. ASHER: Thank you. Good morning.
17 The TSE Advisory Committee met on June 1st and 2nd
18 and addressed two issues. First, the issue of potential
19 possible deferral of blood donors with a history of travel
20 or residence in BSE countries other than the United Kingdom,
21 as well as a look back, obviously, concerning the U.K.
22 Second, the possible effects of leukoreduction on reducing
23 the risk of transmitting CJD by blood.
24 As you may recall, although the risk of
25 transmitting CJD via blood and blood products is entirely
37 1 theoretical, the FDA has taken a very conservative position
2 on the issue as recently as November of 1996 recommending
3 withdrawal not only of blood and components but also of
4 plasma derivatives where a donor was belatedly recognized as
5 having CJD or being at increased risk of CJD.
7 However, by the end of 1997 it was clear that
8 there was no demonstrated risk, detectable by
9 epidemiological studies, of CJD in implicated plasma
10 derivatives in transmitting disease. The withdrawals were
11 recognized as not substantially reducing the theoretical
12 risk, at least for recipients receiving multiple exposures
13 when at least 25 percent of large plasma pools used to
14 produce derivatives were likely to contain a contribution
15 from at least one donor who would ultimately get sporadic
16 CJD. There was no screening question that could defer such
17 a donor and no laboratory test available to detect the risk.
18 Withdrawals had failed to retrieve most CJD implicated
19 products anyhow, and CJD withdrawals were contributing
20 significantly to shortages of some plasma derivatives. So,
21 in January of 1998 the PHS Advisory Committee on Blood
22 Safety and Availability recommended that the FDA could relax
23 policy sufficient to relieve those shortages without
24 seriously endangering public health.
38 1 In August of 1998 the Surgeon General, Dr. David
2 Satcher, announced the new policy which was then elaborated
3 in guidance issued by the FDA in September of 1998. The
4 agency recommended continued deferral of donors with CJD or
5 increased risk of CJD and continued quarantine and retrieval
6 of blood and components, but no longer recommended
7 withdrawal of plasma derivatives prepared from pools to
8 which those donors with classical CJD or increased risk had
9 contributed. However, withdrawal of plasma derivatives and
10 quarantine of intermediates prepared from pools to which any
11 donor who developed new variant CJD -- CJD attributable to
12 infection with bovine a spongiform encephalopathy agent --
13 those derivatives would still be withdrawn.
15 The reasons for increased concern about donors
16 during the incubation period of CJD are as follows: First,
17 less is known about the pathogenesis of new variant CJD than
18 sporadic CJD.
19 Second, new variant CJD is an emerging infection
20 not yet recognized in the United States and lymphoid tissues
21 of patients with CJD, and even at the end of the incubation
22 period of new variant CJD, contain detectable protease
23 resistant prion protein while those in patients with
24 sporadic CJD do not, which implies that the blood which
25 contains lymphoid cells might be more infectious in patients
39 1 with new variant CJD than it is in sporadic CJD.
2 Finally, authorities in the United Kingdom decided
3 not to source plasma for preparing derivatives from their
4 own U.K. donors which implied a certain lack of confidence
5 in the safety of the plasma. The FDA then felt compelled to
6 consider the issue of donors who had been potentially
7 exposed to the BSE agent while traveling or residing abroad.
9 Following consideration by the TSE Advisory
10 Committee in December of 1998 and June of 1999, the agency
11 recommended deferral of donors who had resided in the United
12 Kingdom for six months or more cumulative between January
13 1st, 1990 and end of December, 1996, and deferral of donors
14 who had received injections of bovine insulin from the
15 United Kingdom, but did not recommend withdrawal of plasma
16 derivatives for U.K. residents at any period or for exposure
17 to injectable bovine products.
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|Department of health and human services||U. S. Department of health & human services|
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