Workshop on Maintaining Iron Balance
in Women Blood Donors of Child-Bearing Age
Sponsored by: The National Heart, Lung, and
Blood Institute (NHLBI), American Association of Blood Banks,
Americas Blood Centers, and the American Red
Cross
Lister Hill Auditorium, NIH, Bethesda,
MD June 8, 2001 |
Meeting
Summary |
Staff
Contact/Phone Dr. George Nemo, (301) 435-0075 (nemog@nih.gov) Dr. Liana Harvath, (301)
435-0075 (harvath@nhlbi.nih.gov)
Dr. Barbara Alving, (301) 435-0080 (alvingb@nih.gov)
Purpose/Objective To discuss the medical, economic
and operational feasibility of implementing a program of carbonyl iron
replacement to prevent iron deficiency in women blood donors of child-bearing
age.
Workshop Speakers/Panel Members
Workshop speakers and panel members consisted of physicians with expertise
in hematology, oncology, transfusion medicine, and blood center management, as
well as representatives from the major blood banking organizations and
patient/public advocacy groups. They were: Randy Alexander, Iron Disorders
Institute; Cheryl Aylesworth, M.D., Uniformed Services University of the Health
Sciences; Celso Bianco, M.D., America's Blood Centers; Gary Brittenham, M.D.,
College of Physicians and Surgeons, Columbia University; Linda Chambers, M.D.,
National Headquarters American Red Cross; Richard B. Counts, M.D., Puget Sound
Blood Center; Roberta Crawford, Iron Overload Diseases Association; Ronald O.
Gilcher, M.D., Oklahoma Blood Institute; Victor R. Gordeuk, M.D., Center for
Sickle Cell Disease, Howard University; Paul Holland, M.D., Sacramento Blood
Center; James P. Kushner, M.D., University of Utah Medical Center; Jay
Menitove, M.D., Community Blood Center of Greater Kansas; and Merlyn Sayers,
M.D., Ph.D., Carter Blood Care.
Meeting Agenda
Summary
Data were presented on the scope of the problem of blood donor deferrals
due to low hemoglobin levels. There was agreement that many women blood donors
are borderline in terms of iron stores. Approximately 5% of donors, 95% of whom
are women, are deferred because of hemoglobin levels below 12.5 g/dL.
Phlebotomy-induced iron deficiency is a significant problem resulting in
significant loss of donations, many of which come from the most motivated,
repeat donors. This problem affects special donors, such as O negative donors,
disproportionately. Phlebotomy of a unit of blood produces a loss of 200 to 250
mg of iron in hemoglobin. Because the average amount of storage iron in a woman
of child-bearing age is only about 300 mg, donation of a unit of blood requires
the subsequent mobilization of much or all of this reserve. Further donations
of blood will produce iron deficiency and then anemia. In women who donate
blood repeatedly, iron absorption from a usual diet can not increase
sufficiently to replace iron losses from frequent phlebotomy. One option to
prevent development of iron deficiency would be to lengthen the donation
interval for women to every 6-12 months, for example, or use a standard 56 day
interval only if they receive iron replacement.
In a study supported by the National Heart, Lung, and
Blood Institute, extramural investigators demonstrated the safety and efficacy
of short-term carbonyl iron administration to frequent, committed female blood
donors. The study showed that carbonyl iron supplements are an efficacious
means for increasing blood donation in women of childbearing age. The results
provide a scientific and practical basis for the consideration of short-term
carbonyl iron replacement for menstruating women donors who wish to be donors
as frequently as four times each year. This approach is becoming increasingly
attractive as additional donor deferral criteria are put in place to protect
the safety of the blood supply. Nevertheless, the workshop participants
questioned the practicality of supplementing the diet of regular female donors
under the age of 45 with iron so that they can continue to donate. It is clear
that replacement of the iron that has been lost can be done. But there are many
practical issues that need to be addressed when trying to apply what has been
learned in small research studies to large groups of donors. What will be the
cost of iron replacement per donor? Could a donor recruitment program be as
cost effective with less risk? How is the success or failure of the program to
be measured? There was general agreement that any programs evaluating iron
replacement would need to be performed as research investigations at this time,
since experience in this area has not yet risen to the level of standard
practice.
Information for donors should be tailor-made to
permit good understanding of the risks of iron deficiency and the interventions
that are recommended to prevent it. Many female donors already take iron
supplements and have increased iron in their diets. All participants agreed
that carbonyl iron should be used, whether provided to the donor by the blood
center or recommended to the donor as the type of supplement to buy, in order
to reduce the likelihood of toxicity in case of accidental ingestion by
children in the donor's household. Carbonyl iron is absorbed slowly from the GI
tract and therefore has greatly reduced toxicity if accidentally ingested in
large doses. The most common side effect of daily doses of carbonyl iron (mild
GI discomfort) is similar in frequency to ferrous sulfate/gluconate. Possible
disadvantages of iron replacement programs include limited compliance due to
side effects, the possibility of masking underlying diseases associated with
blood loss, and the risk of giving iron to individuals with undiagnosed
hereditary hemochromatosis.
What harm can be
done? The largest group of deferred donors are menstruating
women who, even with hemochromatosis, are unlikely to have iron overload and
organ damage. Hemochromatosis screening was discussed. One blood center is in
the process of initiating screening for the HFE gene (a genetic determinant of
hemochromatosis). The cost of the test is modest (may be as low as $5.00 under
special circumstances) and only has to be performed once. However, there were
concerns expressed that genetic screening carries with it the potential for
discrimination of those found to have the atypical gene(s) with regard to
employment, or health or life insurance.
Another risk of iron replacement may be delayed
diagnosis of such disorders as GI neoplasms, other neoplasms associated with
blood loss, or peptic ulcer disease. However, these conditions occur rarely in
the group between 18 and 45 years of age. It was recommended that a
supplemental questionnaire be designed that would identify donors at higher
risk of having non-iron deficiency causes of anemia, asking such questions as
"Does anyone in your family have colon cancer?", "Do you take medications for
heartburn or ulcers?", and "Do you have ulcerative colitis or Crohn's disease?"
It is estimated that iron supplementation would
increase the number of units available for transfusion by about a half million
per year. This was considered to be a significant number by the workshop
participants.
The approach of supplementing early in the donation
process in order to prevent iron deficiency, rather than treating
phlebotomy-induced iron deficiency, was better accepted by the participants.
Most thought that, at some point in any protocol of iron replacement, a more
complete evaluation of iron status (e.g., ferritin, transferrin iron
saturation, etc.) should be undertaken to evaluate the effects of replacement
and to eliminate any participants who are asymptomatic.
The patient/public advocate participants were
supportive of broader use of iron studies to evaluate donors, and indicated a
willingness to be involved in subsequent studies and discussions on the matter
of iron supplementation in blood donors.
The point was made that the cost of a donor
recruitment program to replace lost donors due to iron deficiency may be less
than the cost of a research iron replacement program. An iron replacement
program may well require special nurse coordinators. It may also be necessary
to continue special non-standard management of the supplemented donors in order
to keep them involved. At one blood center in which women received iron
replacement during a research study, a significant drop-out of donors occurred
when the study was completed and the participants who had received iron
replacement were moved into the routine program. It was stressed that a
committed staff is needed for an iron replacement program to be successful.
Furthermore, the staff needs to be educated fully about the program.
It was agreed that iron physiology in blood donors is
well understood and that iron replacement works, at least in the controlled
environment of a research program. It is the operational issues that still need
to be resolved and evaluated. It was pointed out that usual methods for donor
hemoglobin screening are both insensitive and nonspecific, so that an accurate
identification of donors with hemoglobin below 12.5 g/dL would require use of
more reliable sample types (e.g. venipuncture instead of fingerstick) and
testing (e.g. automated counter instead of spun microhematocrit) methodologies.
Participants also identified the need for donor input. Donors should be queried
about how they feel about becoming iron deficient from donation. How do they
respond to being deferred for having a hemoglobin value below 12.5 g/dL? Are
they receptive to taking pills in support of voluntary donation? Will they
comply?
Most participants thought that iron replacement
should be offered, preferably in a research study, to special subgroups of
donors such as those with blood types in great need (e.g., O negative) or who
have rare blood types. Most believed that the operational barriers are too
great to offer iron to all blood donors in need of replacement, or to forestall
iron deficiency.
Recommendations:
- Consider implementing a demonstration and education
research program of iron replacement in women blood donors of child-bearing
age.
- The objective of the research program is to
determine the operational feasibility of providing carbonyl iron replacement to
these donors.
- The program should involve several blood
centers.
- Studies of donor attitudes concerning an iron
replacement program should be considered.
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