|Dr. Barbara Bryant of the Clinical Center’s department of transfusion medicine is conducting
the IRON study.
Before blood donation can even begin, donors are screened to make the process safe for them and for potential recipients. Donor screening
includes a medical history interview, vital signs and a fingerstick blood test to measure hemoglobin (Hb). Hb reveals if the donor has anemia or is likely to become anemic after donation. Such donors are deferred—temporarily not permitted to donate blood. The most common cause of anemia in the blood donor population is iron deficiency.
“Getting deferred is hard to take,” says Bryant. It can also be hard for the blood bank, since “it’s so frustrating to have to turn away donors, especially repeat, committed
donors. It’s even harder to have to go out and recruit new donors—all kinds of studies show that.”
In the DTM, over 14 percent of donors presenting for whole-blood donation and nearly 8 percent of donors for platelet donation are deferred at least once a year due to low Hb values. At NIH and beyond, although the problem has been reported for decades, there’s been no resolution; no large long-term studies have yet been published.
“It’s been debated quite a bit and we acknowledge
this,” says Bryant, who should know, having
worked 17 years as a blood-banking medical
technologist before entering med school at the University of Texas, Galveston. “I appreciate
all these people doing [blood-bank] jobs,” she says. “I’ve done them.” She is now a clinical
Although she trained in both anatomical and clinical pathology, she chose the latter, which means she sees patients at bedside. “In my residency,
I was the one with the stethoscope. I have a huge interest in red cells and I’m very clinically oriented, which is why I came here for a fellowship. Before I know it I’ve got 700 donors that I’m following.”
Here’s the challenge. Iron is part of the protein
called hemoglobin, the pigment that makes blood red and carries oxygen from the lungs to the tissues. People with anemia don’t have enough iron to make the normal number of red blood cells so they tire easily, even after mild exercise. Women have smaller iron stores and premenopausal women have higher iron needs since their bodies must compensate for monthly
“We see [low iron] in men too,” Bryant says, “but in women it’s much more common.” Normally,
“the body’s really smart”—it releases iron from the body stores to make more red cells and works harder at absorbing available iron from the diet. But if the body’s iron stores have been depleted, dietary iron alone may not be enough.
So let’s say first-time donors, responding to a campus blood drive, flunk their fingerstick Hb tests. Bryant would ask pertinent questions. Do they have exceptionally heavy menstrual
periods? They may need to see an OB/GYN. Are they vegetarian? Lack of red meat in the diet can contribute to iron depletion. Have they been told they have a low Hb in the past? Many donors have not followed up on past recommendations
to take iron supplements.
Occasionally, people who are iron-depleted or iron-deficient may complain of fatigue or of craving and consuming unusual things like large volumes of crushed ice. They may even complain
of restless leg syndrome. Many donors report that they feel better and less fatigued on iron replacement.
Donors who currently have low fingerstick Hb values, as well as returning donors who have had low Hb levels in the past, are offered the opportunity to be in the IRON protocol. A complete
blood count and iron studies are drawn; then the donor receives a 60-day supply of iron tablets to raise his or her Hb. On follow-up visits
the donors receive repeat laboratory testing
and additional iron as needed. One donor was delighted to find that, in addition to donor cookies, she can now receive donor iron at the time of each donation.
It’s not Bryant’s purpose to be a primary-care physician, but seeing at least 10 donors a day means she does a lot of teaching and follow-up phone counseling.
“I went to CVS and wrote down every [iron] formulation they had and tabulated the cost per pill”—helpful stuff, in case donors tell her they “take the red pill in the tall skinny bottle.” That helps her identify the brand and informs her choice if she needs to switch the formulation to one with fewer side effects or a higher iron content.
“Donors are good people,” she says. “For a lot of them, this is their public service. So we want to know, should we replace the 240 mg of iron lost in a unit of blood? This study may prove it’s a good thing. If it allows donors to donate, it’s excellent.”
To learn more about why it is important to donate, visit www.cc.nih.gov/dtm.