Female Plasma May Not Be as Harmful as Once Thought
DURHAM, N.C. – As the national blood banking community
considers limiting the use of plasma from female donors because
of a rare but potentially catastrophic lung condition,
researchers from Duke University Medical Center have shown that
this policy change might be premature.
In their analysis of 8,300 heart surgery patients, the
researchers found no association between transfused female
plasma and any adverse outcome. In fact, they found a
significant decrease in complications in patients receiving
only female plasma.
Plasma, which makes up about 55 percent of blood's total
volume, is the liquid portion of blood that is separated from
oxygen-carrying red blood cells after donation. It is pale
yellow in color and is usually given to patients after surgery
to help restore their blood's normal clotting ability.
Transfused plasma from female donors has been implicated as
a cause of a rare condition known as transfusion-related acute
lung injury (TRALI), in which the lungs fill with fluid. The
incidence of TRALI is hard to determine, and it is estimated
that it occurs at a rate of 1 in 1,300 transfusions to 1 in
5,000 transfusions. It is the leading cause of
transfusion-related death in the United States.
"Our data showed no deleterious effect associated with
female plasma transfusion, and even pointed toward the
possibility of a protective effect," said Duke anesthesiologist
Ian Welsby, M.D. Collaborator and co-author Marla Brumit, M.D.,
from the Carolinas Region of the American Red Cross, presented
the results of the Duke study at the annual meeting of the
American Association of Blood Bankers in Anaheim, Calif.
While red blood cells can easily be separated from whole
blood, antibodies from immune cells remain in plasma products,
which is the root of the problem. Pregnant women develop a
specific kind of antibody in response to carrying a baby, which
is genetically half mother and half father. The more children a
woman has, the more of these antibodies are produced. It is
thought that some recipients of transfused plasma from women
react negatively to these antibodies in the plasma.
Because of this apparent risk, the United Kingdom has used
only plasma from male donors since 2004.
"TRALI is important and effective preventative steps should
be taken to prevent it; however, we believe that more
prospective data needs to be evaluated prior to enacting a
policy such as the one in the United Kingdom," Welsby
continued. "By focusing on a single rare event, they may be
missing the forest for the trees. The bottom line is that
female donor plasma may not be as harmful as it has been made
out to be and antibodies from female plasma are only one source
The Duke researchers scoured their extensive database of
patients who underwent cardiac surgery over a ten-year period
beginning in 1993, looking for any possible negative effects in
patients who received female plasma. These patients were chosen
because surgery and the use of the heart-lung machine during a
procedure are both important risk factors for developing
Of the sampled patients, 25.6 percent received plasma
transfusions, of which 44.8 percent came from female
"We found that the volume of plasma a patient received was
associated with higher mortality, which makes sense, since if
you can stop the bleeding sooner, the patient will do better,"
Welsby said. "However, there was no association between female
plasma and death, respiratory complications or even delayed
recovery. These results raise questions concerning the overall
benefit of a broad policy that completely excludes the
transfusion of female plasma."
The researchers were also intrigued by the finding that
female plasma may actually reduce complications after heart
surgery. They are planning future prospective studies to better
understand this phenomenon.
"Theoretically, there are some plausible reasons supporting
the idea that female plasma may help patients," Welsby said.
"Female plasma contains estrogen and other hormones that are
known to promote blood clotting and have anti-inflammatory
Other Duke members of the team were Barbara Philips-Bute,
Mary Lee Campbell, Joseph Mathew, Carmelo Milano and Mark
Stafford-Smith. Theresa Boyd and Rebecca Ramsey from the
American Red Cross were also a part of the analysis.