Process That Zaps Risk From Donated Family Blood Now Standard

Ashley Quaco dozes in her mother’s arms, unaware of the disease that might have killed her and the technological feats that kept her alive.

Ashley was born March 11 at Palomar Medical Center in Escondido with an extremely low level of platelets, the components that form the necessary scaffolding for blood to clot. She needed an infusion of donated platelets within a few hours to prevent runaway internal bleeding.

But a transfusion from the quickest and likeliest source, her mother, Tammylee, might have exposed the baby to risk of a fatal immunological condition called graft-versus-host disease.

Indeed, such a transfusion reaction killed another San Diego baby with this platelet disorder in 1985 at Children’s Hospital, said Dr. Howard Robin, who oversees transfusions at neighboring Sharp Memorial Hospital, which at the time provided blood collection services for Children’s.

The solution this time was irradiation, zapping the mother’s donated platelets for a few minutes in a $50,000 machine about the size of a small refrigerator. This disarmed any white blood cells that otherwise might have fatally attacked Ashley’s tissues.

Over the last year, irradiation has gone from being a procedure used only when a patient has a faulty immune system to being a standard procedure in San Diego for transfusions of blood products from one family member to another.

The technique may become increasingly important in the next several months as doctors begin implementing the state Paul Gann Blood Safety Act--a measure that requires them to advise surgical patients of alternatives to blood transfusions from unknown donors to a blood bank.

Gann, co-author of Proposition 13, died in September of complications from AIDS, which he acquired from a 1982 blood transfusion during heart surgery.

Under the Gann Act, patients must be told that they can donate their own blood in advance of surgery--the only 100% safe transfusion--or get relatives and friends to donate blood specifically for them.

“As that becomes something that is normal for hospitals, donor-directed and autologous donations will increase,” predicted Bill Ornelas, supervisor of the year-old blood bank at Children’s Hospital.

Dr. Rebecca Fleck, assistant medical director of the San Diego Blood Bank, disagrees.

“It’s certainly leveled off, and it actually is starting to go down a little bit,” Fleck said. “The Gann Act might increase it a little temporarily, but I don’t think it’s going to increase it in a major way.”

Children’s Hospital is seeing a steady increase in the number of parents who want their children transfused with blood only from themselves or relatives, Ornelas said.

Of about 300 pints of blood collected there every month, half have a designated recipient, Ornelas said.

Blood bank officials say close questioning of blood donors, as well as screening donated blood for AIDS and hepatitis, make the nation’s blood supply safer than it ever has been. Still, there is some risk.

“The blood supply can never be declared 100% safe. It’s safer than it ever has been, but there’s no such thing as 100% in biology,” said Dr. Jerry Kolins, medical director of the Community Blood Bank of North County.

A new test for a previously undetectable type of hepatitis is not yet available, so people could acquire it from donated blood. Other chronic viral infections such as cytomegalovirus can be spread by blood. There has also been some concern that new varieties of HIV, the AIDS virus, may be undetectable.

It is a desire to cut these possible risks that leads parents to keep donations in the family, Fleck said.

“All the risks that we have in the blood supply have always been there, with the exception of AIDS. But AIDS has focused people’s attention on it,” Fleck said. “Parents are highly motivated individuals who care desperately about their children, and so that’s why they as directed donors might continue to grow.”

But donations among close relatives are most likely to cause graft-versus-host disease in transfusion recipients.

Graft-versus-host disease is a largely fatal immunological condition that occurs much like the rejection phenomenon in organ transplants. In organ rejection, the recipient’s immune system sees the transplanted tissue as foreign and tries to destroy it with infection-fighting white blood cells, lymphocytes.

In graft-versus-host disease, however, it is the donor’s lymphocytes that mount an attack on the recipient’s tissues.

The surface of lymphocytes are dotted with genetically determined chemical sites, called antigens, that distinguish between their body’s cells and foreign cells. When lymphocytes see an antigen they don’t recognize, they construct antibodies to destroy the invader.

Unrelated people are unlikely to have lymphocyte-surface antigens that match, but close relatives often do.

Graft-versus-host disease occurs when the donor’s cells have two identical copies of the genetic code for one of these antigenic sites, but the recipient shares only half of that code.

Thus, the recipient’s immune system sees the donor lymphocytes as native rather than foreign tissue, and does not destroy them. But the donor lymphocytes see the half of the recipient’s antigenic code that they don’t share, and treat it as foreign tissue. These invading lymphocytes multiply and disable the recipient’s immune system.

Irradiation prevents this by disabling lymphocytes in the transfusion product. It does not make the blood product radioactive, nor does it affect other cells, doctors say.

About 90% of graft-versus-host disease patients die of resulting infections. Cases are rare, but some doctors believe many have gone unreported.

Until last summer, irradiation of blood products was seen as necessary only if the recipient’s immune system was not working--for instance, in bone marrow transplant recipients or in very young infants.

Then, last July, Israeli physicians reported the condition in two cardiac surgery patients with competent immune systems. They had received transfusions from their children.

As a result of that report in the New England Journal of Medicine and of other reports from Japan, the San Diego Blood Bank and Scripps Clinic that month expanded irradiation of blood products to include all donations from one close relative to another. The blood bank supplies the most of the blood in the county, taking about 10,000 pints in donations every month.

At Scripps, which each month collects about 100 pints of primarily donor-directed blood, irradiation had been common before the expanded policy because many recipients are bone marrow transplant patients, said Dr. Robert M. Nakamura, chairman of the pathology department.

Both the VA Medical Center and Navy Hospital send people who want to give blood to relatives to the San Diego Blood Bank, where it can be irradiated, spokesmen said. Neither sees more than 50 pints per year of such donor-directed blood, they said.

The Community Blood Bank of North County adopted universal irradiation for familial transfusions in late October, just before the American Assn. of Blood Banks made a November recommendation for the practice. The bank processes about 1,200 pints of blood a month.

Consequently, if the Gann Act indeed causes more San Diegans to turn to family members for blood donations, area blood banks will be ready to irradiate those donations.

Although the law took effect Jan. 1, the state Department of Health Services is still drafting a form that doctors will have to give patients under the law. A final document to be issued by the Board of Medical Quality Assurance is expected this summer, said Ron Harkey, a state laboratory regulator who is working on the plan.

Even without the law, Scripps Clinic’s Nakamura believes directed blood donations won’t fade.

“There’s no real scientific evidence at this time that your friend or relative’s blood is any safer than that in the regular community,” Nakamura said. “However, perception is reality, and I’m not so sure you’re going to convince people otherwise.”