Dr. Naynesh R. Kamani/Eddie Benavides

Sustaining life
with bone marrow

by Joanne Shaw

With just a few ounces of the right kind of blood and the expertise of a Health Science Center physician, a young boy is successfully battling leukemia.

Eddie Benavides, 8, and Naynesh R. Kamani, MD, associate professor of pediatrics, share a piece of Health Science Center history--the first stem cell transplant using blood from a placenta performed at the Howard A. Britton, MD, Children's Cancer and Blood Disorders Center at Santa Rosa Children's Hospital.

Traditionally, life-sustaining stem cells have been harvested from bone marrow. Dr. Kamani is also using less-invasive methods of harvesting stem cells from placental blood and from peripheral blood drawn from veins.

"The bone marrow is the organ in the body where all the blood cells are manufactured," explained Dr. Kamani. "There are three types of cells--white blood cells, red blood cells and platelets--that circulate in our blood. They all arise from a single cell of the bone marrow, called the stem cell, which is like a seed that gives rise to these three different types of blood cells. So, if you can get stem cells from a donor, you can basically replace a patient's bone marrow with those stem cells."

Researchers found that umbilical cord blood has numerous stem cells and that enough blood from the placental vein could be collected for a stem cell transplant in a small child, explained Dr. Kamani. Usually, placentas have just been discarded following birth. That practice is changing, he added, now that four or five cord blood banks have been set up in the United States.

Potential donor mothers are asked about family history of disease, to make sure the cord blood does not carry a genetic disease, and are asked to sign a consent form. The painless donation does not interfere with the birthing process, and the 2 to 5 oz. of collected blood is checked for infection, typed according to tissue and frozen for future use.

Eddie became a candidate for the program's first cord blood transplant when more traditional searches for a bone marrow match failed to produce a donor. "The matching we're talking about is at the tissue type level," Dr. Kamani said, "and there are more than a million different tissue types.

"Only about 25 percent of patients will have donors in their families; for the other 75 percent we search for a stem cell donor outside the family. We find donors for about 80 to 85 percent of our Caucasian patients, about 50 to 60 percent of our Hispanic patients and about 30 to 50 percent of our African American patients." Dr. Kamani added that just five years ago, it was rare to find donors for Hispanic or African American patients. Because of the recruitment of minority donors by the South Texas Blood and Tissue Center, and other similar institutions around the country, the situation has improved.

When the placental blood transplant became a possibility, Eddie's parents, Olga and Roger Benavides, consented to the procedure. Now several months following the successful transplant, Eddie routinely visits Dr. Kamani. "Before the transplant Eddie was always very tired," Mrs. Benavides commented during one of those visits. "Even when we went to a restaurant, he would want to lie down in the chair. Today, Eddie is tired because he stayed up late playing video games. We're very lucky--we had such good doctors."

Over the past 10 years, physicians and researchers also have discovered that stem cells can be mobilized to come out of the bone marrow into the peripheral blood by giving the donor the drug Neupogen™, explained Dr. Kamani. A large catheter, which is attached to a machine that can extract stem cells from the blood, is placed in a donor's vein after Neupogen™ and local anesthesia are administered. The process is considered safer than a traditional bone marrow harvest from the donor's pelvis, because the harvest usually requires general anesthesia. The patient receives the stem cells through a venous catheter.

While bone marrow transplants or stem cell transplants most commonly are used to treat leukemia, other cancers and many different types of childhood diseases are responsive to these treatments, according to Dr. Kamani. "If a child is given very high doses of chemotherapy and radiation to wipe out a particular cancer, the radiation and chemotherapy also wipe out the child's bone marrow," Dr. Kamani said. "You have to give them someone else's bone marrow; otherwise, their cancer may go away, but they'll die because their bone marrow also has gone away."

Dr. Kamani also performs bone marrow transplants for children born with immunodeficiency, certain genetic diseases and non-malignant diseases of the blood and bone marrow. Four rooms, which have been equipped with special air flow systems to protect against infections, are set aside in the hospital for the bone marrow transplant patients.

Regardless of transplant technique, superb physicians and extraordinary facilities, bone marrow transplants still require donors. "More bone marrow donors mean more children's lives can be saved," concluded Dr. Kamani.

Potential bone marrow donors
may telephone the South Texas Blood and Tissue Center
at 1-800-292-5534.

"More bone marrow donors mean more children’s lives can be saved."
--Dr. Kamani

Giving children new hope with new drugs

Arrow Children's cancer warning signs

Arrow The Britton Center--everything under one roof

Arrow Cancer survivor tells others--'It's going to get better'

Arrow Return to index--Fall 1998