A Lifesaving Change in Procedure

In 2006, nearly 3,700 patients in the northern three-quarters of Illinois and northwest Indiana needed kidney transplants. Due to their high level of immunological sensitization, (the likelihood  a patient’s body will reject a transplant) 520 of these patients were half as likely as other patients to find a suitable donor. Four years later, nearly three times as many of these highly sensitized patients found donors. The jump was neither biological phenomena nor the result of an unprecedented donor supply. Instead, it was the benefit of a new scientific process—a process pioneered by Dr. Andrés Jaramillo, director of the histocompatibility and immunogenetics laboratory at Gift of Hope Organ & Tissue Donor Network. His procedure is giving hope to an ever-growing list of patients waiting for life saving organ transplants.

A scientist may work on diseases such as diabetes or cancer for decades, seeing little improvement. But the benefits of transplantation are often immediate. After years of working in basic immunology research, Jaramillo was drawn to clinical transplant immunology for just that reason. With research background in Canada, South America, and the United States, Gift of Hope was a perfect match for him.

When he joined Gift of Hope in 2007, the histocompatibility and immunogenetics laboratory had been testing donors and patients with the same method since the 1960s: a series of time-consuming steps yielding results that were not always accurate. Donors had to be screened for infectious diseases, genetically analyzed, and cross matched with patients in the organ transplant waiting list. The whole process took about 16 hours— precious time when the viability of organs is considered. Though kidneys can remain viable for as long as 36 hours after recovery in cold ischemia preservation, other organs are not nearly as resilient. The liver, pancreas, and small intestine can last only about eight hours, and the heart and lungs no longer than four.

Jaramillo introduced Gift of Hope to polymerase chain reaction (PCR) and virtual cross matching technology. PCR is used to screen a particular region of chromosome 6, where the genes of the human leukocyte antigen (HLA) system are found. HLA must match between donor and recipient during a transplant, or the immune system will produce antibodies against the graft, causing organ rejection. Virtual cross matching uses a computer to instantly predict patients’ compatibility with donors, based on the results of the PCR, and match them. Now in fewer than six hours, Jaramillo and his team can determine donors’ HLA profiles and cross match them accurately against potential recipients in the organ waiting lists—a breakthrough that is helping broaden the footprint of viable organs waiting to be donated but formerly constrained by preservation limits.

Approximately one-third of patients who need transplants are considered sensitized. This means that when their anti-HLA antibody profile is compared with the donor pool, they will be incompatible with anywhere from 10 to 100 percent of donors. Beyond the antibodies they are genetically predisposed to generate, they may have additional antibodies against HLA because of previous transplants, blood transfusions, or pregnancies. Patients tend to be most compatible with donors of the same race, but because the donor pool in the United States is overwhelmingly Caucasian, minorities such as Hispanics have a smaller chance of finding a match. “Women,” says Jaramillo, “especially of Hispanic and African-American descent, are at a disadvantage in the transplant system because they have fewer match potentials, and they tend to have more children.”

In the past, sensitized patients could remain on the organ transplant waiting list for years without finding a match. Virtual cross matching, which relies on current, highly specific records of patients’ anti-HLA antibodies, expands the donor pool. Its speed and accuracy improve the likelihood of successfully matching patients and donors who would have never previously been matched.

While reducing testing times and finding more matches for sensitized patients have broadened horizons for those waiting for organ transplants, the work that has impacted Jaramillo personally goes beyond the laboratory.

Luis Ángel Pérez was a Chicago teenager when he lost his life. “His family told us about his involvement in gang activity,” recalls Jaramillo, “but he had registered as a donor before he passed.”

His organs were donated to six people, including a mother of three who received Luis’s heart after waiting a year for a match. To know that a loved one’s heart is beating for another provides a unique kind of closure that Jaramillo is proud to have aided. “Even though it was a painful experience for [Luis’s] family, in a way, they felt that he redeemed himself through his donation,” says Jaramillo. “I witnessed how the process of donation gives families a joyful outcome that can help ease their grief.”