Infant Heart Transplants Possible Among Incompatible Blood Types

Researchers reported at the American Heart Association’s Scientific Sessions 2007 that the heart transplants between incompatible blood types, AB-O, can be safely carried out among infants, with ages one or below. As based on the national data submitted to the United Network for Organ Sharing (UNOS), the analysis showed that the level of safety in performing infant heart transplants among those with incompatible blood types is similar to that of heart transplants among those with compatible blood types.

The senior author of the research, Luca A. Vricella, M.D., the chief of pediatric heart transplantation at Johns Hopkins Medical Institutions in Baltimore, said that there was no difference in the results of the study on compatible and incompatible transplants among the infants. Nishant Patel, B.A., a third-year medical student, added that the similar survival levels between the two groups were similar at three years.

Patel went on further to remark that the performing ABO-incompatible heart transplant procedure is not dangerous in infants, as it resulted to low incidence of hyperacute rejection. Hyperacute rejection or transplant rejection is the condition wherein the immune system of a transplant recipient damages the organ or tissue that has been placed into his body. Patel, who presented the findings of the study to the said session, also recommended that the procedure of ABO-incompatible heart transplant should be considered in infants in order to take advantage of the donor organ utilization and lower infant mortality.

In addition to that, Vricella said that the use of incompatible donor hearts has the potential of reducing the number of infants, who die while waiting for the availability of donor hearts. Vricella reported that employing incompatible donor hearts in transplant can reduce infant mortality by at least twenty percent. As such, there shall be an enormous effect because infants no longer need to rely on the small donor pool available.

Up to forty percent of infants on the waiting list for donor hearts die while as they wait for a donor heart to become available. Moreover, the average waiting time for such availabiltiy exceeds two months.

One key factor why incompatible transplant works in infants is the role of antibodies, known as isohemagglutinins. Isohemagglutinins are the substances responsible in fastening red blood cells.

Since infants have underdeveloped immune systems until age twelve to fourteen months, isohemagglutinins are not yet produced or only a small amount of which is produced. As such, these antibodies could not affect the donor heart. This results to the significant decrease of hyperacute rejection.

Live blood cell analysis or live blood analysis plays a significant role in procedures, such as infant heart transplants. Since the blood is still alive in performing live blood analysis, occurrences can be observed such as that of yeasts, molds, bacteria, parasites, immune system activity, allergies, hormonal imbalances, and sugar intolerances, among others.

By definition, live blood analysis is the observation and examination of live blood cells with the assistance of a high resolution darkfield compound microscope. This procedure of inspection is commonly known as darkfield microscopy.

Live blood analysis starts with taking a blood sample through a tiny pin prick on the fingertip. Such single drop of blood sample is placed under a specially adapted microscope, known as the darkfield compound microscope. A darkfield compound microscope is a high powered piece of equipment that is fashioned with a darkfield condenser, that lights the biological samples from the sides, not from the below. With the help of an attached camera, a darkfield compound microscope is connected to a video screen for better viewing. The image seen on the video screen is the 20,000 times magnification of the tiny blood sample. As such, with the use of a darkfield compound microscope, health care providers can check for the presence and/or the amount of isohemagglutinins that are crucial in the success of an infant heart transplant procedure.