Gene Expression Identified for Kidney Transplant Patients

A distinct pattern of gene expression in kidney transplant recipients will help identify other transplant recipients who could safely reduce or end use of immunosuppressive therapy.

A study to determine gene expression patterns included three groups: 25 kidney transplant recipients who had ceased taking immunosuppressive drugs and had retained normal kidney function for more than one year; recipients who were still taking their immunosuppressive medication and had healthy kidneys; and healthy, nontransplant controls.

Scientists analyzed the gene expression of cells in whole blood and noted that the transplant recipients who were not taking medication had a distinct pattern of genes expressed by B cells, a type of white blood cell. This pattern differed from those seen in participants who were still on immunosuppressive therapy and in nontransplant, healthy control subjects. Further study identified a pattern of expression of three B cell genes that was far more common in patients who had stopped taking their medications yet maintained good graft function.

Following a kidney transplant, recipients must be placed on immunosuppressive therapy or their immune systems will reject the transplanted organ. However, these drugs suppress the entire immune system, reducing an individual's ability to fight infections, and sometimes leading to diseases related to a weakened immune system, such as cancer. The drugs also have other severe side effects such as diabetes, hypertension, and heart disease, as well as swelling, weight gain, and excessive hair growth, and acne that many people find intolerable.

The study team included three lead investigators, Kenneth Newell, M.D., Ph.D., of Emory University (Atlanta, GA, USA) Laurence Turka, M.D., of Beth Israel Deaconess Medical Center (Boston, MA, USA) and Harvard Medical School (Boston, MA, USA), and Vicki Seyfert-Margolis, Ph.D., at the U.S. Food and Drug Administration (FDA; Silver Springs, MD, USA).

The report appears online in the May 24, 2010 edition of the Journal of Clinical Investigation.

Related Links:
Emory University
Beth Israel Deaconess Medical Center
Harvard Medical School
U.S. Food and Drug Administration