A detailed examination of the degree of tissue type mismatch between organ donors and recipients can help determine how much immunosuppressive medication an individual transplant recipient will need after transplantation, according to a study published in the Journal of the American Society of Nephrology (JASN).

Chris Wiebe MSc, MD, FRCPC, from the University of Manitoba and Health Sciences Centre Winnipeg, in Canada and his colleagues looked to see if the extent of mismatch in the tissues of the donor and the recipient, when studied at the molecular level, would provide a method to help determine immunosuppressive dosing.

The investigators analyzed more than 50,000 medication levels in 596 kidney transplant recipients in the context of the degree of molecular mismatch between recipients and their donors. After following patients for a median of seven years, the researchers discovered a strong correlation between the percentage of medication levels that were low and the development of antibodies against the transplanted kidney.

Low medication levels were better tolerated in patients who had a low molecular mismatch with the donor, whereas patients who had a high molecular mismatch score were more likely to develop antibodies unless they were maintained at higher medication levels.

“Recent advances in transplantation have allowed physicians to understand the degree of tissue type mismatch between donors and recipients at a much more detailed level than ever before,” said Wiebe. “Using the results from this study, physicians now may be able to select medication doses tailored to the individual instead of treating all patients the same way.”

Study co-authors include David Rush, MD, FRCPC, Thomas Nevins, MD, Patricia Birk, MD, FRCPC, Tom Blydt-Hansen, MD, FRCPC, Ian Gibson, Sc, MBChB, MD, FRCPath, Aviva Goldberg, MA, MD, FRCPC, Julie Ho, MD, FRCPC, Martin Karpinski, MD, FRCPC, Denise Pochinco, MLT, Atul Sharma, BSc, MStat, MD, FRCPC, Leroy Storsley, MD, FRCPC, Arthur Matas MD, and Peter Nickerson, MD, FRCPC.