WASHINGTON—Receiving an organ low in weight in relation to the recipient’s body weight increases kidney transplant recipients risk of complications and transplant failure, according to a study appearing online May 20 in the Journal of the American Society Nephrology (JASN).
The results suggest that compatibility between a donated kidney’s weight and the weight of the recipient could improve the success of transplantation.
Few studies have examined the direct impact of matching a donated kidney’s weight to the weight of a transplant recipient. To investigate, Professor Jean Paul Soulillou (Institut National de la Santé Et de la Recherche Médicale (INSERM) Unité 643 and Institut de Transplantation Et de Recherche en Transplantation (ITERT), in Nantes, France) and his colleagues studied how kidney weight to recipient weight ratios affect the long-term kidney health of individuals who receive transplants.
After following 1189 patients for an average of 6.2 years after transplantation, the investigators found that the greater the incompatibilities of weight ratios, the more likely patients were to develop kidney problems. Specifically, a low kidney weight to recipient weight ratio (<2.3 g/kg) increased the risk of developing inadequate kidney filtration, excess urinary protein excretion, hypertension, kidney scarring, and transplant failure. This low kidney weight to recipient weight ratio was associated with a 55 percent increased risk of transplant failure after two years of follow-up.
“This information is potentially useful for thousands of transplantations and provides a new opportunity to improve long-term graft survival,” said Soulillou. He added that the clinical impact of the kidney weight to recipient weight ratio is similar to what was described decades ago for human leukocyte antigens, which are the major compatibility markers used today to determine transplant-recipient matches.
In reviewing the results of Soulillou’s study in an accompanying editorial, Ron Shapiro, MD (University of Pittsburgh) stated that “the authors are to be congratulated for describing a novel measure that may have important implications for long-term outcomes in renal allograft recipients.” He noted, however, that because living donors made up less than 1 percent of the study’s cases, it is not clear if the findings hold true for recipients other than those who receive deceased donor kidneys.
