National kidney allograft sharing: a decision analysis

Area of Science:

• Nephrology
• Transplantation immunology
• Health services research

Background:

• Current national sharing of cadaveric kidney allografts has uncertain benefits.
• Significant logistical barriers exist for expanding organ sharing programs.
• This study quantifies potential allograft survival improvements from expanded sharing in the U.S.

Purpose of the Study:

• To estimate the improvement in kidney allograft survival achievable by expanding national organ sharing.
• To compare different national sharing strategies based on histocompatibility matching.

Main Methods:

• Decision analysis model comparing four sharing strategies: no sharing, sharing at 6, 4, or 2 histocompatibility alleles.
• Utilized national cadaveric kidney allograft recipient survival data.
• Compared impact of sharing strategies to the effect of cyclosporine on transplant outcomes.

Main Results:

• Sharing allografts matched at 4 or more alleles yielded optimal mean survival (6.35 years).
• This optimal strategy offered only a marginal improvement (<2% increase in 4-year survival) over no national sharing (6.21 years).
• Cyclosporine significantly improved mean allograft survival (6.07 years) compared to pre-cyclosporine era (3.79 years), far exceeding potential gains from expanded sharing.

Conclusions:

• Expanding national allograft sharing provides limited improvement in mean allograft survival.
• The minimal benefits and logistical barriers necessitate careful consideration before expanding U.S. organ sharing.
• Cyclosporine's impact on kidney transplant survival is substantially greater than that of expanded national sharing.