St. Louis, May 17, 1999 -- A study of thousands of kidney transplants suggests that the long-term cost of caring for patients could drop dramatically if more received kidneys closely resembling their own organs.
Doctors are debating the importance of transplanting organs whose surface proteins are identical to a patient's other organs. Previous studies suggested that multiple differences in the surface markers, called HLA markers, had little effect on kidney rejection of transplanted kidneys.
In the new study of 27,050 kidney transplants, the investigators demonstrated a significant increase in the need for care within three years of transplantation as the number of mismatched surface markers increased.
"Although the transplanted kidney remains functional in patients with more mismatches, the patient doesn't do as well, and that fact makes it much more costly," says economist Mark A. Schnitzler, Ph.D., a research instructor at Washington University School of Medicine in St. Louis. Schnitzler will present the findings May 17 at the annual meeting of the American Society of Transplantation in Chicago.
Schnitzler and colleagues in the medical school's Pharmaco-Economic Transplant Research group compared national kidney transplant records from the United Network on Organ Sharing (UNOS) with Medicare claims for the same patients. All 27,050 had received an organ from a deceased donor between 1992 and 1997. They determined the cost of their care from 30 days after transplant until three years after transplantation.
The average cost to Medicare -- and thus to taxpayers -- of care within three years was roughly $60,436 when the kidney had identical HLA markers to the patient's own organs. The cost rose by 5 percent to 34 percent as the number of mismatches increased from one to six: UNOS gives a patient on the national waiting list top priority for a donor kidney anywhere in the United States that has identical surface markers. The network also promotes the use of donor organs with few mismatches, but it does not discourage use of organs with more mismatched surface markers.
By itself, the data could be used to argue that all donor kidneys should be available nationally so less mismatched transplants occur. Congress is debating the merits of such a distribution system out of concern that some patients lose out on a well-matched organ in the current, regional distribution system.
The research being presented by Schnitzler was part of a debate two weeks ago on this topic by the House Subcommittee on Health and Environment.
Schnitzler notes, however, that additional analyses from the study funded by pharmaceutical companies suggest that national organ sharing is unnecessary and makes care costlier. The problem is that kidneys deteriorate during transport from a distant location.
"You could match kidneys better locally, and you could match even better nationally, but not better enough to compensate for organ deterioration," Schnitzler says.
However, kidney recipients have the benefit of undergoing dialysis treatments, which can give them time to wait for a good local match. This may not apply to people needing lungs and other organs.
| Number of Mismatches | Average Cost, Care for 5 Years | % Increase in Average Cost |
|---|---|---|