Objectives: To further our understanding of the potential protective effects of one organ allograft for another in combined organ transplants by comparing rejection-free survival and the 1-year rejection rate of each type of combined organ transplant.
Summary Background Data: Liver allografts have been thought to be immunoprotective of other donor-specific allografts. Recent observations have extended this property to other organs.
Methods: Analysis of data from the United Network of Organ Sharing included recipients 18 years or older (except those receiving intestinal transplants) transplanted between January 1, 1994, and October 6, 2005, and excluded those with a previous transplant (n = 45,306), live-donor transplant (n = 80,850), or insufficient follow-up (n = 4304). Patients were followed from transplant until death (n = 41,524), retransplantation (n = 4649), or last follow-up (n = 87,243).
Results: A total of 133,416 patients were analyzed. Rejection rates for allografts co-transplanted with donor-specific primary liver, kidney, and heart allografts are significantly lower than rejection rates for allografts transplanted alone. Allografts accompanying primary intestinal or pancreatic allografts did not have reduced rejection rates. A decreased rate of rejection was seen in interval kidney-heart transplants when allografts shared partial antigenic identity. Decreased rates of rejection were also seen in transplants of 2 donor-specific organs of the same type.
Conclusions: In combined simultaneous transplants, heart, liver, and kidney allografts are themselves protected and protect the other organ from rejection. Analysis of interval heart-kidney allografts suggests the need for partial antigenic identity between organs for the immunoprotection to take effect. This was not demonstrated in interval liver-kidney transplants. Increased antigen load of identical antigens, as seen in double-lung and double-kidney transplants, also offers immunologic protection against rejection.
We analyzed data on 133,416 recipients of single or combined organ transplants for protective effects against rejection of one organ for another. The data revealed that not only the liver but also renal and cardiac allografts have immunoprotective potential. Double kidney and lung transplants also manifested immunoprotection, suggesting a possible role for antigenic load.
From the Divisions of *Transplant Surgery, †Cardiothoracic Surgery, and ‡International Center for Health Outcomes and Innovation Research, Department of Surgery, Columbia University College of Physicians and Surgeons, New York, New York.
This work was supported in part by the National Institutes of Health training Grant T32HL07854-11 (to A.R.) and by Health Resources and Services Administration contract 231-00-0115.
The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Health and Human Services or the National Institutes of Health, nor does the mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.
Reprints: Abbas Rana, MD, Division of Transplant Surgery, Department of Surgery, Columbia University College of Physicians and Surgeons, New York, NY 10032. E-mail: email@example.com.