PITTSBURGH, Dec. 23 -- The process by which the human immune system takes little notice of certain infections is similar to the way it takes little notice of a transplanted organ under the most perfect immunological conditions, say two authors, one a Nobel laureate and the other the "father of transplantation," in this week's New England Journal of Medicine.

Thomas E. Starzl, M.D., Ph.D., professor of surgery and director, University of Pittsburgh Thomas E. Starzl Transplantation Institute; and Rolf M. Zinkernagel, M.D., professor of pathology and director, Institute for Experimental Immunology, University of Zurich, report that the mechanisms by which certain micro-organisms are able to exist in the human host closely resemble the mechanisms that confer permanent acceptance of a transplanted organ.

That antigens-foreign substances like those in micro-organisms and cells from a donor organ-migrate through the body to take up residence in various tissues is the common thread that explains how the body's immune system responds to both infectious diseases and organ transplants. The authors say this mechanism, involving a delicate balancing act, governs the immune system's response or nonresponse against infections, tumors, self, and transplanted organs from either human or animal donors.

"Although the relation between infection and transplantation immunity is complicated, the mechanisms and rules are basically the same," the authors write.

The review article is a convergence of theories from two separate medical specialties and draws upon the seminal works of Drs. Starzl and Zinkernagel.

In a 1992 Lancet article, Dr. Starzl observed that chimerism-the coexistence of donor and recipient immune cells-was a condition present in transplant recipients who had survived with their transplanted organs for up to 29 years. Donor leukocytes (white blood cells) and dendritic cells, which originate in bone
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Contact: Lisa Rossi
rossiL@msx.upmc.edu
412-647-3555
University of Pittsburgh Medical Center
23-Dec-1998