Soluble interleukin-2 receptor level as an indicator of liver allograft rejection

We studied the serum levels of soluble interleukin-2 receptors (SIL-2R) in liver allograft recipients: a control group without rejection or CMV disease, a group with only rejection episodes, and a group with only cytomegalovirus disease. Rejection was diagnosed by the presence of compatible laboratory and histologic abnormalities and absence of other causes of graft dysfunction. CMV disease was diagnosed by isolation of CMV in blood or liver specimen cultures or identification of cytomegalic inclusions in the liver biopsy specimen. Of 82 consecutive recipients treated with cyclosporine and prednisone, 12 were in the control group, 20 in the rejection group, and 5 in the CMV disease group. The remaining 45 had other or multiple complications. In the control group the SIL-2R levels (determined by an ELISA) decreased by a mean of 4% per day after transplantation; in the rejection group the levels increased by a mean of 17% per day in the 10 days prior to the diagnosis of rejection; in the CMV disease group the levels tended to increase prior to the diagnosis of CMV disease. The rejection group had significantly higher SIL-2R levels than the control group at comparable times. Thus, SIL-2R levels were significantly increased at the time of allograft rejection compared with levels in a control group, and recipients with CMV disease had increased levels of SIL-2R but they were not as high as in recipients with rejection episodes.