Elevated soluble interleukin 2 receptor levels found among kidney transplant recipients

Although previous studies have not demonstrated a clear correlation between interleukin (IL) 2 receptor levels and immunological events after transplantation, many still suggest that these levels have clinical utility. A total of 759 serial measurements of both IL-2R and creatinine were compared over time and correlated with rejection episodes, clinical course, and immunosuppression. The profiles for the 40 patients showed several patterns, including correlation with changes in creatinine levels or with renal dysfunction, peaks in the absence of clinical findings, and discordant IL-2R and creatinine levels. Wide baseline variations in IL-2R levels confounded comparison of mean values and definition of a statistically significant rise. While tending to correlate with immunological events, elevations in IL-2R also occurred in clinically normal patients. IL-2R appears to lack specificity for immunological events. Thus, we conclude that IL-2R measurement does not have clinical diagnostic utility for monitoring renal transplant recipients.