Interleukin-6 (IL-6) has diagnostic importance as one of the earliest indicators of inflammation, tissue damage, hypoxia, or infection. In contrast to the time-consuming immunoassays actually used in many laboratories, results of a new IL-6 bedside test, which is interpreted visually or photometrically, are available at 20 minutes. The photometric measurement using a stored standard curve allowed differentiation of five ranges: < 50, 50-100, > 100-200, > 200-500, and > 500-1000 pg/mL. The aim of our study was to evaluate the diagnostic relevance of this new IL-6 bedside test in four well-defined, noninfectious and infectious events after kidney transplantation. In a retrospective study the IL-6 serum levels were measured in a total of 269 serum samples from 27 renal graft recipients. Analysis of all data clearly showed that the majority of elevated IL-6 levels occurred in connection with bacterial infections. Viral infections did not result in an increase of IL-6 > 50 pg/mL. Thus, from a clinical point of view this new bedside test can be recommended.
