Abstract. Both inflammatory and anti-inflammatory cytokines have been reported to be associated with acute graft-versushost disease (aGVHD). However, their role and possible mutual interactions during aGVHD are not well understood. Eight patients with aGVHD and eight without who had undergone allogeneic HLA-identical peripheral blood stem cell transplantation were studied. The patients had no other complications known to affect serum concentration of cytokines, including infection. Serum concentrations of IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, TNF-· and IFN-Á were concurrently measured by a new technique, the cytometric bead array (CBA). We found that serum concentrations of IL-5, IL-6 and IL-10 were significantly higher in patients with aGVHD than in patients without it. By ratiometric analysis, the ratios of IL-5/IL-2, IL-5/IL-4, IL-6/ IL-4 in patients with aGVHD were increased compared to the patients with no evidence of aGVHD. ROC analysis demonstrated that the ratio of IL-5/IL-4 was the most sensitive parameter associated with aGVHD. The second best marker of aGVHD was increased IL-5 concentration. Thus, our results indicate that the ratio of a particular cytokine/ cytokine could be a potential diagnostic marker for aGVHD, more sensitive that the serum level of a given cytokine. This observation is consistent with a cross-talk among some cytokines and their possible interactions via respective receptors on cytokine-producing cells; these interactions may play an important role in pathogenesis of aGVHD. Further studies including a large number of patients and concurrent measurement of a variety of cytokines are needed to fully assess the diagnostic value of the cytokine ratiometric analysis. The CBA methodology provides a convenient and useful tool in such studies.

Inflammatory effectors by recipient cells, rather than allogeneic responses by donor cells, played an important role in the pathogenesis of NIPCs after DLI in the present case.