BACKGROUND: Kimura's disease is a rare but distinctive eosinophilic inflammatory disorder of unknown etiology; few reported case studies have focused on the immunopathologic background of this unique disease. OBJECTIVE: To define better the immunopathogenetic features of Kimura's disease, we attempted to quantitatively analyze values of cytokines and soluble interleukin-2 receptor (sIL-2R) in peripheral blood (PB), as well as perform surface immunophenotypic analysis of eosinophils from a Japanese patient with chronic relapsing Kimura's disease. RESULTS: Granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and sIL-2R were elevated, and newly expressed antigens on eosinophils CD4, CD25, and HLA-DR were found to be involved in the pathophysiology of this disorder. CONCLUSIONS: Kimura's disease may be a disease in which activated lymphocytes release cytokines, and these released cytokines, such as GM-CSF and TNF-alpha cause eosinophil activation. These processes may be related to the pathogenesis of this disorder.