LAUSR

504Background: Metastatic renal cell cancer (mRCC) patients are afflicted with the immunosuppressed condition, and myeloid-derived suppressor cells (MDSCs) are considered to be associated with this condition. MDSCs are difficult to detect in peripheral blood as their cell structures are not uniform, resembling both neutrophils and monocytes. GPI-80 is known as a regulator of Mac-1 (CD11b/CD18) and closely related with neutrophilic maturation. In this study, we investigated whether the pattern of GPI-80 expression could serve as a useful marker for the detection of MDSCs in peripheral blood among mRCC patients. Methods: This study was approved by the Ethics Committee of Yamagata University’s Faculty of Medicine. Peripheral blood samples, collected from 12 mRCC patients before treatment and 12 healthy volunteers, were stained with several differentiation markers such as CD11b, CD16, CD15, CD33, and GPI-80. The samples were examined using flow cytometry to detect unusual differentiation of myeloid cells. To ...