ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of CD33⁺ HLA-DR⁻ myeloid-derived suppressor cells (MDSCs) in the peripheral blood of patients with renal carcinoma and its correlation with the clinicopathological features of renal cancer.</p><p><b>METHODS</b>Forty-four patients with renal carcinoma treated in our hospital between June, 2011 and October, 2012 and 18 healthy volunteers were enrolled in this study. Flow cytometry was performed to detect CD33⁺ HLA-DR⁻ MDSCs in the peripheral blood, and its correlation with the clinicopathological features of the patients were analyzed.</p><p><b>RESULTS</b>The positivity rate of CD33⁺ HLA-DR⁻ MDSCs in the peripheral blood was significantly higher in the cancer patients than in the healthy controls [(1.91 ± 0.66)% vs (0.62 ± 0.22)%, P<0.001]. The expression levels of CD33⁺ HLA-DR⁻ MDSCs in patients with renal carcinoma showed significant differences between stage I+II [(1.46 ± 0.44)%] and stage III [(2.04 ± 0.35)%] patients (P<0.01) and between stage III and stage IV patients [(2.50 ± 0.64)%] (P<0.05), but did not differ significantly in respect of age or gender.</p><p><b>CONCLUSION</b>CD33⁺ HLA-DR⁻ MDSCs expression in the peripheral blood is associated with tumor stage and differentiation in renal carcinoma and may play an important role in predicting the prognosis and tumor immunology of renal carcinoma.</p>