Down-regulation of human leukocyte antigen class I (HLA-I) is associated with poor prognosis in patients with clear cell renal cell carcinoma.

Human leukocyte antigen class I (HLA-I) molecules are transmembrane glycoproteins that have been reported to be down-regulated in multiple types of human malignancies, including clear cell renal cell carcinoma (CCRCC). However, only one study has investigated its prognostic value in CCRCC. In the present study, HLA-I protein expression was analyzed in 120 archived, paraffin-embedded CCRCC samples and 10 adjacent normal tissues using immunohistochemistry. The correlation between HLA-I expression and clinicopathological factors was evaluated by the χ(2) test. Patients' overall survival was analyzed by the Kaplan-Meier method. HLA-I down-regulation was observed in 38.3% (46/120) of renal tumor samples, but only in 10% (1/10) of adjacent normal tissues. Statistical analysis showed a significant correlation of HLA-I expression with TNM stage, lymph node metastasis, and Fuhrman grade. Patients with tumors displaying down-regulation of HLA-I showed significantly shorter overall survival (P=0.021, log-rank test). More importantly, multivariate analysis indicated that down-regulation of HLA-I was an independent prognostic factor for CCRCC patients (P=0.033). Overall, our data suggest that HLA-I down-regulation is associated with tumor progression and a poor prognosis in CCRCC patients, and emphasize the importance of HLA-I in natural and therapeutic immune surveillance of patients with CCRCC.