Lohse, Christine M.

AbstractPurpose: Regulatory T cells (Tregs) have been implicated as inhibitors of antitumoral immunity, and evidence suggests that elimination of Tregs may augment natural and pharmacologic immunity. We tested for the presence of putative Tregs within renal cell carcinoma (RCC) tumors.Experimental Design: We identified 170 patients who underwent radical or partial nephrectomy for clear cell RCC between 2000 and 2002. Specimens were stained with anti-CD4, anti-CD25, and anti-Foxp3 antibodies and examined using confocal microscopy. Associations of CD4+CD25+Foxp3− and CD4+CD25+Foxp3+ T cells with death from RCC were evaluated using Cox proportional hazards regression models.Results: At last follow-up, 46 of 170 patients had died; of these, 37 died from RCC at a median of 1.4 years following nephrectomy (range, 0-4.4). Among the 124 remaining patients, median follow-up was 3.7 years (range, 0-5.7). Forty-three (25.3%) tumors harbored CD4+CD25+Foxp3+ T cells. The presence of Foxp3+ T cells was not significantly associated with RCC death univariately. One hundred forty-three (84.1%) tumors harbored CD4+CD25+Foxp3− T cells. The indicator for ≥10% CD4+CD25+Foxp3− T cells was significantly associated with RCC death univariately [risk ratio (RR), 2.60; 95% confidence interval (95% CI), 1.35-4.98; P = 0.004], after adjusting for tumor B7-H1 expression (RR, 2.53; 95% CI, 1.32-4.85; P = 0.005) and lymphocytic infiltration (RR, 2.53; 95% CI, 1.32-4.87; P = 0.005).Conclusions: Increased presence of CD4+CD25+Foxp3+ T cells was not significantly associated with RCC death. In contrast, CD4+CD25+Foxp3− T cells, which may represent a unique set of Tregs or activated helper T cells, was significantly associated with outcome.

AbstractPurpose: Clear cell renal cell carcinoma (ccRCC) is an immunogenic tumor that can progress in the presence of an intact host immune system. We previously reported that survivin and B7-H1 are independently associated with disease progression and death when expressed by ccRCC tumors. Herein, we examine the clinical effect of ccRCC combined expression of both survivin and B7-H1.Experimental Design: Specimens from 298 patients who underwent nephrectomy for ccRCC between 1990 and 1994 were immunohistochemically stained for survivin and B7-H1. Cancer-specific survival was estimated using the Kaplan-Meier method. Associations of both markers with ccRCC death were assessed using Cox proportional hazards regression models.Results: At last follow-up, 94 patients died from ccRCC. Among the living patients, the median follow-up was 11.2 years (range, 0-15 years). There were 177 (59.4%) survivinLow/B7-H1−, 51 (17.1%) survivinHi/B7-H1−, 29 (9.7%) survivinLow/B7-H1+, and 41 (13.8%) survivinHi/B7-H1+ tumors. The 5-year cancer-specific survival rates for patients within each group were 89.3%, 59.7%, 70.0%, and 16.2%, respectively. Combined survivinHi/B7-H1+ expression was associated with ccRCC death univariately (risk ratio, 12.82; 95% confidence interval, 7.50-21.92; P < 0.001) and in multivariate analysis (risk ratio, 2.81; 95% confidence interval, 1.56-5.04; P < 0.001). SurvivinHi/B7-H1+ tumors exhibited increased levels of infiltrating mononuclear cells and survivin-specific T cells compared with survivinLow/B7-H1− tumors.Conclusion: Patients with survivinHi/B7-H1+ ccRCC tumors are at increased risk of ccRCC death. SurvivinHi/B7-H1+ tumors also harbor increased amounts of infiltrating mononuclear cells and survivin-specific T cells relative to survivinLow/B7-H1− tumors. Taken together, dual expression of survivin and B7-H1 can be used to predict ccRCC tumor aggressiveness.

Abstract Purpose: B7-H1 is expressed by clinically aggressive forms of renal cell carcinoma (RCC) and predicts adverse outcome. B7-H1 is known to impair host immunity via interaction with the Programmed Death-1 (PD-1) receptor, which is expressed by activated T cells. Levels of immune cells expressing PD-1 (PD-1+) in clinical RCC tumors have not been evaluated. Thus, we tested whether immune cell PD-1 expression is observed within aggressive RCC tumors. Experimental Design: Between 2000 and 2003, 267 patients underwent nephrectomy at our institution for clear cell RCC and had fresh-frozen tissue available for review. These RCC specimens were immunostained using anti–PD-1 (clone MIH4) and outcome analyses were conducted. Results: Mononuclear immune cell infiltration was observed in 136 (50.9%) specimens. PD-1+ immune cells were present in 77 of these 136 (56.6%) tumors. In contrast, RCC tumor cells did not express PD-1. Patients with PD-1+ immune cells were significantly more likely to harbor B7-H1+ tumor cells (P < 0.001), larger tumors (P = 0.001), and tumors of higher nuclear grade (P = 0.001). Likewise, intratumoral PD-1+ immune cells were associated with advanced tumor-node-metastasis stage (P = 0.005), coagulative tumor necrosis (P = 0.027), and sarcomatoid differentiation (P = 0.008). With a median follow-up of 2.9 years, 52 patients died from RCC. Univariately, patients with PD-1+ immune cells were at significant risk of cancer-specific death compared with PD-1− patients (risk ratio, 2.24; P = 0.004). Conclusions: Levels of immune cells expressing PD-1 were increased in patients with high-risk RCC tumors. Interactions between immune cell PD-1 and B7-H1 may promote cancer progression by contributing to immune dysfunction in patients with RCC.