Leite Katia R M, Reis Sabrina T, Junior José Pontes, Zerati Marcelo, Gomes Daniel de Oliveira, Camara-Lopes Luiz H, Srougi Miguel
Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil.
Department of Molecular Biology, Genoa Biotecnologia SA, Av Dr. Arnaldo #455, room 2145, 01246-903, Sao Paulo, Brazil.
Diagn Pathol. 2015 Oct 15;10:189. doi: 10.1186/s13000-015-0414-x.
PD-L1 is a glycoprotein from the family of T-cell co-stimulatory molecules that are constitutively expressed by macrophages. Aberrant expression of PD-L1 is observed in human cancers associated with inhibition of the tumor-directed T-cell immune response. There are few reports in the literature evaluating PD-L1 expression in association to prognosis specifically in renal cell cancer clear cell type (RCC-CC).
Immunohistochemistry using a PD-L1 polyclonal antibody was performed on a tissue microarray (TMA) that contained 115 surgical specimens of RCC-CC. Cases were classified based on the absence or presence of staining intensity in the cytoplasm and membranes of the tumor cells. Statistical analysis was used to determine the association of PD-L1 expression with classic prognostic factors and tumor recurrence.
PD-L1 expression was positive in 56.5 % of tumors. The univariate analysis showed a correlation between PD-L1 expression and nuclear Fuhrman grade (p = 0.021) and microvascular tumor embolization (p = 0.039). One hundred and four patients were monitored for a mean time of 115.7 months. Seventeen patients (16.3 %) suffered tumor recurrence. Negative outcomes were associated with higher nuclear grade tumors, PD-L1 expression, and the presence of microvascular invasion.
Our findings confirm that PD-L1 expression is an important prognostic factor in RCC-CC.
程序性死亡受体配体1（PD-L1）是一种来自T细胞共刺激分子家族的糖蛋白，由巨噬细胞组成性表达。在与肿瘤定向T细胞免疫反应抑制相关的人类癌症中观察到PD-L1的异常表达。文献中很少有报道评估PD-L1表达与预后的关系，特别是在肾透明细胞癌（RCC-CC）中。
使用PD-L1多克隆抗体对包含115例RCC-CC手术标本的组织微阵列（TMA）进行免疫组织化学检测。根据肿瘤细胞胞质和细胞膜中染色强度的有无对病例进行分类。采用统计分析确定PD-L1表达与经典预后因素及肿瘤复发的相关性。
56.5%的肿瘤中PD-L1表达呈阳性。单因素分析显示PD-L1表达与核Fuhrman分级（p = 0.021）和肿瘤微血管栓塞（p = 0.039）之间存在相关性。对104例患者进行了平均115.7个月的随访。17例患者（16.3%）出现肿瘤复发。不良结局与高核分级肿瘤、PD-L1表达及微血管侵犯的存在相关。
我们的研究结果证实，PD-L1表达是RCC-CC的一个重要预后因素。
