The content of the soluble ligand of the immune checkpoint receptor (sPD-L1) was determined in the blood serum of 106 patients with renal cell carcinoma and 11 patients with benign kidney tumors by direct ELISA (Human sPD-L1 Platinum ELISA; Affimetrix, eBioscience). The control group included 19 healthy men and 18 women. Serum level of sPD-L1 significantly surpassed the control values in both patients with primary renal cancer (p<0.0001) and in patients examined during disease progression (p<0.05). In patients with benign kidney tumors, the level of this marker was significantly higher than in the control (p<0.05), but lower than in patients with renal cell carcinoma. The sPD-L1 level significantly increased with disease stage (p<0.001); it was higher in the presence of metastases in regional lymph nodes irrespective of their number (N1 or N2) than in the absence of metastases (N0); it was also increased in patients with distant metastases (M1) and patients with grade III-IV tumors in comparison with grade III-IV tumors (p<0.05). The highest sPD-L1 levels were recorded in patients with tumor size corresponding to T2 and T3 and decreased in patients with T4 tumors. Thus, sPD-L1 level in patients with renal cell carcinoma correlated with tumor grade and metastasizing and can be considered as a promising marker in monitoring of the effect of anti-PD1/PD-L1 therapy.
Bulletin of experimental biology and medicine. 2019 Jan 09 [Epub ahead of print]
N E Kushlinskii, E S Gershtein, A A Morozov, I O Goryacheva, M L Filipenko, A A Alferov, S D Bezhanova, V V Bazaev, I A Kazantseva
N. N. Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Moscow, Russia. ., N. N. Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Moscow, Russia., M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia., Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia.