OVERALL SURVIVAL RATES IN RENAL CELL CARCINOMA PATIENTS AND SERUM sPD-1 AND sPD-L1 LEVELS

Introduction. Renal cell carcinoma (RCC) is one of the most aggressive tumors of the urinary system. Immune checkpoints such as PD-1 and PD-L1 play an important role in regulating the antitumor immune response. Serum levels of soluble forms of PD-1 (sPD-1) and PD-L1 (sPD-L1) may have some clinical significance in RCC, but their prognostic value remains poorly understood. The aim – to analyze the relationship between serum levels of sPD-1 and sPD-L1 in patients with renal cell carcinoma and overall survival rates. Material and methods. The study of sPD-1 and sPD-L1 levels was performed in the blood serum before treatment in 105 patients with RCC (63 men and 42 women) aged 33 to 81 years (median 60 years) at various stages of the disease (I – 55, II – 12, III – 17, IV – 21). Clear cell renal carcinoma was detected in 90 patients, chromophobe in 6, papillary type I in 6, papillary type II in 3, with the differentiation degree of G1 (9 tumors), G2 – 60, G3 –18, G4 – 12. The concentration of sPD-L1 and sPD-1 was determined in the blood serum of patients with renal neoplasms before treatment using the Human PD-L1 Platinum ELISA and Human PD-1 ELISA kits (Affimetrix, eBioscience, USA) according to the manu-facturer's instructions. To identify differences between values, one-way and multivariate analysis of variance (ANOVA) were applied. Survival curve analysis was performed using the Kaplan-Meier method, and survival curve comparisons were conducted using the Log-Rank test with Bonferroni cor-rection for multiple comparisons. A multivariate analysis of the impact of factors on overall survival was carried out using the Cox proportional hazards regression model. Differences were considered statistically significant at p < 0.05. All calculations were performed on a personal computer using the statistical software packages "Statistica for Windows" and SPSS. Results. Serum sPD-L1 levels were associated with worse overall survival in patients with RCC. Patients with sPD-L1 concentration ≥ 42.6 pg/mL demonstrated a significant reduction in 5-year overall survival compared to patients with low levels of this marker (p=0.0012). In multivariate analysis, sPD-L1 was an independent prognostic factor along with tumor size and the presence of metastases. A significant difference in overall survival in groups of patients with RCC was also shown when dividing patients by the sPD-1 level equal to 76 pg/ml, which confirms the significance of studying the content of soluble forms of these proteins in the blood serum of patients with RCC. Conclusions. High serum sPD-L1 levels are associated with poor prognosis in RCC and can be used as a potential biomarker for patient stratification. Further studies are needed to confirm the clinical significance of sPD-L1 and develop personalized treatment strategies for RCC.